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10 ELECTRICAL SYSTEM

10.1 General 141

10.1.1 Safety procedures ......................................................................................................... 141
10.1.2 Safety checks ................................................................................................................ 141
10.1.3 Hand terminal operation ................................................................................................ 142

10.2 Design and function 145

10.2.1 General functional description of the controllers ........................................................... 145
10.2.2 Multifunction Display Indicator (MDI)............................................................................. 148
10.2.3 Traction motor controller, AC1 ....................................................................................... 150
10.2.4 Steering servo controller, EPS-AC ................................................................................ 162
10.2.5 Wiring diagram .............................................................................................................. 167

10.3 Repair and maintenance instructions 168

10.3.1 Calibration, Speed controller ......................................................................................... 168
10.3.2 Calibrating the lifting and lowering controls ................................................................... 171
10.3.3 Save the parameters in the hand terminal's memory .................................................... 173
10.3.4 Downloading parameters from the hand terminal.......................................................... 175
10.3.5 Check the error codes ................................................................................................... 176
10.3.6 Changing the traction motor controller/steering servo controller ................................... 178
10.3.7 MDI replacement ........................................................................................................... 178
10.3.8 Changing the steering servo sensor.............................................................................. 179

10.4 Diagnostics and trouble shooting 180

10.4.1 Safety ............................................................................................................................ 180
10.4.2 Trouble shooting aids .................................................................................................... 180
10.4.3 Practical trouble shooting .............................................................................................. 180
10.4.4 Error codes .................................................................................................................... 182

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10 ELECTRICAL SYSTEM
10.1 General
10.1.1 Safety procedures
10.1.1.1 General
WARNING!
Working with electrical vehicles can result in personal injury.

• During all work on the truck’s electrical system, or in its immediate vicinity, rings,
watches and other metal objects must be removed since the battery capacity is such
that a short circuit through such an object can result in very serious burn injuries.
• Working with electrical vehicles can result in personal injury. All testing, trouble shooting
and adjusting must be carried out by authorised personnel. The drive wheel should run
free of the floor and be able to rotate freely during work.

10.1.1.2 Electronic controllers

• All the electronic controllers in the truck have multiple safety systems.
• When replacing or repairing the electronic controllers, or removing cables, the battery
should always be disconnected.

NOTE!
Incorrectly connected battery cables can destroy the electronic controllers.

WARNING!
During all work on the truck the drive wheel must be lifted up from the floor to
prevent accidents occurring. In order to avoid burn injuries, wrist watches and other
metal objects must be taken off.

After the power has been disconnected to the controller and work or trouble shooting is to be
conducted, there can be residual voltage in the capacitors for a few minutes, so take care
when using current-conducting tools during these minutes.

10.1.2 Safety checks

10.1.2.1 Servo controlled steering system
NOTE!
Checks on the external component functions in the servo controlled steering
system must be carried out after every service and after work has been carried out
on the electrical system. All functional tests of the safety system must be carried
out with the truck speed controller in its neutral position.

The servo controlled steering system embodies a number of safety monitors, partly to check
the controller circuits, but also such external circuits and components as the steering wheel
sensors, steering motor and end position sensors.
Functional testing of the servo controlled steering system safety functions must result in an
inability to activate the steering or drive systems and the brake not being able to go into its
unbraked state.
The monitoring system for the steering wheel sensors and their wiring is checked by
disconnecting the steering wheel sensor connector; this will result in an error code, see
Section 10.4.4.3, page 186.
The steering motor monitoring system is checked by disconnecting one of the wiring
connections to the motor, either at the motor or its controller. An error code must then be
shown if the steering wheel is moved, see Section 10.4.4.3, page 186.

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A dangerous condition arises if the end position switches for the steering function are
activated without the steered wheel being at the particular end position. This is monitored by
the controller sensing whether the sensor is activated even though the wheel is moving away
from the sensor. Test this by placing a jumper between pins 2 and 3 of the end position
sensor connector, see S4 and S5 respectively in the connections schematic diagram “Wiring
Diagram Handbook” and steering away from the respective sensor; check that an error code
is shown, see Section 10.4.4.3, page 186.

Figure 97. S4 and S5 connectors, seen from the wiring side

10.1.2.2 Traction motor system

The monitoring system checks that starting takes place in the correct order, i.e. that the
speed controller does not send an output signal when the truck is started by the key switch.
This function is tested by switching the key switch off, holding the speed control in the
affected position and switching the key switch back on again. The truck should not in that
case move until the speed controller has been in the neutral position.
A test of the motor circuit is not possible, since it is a 3-phase motor, but it is not necessary
anyway.
There are different systems to reduce the maximum speed of the truck, the lifting height of
the forks and the load. These systems are tested by lifting the forks above the microswitch
breaking height and loading with more than the preset weight. A tortoise is then shown on
the MDI display, refer to Section 10.2.2, page 148.

10.1.3 Hand terminal operation

The hand terminal is connected to the controllers via a 9-pole connector, connector "C". This
is normally covered by a rubber plug, which must be put back after the hand terminal has
been disconnected.

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Figure 98. Hand terminal/programming tool for adjusting the controller settings
All adjustments to the controller settings are made by means of the hand terminal.
With the aid of the six buttons on the hand terminal the settings of the traction motor
controller and steering servo controller respectively can be checked and adjusted.
See table 10.1 below for instructions on how the terminal is used in the menus.
Desired function Buttons to use
To step down through ROLL (1)
the menus:

To step up through the ROLL (2)

menus:

To enter a menu option: ENTER (3)

To increase the currently SET (5)

set value:

To reduce the currently SET (6)

set value:

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Desired function Buttons to use

To exit a menu option OUT (4) + ENTER (3)
and save the changed OUT (4) + OUT (4)

value
To exit a menu option
without saving the
changed value:

To select “CONFIG MENU” ROLL (1) + SET (5)

To also present all error messages by using the hand terminal, see Section 10.4.4, page
182.

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10.2 Design and function

10.2.1 General functional description of the controllers
10.2.1.1 Overview of the communication routes

Figure 99. Overview of the electrical system communication routes

1. Traction motor controller 2. CAN bus link
3. Steering servo controller 4. Multifunction Display Indicator (MDI)
5. Speed Controller 6. Traction motor
7. Lift control 8. Electrical panel
9. Hydraulic pump 10. Hydraulic valve
11. Hydraulic lift cylinder 12. Steering wheel
13. Steering servo motor

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10.2.1.2 Communication between the controllers

Figure 100. Communication between the controllers

The brain of the system is the traction motor controller (1) which via the CAN link
communicates with the controller for the steering servo motor (3) and the Multi Function
Display (MDI) (4).
The control units include self-diagnostic sections which can generate error codes. These
error codes are presented on the MDI (4) and on the hand terminal (se Section 02, page
17). The MDI also presents the total time during which the truck has been in operation and
the battery status.

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10.2.1.3 Traction motor controller

Figure 101. Overview of the traction controller for the traction motor.
When the speed control lever (5) is moved, the traction motor controller (1) sends a drive
voltage to the traction motor (6). A pulse transducer in the upper bearing of the traction
motor feeds back the motor rotation speed to the regulator, which alters the drive voltage to
produce a speed which is equivalent to the speed control.

Figure 102. Overview of the traction motor controller, hydraulic pump motor, lifting valve and lift cylinder

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When the control lever for the electrically controlled lifting movement (7) is moved, the
traction motor controller (1) sends a voltage to the lift motor contactor (8) which starts the lift
motor (9). The traction motor controller also sends information via the CAN link (2) to the
MDI (4) concerning how large the control movement is, and the lifting rate is then controlled
by the MDI, which gives a proportionally equally high control voltage to the control movement
to the control valve (10), which in turn gives a proportionally equally high hydraulic flow to the
lift cylinder (11), which provides the variable lifting and lowering rates.
On trucks with manual hydraulic valves the valve output is directly controlled by the position
of the lifting lever.

10.2.1.4 Steering servo controller

Figure 103. Overview of the steering servo controller, steering wheel and steering servo motor
When the steering wheel is turned, a signal is sent via a stepping motor on the steering
wheel (12) to a controller for the steering servo motor (3) which in turn transmits a
proportional drive voltage to the steering servo motor (13) which turns the drive wheel at the
desired speed and direction.

10.2.2 Multifunction Display Indicator (MDI)

10.2.2.1 Display description
Battery charging is indicated by means of five LEDs, four green and one red. When the
battery is fully charged all the green LEDs are on. The LEDs go off as the battery becomes
discharged, and when the battery charge has reached a level that requires the battery to be
recharged the red LED (steady) goes on.

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Figure 104. Multifunction Display Indicator (MDI)

1. Steady red light: Less than 10% battery 2. 25% battery capacity
capacity Flashing red light: Error code
indicating
3. 50% battery capacity 4. 75% battery capacity
5. 100% battery capacity 6. A flashing hourglass indicates that the hour
counter is active (Hourglass)
7. Error code shown/Service necessary 8. Reduced top speed (Tortoise)
(Spanner)
9. Alphanumeric display

10.2.2.2 Functionality
The display consists of a field with alphanumeric symbols and three different figurative
symbols.
The operating time, error codes and MDI software version are indicated by means of the
alphanumeric display:
• The operating hours counter indicates the number of hours the truck has been in
operation.
• The error codes are indicated by means of a pre-defined code and by the flashing of the
red LED.
• The software version is shown briefly on start up – EPXXX, where XXX represents the
version.
Other symbols:
• A tortoise shows that the maximum speed is reduced.
• The spanner is shown when an error code is indicated, or when a pre-programmed
service must be carried out.
• The hourglass flashes when the hour counter is active.

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10.2.3 Traction motor controller, AC1

10.2.3.1 General

Figure 105. Overview of the traction motor and hydraulic motor

10.2.3.2 Operation, traction motor controller AC1.

In an alternating current based regulation system it is important that the rotation of the motor
is synchronised by the traction controller. To enable this, a sensor, an incremental encoder, is
located in the motor, with two phases displaced by 90°. If these signals are disturbed or lost,
there will be no synchronisation between the motor and the traction controller. This results in
the motor running very slowly and drawing maximum current. Avoid running the motor in this
situation.

10.2.3.3 Connector, specification, traction motor controller AC1

The traction motor controller has three connectors
with input and output signals for valves, sensors,
switches, programming tools, etc. Each connector
pin is specified below with, where appropriate, the
voltage level in the connected condition.
Connector E1 (the figure shows the connector
from the wiring side).

Table 25. Connector E1 traction motor controller AC1

Pin Descriptions Remarks
E1.1 Controlling the Drive contactor. Controlled to B-
E1.2 Supply to Drive contactor +24V
E1.3 Controlling the electric brake Controlled to B-
E1.4 Controlling the pump contactor Controlled to B-

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Pin Descriptions Remarks

E1.5 Supply to pump contactor
E1.6 Control of vertically adjustable Controlled to B-
straddle legs valve
E1.7 CAN communication CAN Low
E1.8 Neg. supply to lifting/lowering B-
control
E1.9 Pos. supply to traction motor +4-5 V
encoder
E1.10 Neg. supply to traction motor B-
encoder
E1.11 Pos. supply to instruments +24 V
E1.12 Neg. supply to instruments B-
E1.13 Input from speed reduction switch From pressure switch, see note below (*)
E1.14 Input for lifting vertically adjustable +24V on activation
straddle legs
E1.15 Input for lowering vertically +24V on activation
adjustable straddle legs
E1.16 +12V supply to instruments +12 V
E1.17 CAN communication CAN High
E1.18 Signal from lift control Neutral = approx. 2.5V
Maximum lifting rate = approx. 4.5 V
Maximum lowering rate = approx. 1.0 V
E1.19 Input A from traction motor encoder Synchronises the motor movement with
phase shifted pulses from the encoder
E1.20 Input B from traction motor encoder
(*) The input from the pressure switch is filtered so that pressure fluctuations will
not trip the speed reduction. A change in the input value must be present for at
least 1 second before it will be accepted. During lifting and lowering
movements, no change in the input value will be accepted.

Connector E2 (the figure shows the connector

from the wiring side).

Table 26. Connector E2 traction motor controller AC1

Pin Descriptions Remarks
E2.1 Supply from electric lock +24 V
E2.2 Supply to external units +24 V
E2.3 Input from brake switch +24 V required for driving
E2.4 Not used in the A models
E2.5 Not used in the A models
E2.6 Not used in the A models

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Pin Descriptions Remarks

E2.7 Prop. valve: Accessories: Input from control switch
Stabilizers up
Man. valve:
Stabilizers up and down
E2.8 Prop. valve: Accessories: Input from control switch
Stabilizers down
Manual valve:
Starting the pump motor
E2.9 Acceleration reduction Reduction of steered wheel deflection
B- gives a reduction.
Lamp L1 must be working to obtain correct
operation
E2.10 Input signal from speed control Neutral = approx. 2.5 V
Maximum in the direction of the forks =
approx. 1.0 V
Maximum in the opposite direction = approx.
4.5 V
E2.11 Neg. supply to speed control B-
E2.12 Positive supply to speed and lift +5 V
controls

Connector C is used for connection of the "Hand terminal" programming tool.

Figure 106. Connector C (the illustration shows the connector on the controller)
The battery and motor connections are located separately on the motor controller.

Figure 107. Connect the battery and motor

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Table 27. Separate wiring connections

Pin Descriptions
-BATT Negative supply from the battery.
+BATT Positive supply from the battery.
U; V; W Motor connections, connected to the equivalent markings on the traction motor.

10.2.3.4 Menu tree, traction motor controller AC1

The following headings can be found in the traction motor controller's menu tree. Use the
hand terminal to see the menus, see Section 10.1.3, page 142.

Table 28. The main flow of the hand terminal menus, Traction motor controller
Display window Display window

AC1 ZAPI Vx.x

24V 250A 00000

MAIN MENU Table 29, CONFIG MENU (Not

page 154 available)
PARAMETER CHANGE SET MODEL

MAIN MENU Table 31, CONFIG MENU Table 35,

page 157 page 158
TESTER SET OPTION

MAIN MENU Table 32, CONFIG MENU Table 36,

page 158 page 160
SAVE PARAMETER ADJUSTMENTS

MAIN MENU Table 33,

page 158
RESTORE PARAMETER

MAIN MENU Table 34,

page 158
ALARMS

MAIN MENU (Not

available)
PROGRAM VACC

MAIN MENU (Not

available)
MOTOR DATA

To see what is included in each menu choice, look at the table referred to after each display
window.
Sub-menu specification for PARAMETER CHANGE

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Table 29. Delivery settings of the Zapi AC 1 Traction motor controller at A in the truck.
(Parameter Change Menu)
FUNCTION A Std A Std ATF+ Speed reduc. Speed reduc. EXPLANATION
Increased ALL With With
speed. 10 assistance stabilizers
km/h from the out less than
pressure 2m
switch
ACCELERATION 3 3 3 3 3 Acceleration ramp. A
DELAY lower value gives
faster acceleration
EXTRA ACC 5 5 5 5 5 Lengthened
DELAY acceleration ramp
with deflected drive
wheel
RELEASE 6 6 6 6 6 Braking torque at
BRAKING speed control to
neutral position
INVERSE 8 8 8 8 8 Braking torque in
BRAKING reversing direction
PEDAL 7 7 7 7 7 Must not be changed
BRAKING without verifying that
the braking distance
meets the EU
standards
SPEED LIMIT 7 7 7 7 7 Braking torque
BRAKING during reduced
throttle
BRAKE 5 5 5 5 5 Braking torque at
CUTBACK beginning of speed
reduction
MAX SPEED 94 119 94 94 94 Maximum speed in
FORW the machine housing
direction. May not be
increased after
delivery.
MAX SPEED 94 94 94 94 94 Maximum speed in
BACK the forks direction.
May not be
increased after
delivery.
CUTBACK 100 100 100 *1 0 Reduced speed.
SPEED 1
CUTBACK 70 70 100 70 70 Reduced speed to 5
SPEED 2 km/h above the free
lift stroke
H&S CUTBACK 10% 10% 10% 10% 10% Not used in the A
models
FREQUENCY 0.30 0.30 0.30 0.30 0.30 Lowest speed when
CREEP the truck starts off
MAXIMUM 9 9 9 9 9 Equivalent to the
CURRENT controller's
maximum current to
the motor
INCHING 0 0 0 0 0 Not used in the A
SPEED models

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FUNCTION A Std A Std ATF+ Speed reduc. Speed reduc. EXPLANATION

Increased ALL With With
speed. 10 assistance stabilizers
km/h from the out less than
pressure 2m
switch
INCHING TIME 0 0 0 0 0 Not used in the A
models
AUXILIARY 10 10 10 10 10 Must not be changed
TIME from this setting
LIFT CUTBACK 75 75 75 75 75 Adaptation of valve
operation for the lift
mode
MIN VALVE 1 5 5 5 5 5 The minimum
opening of the
proportional valve
MIN VALVE 2-4 0 0 0 0 0 The minimum
opening of the
On/Off valves
MAX VALVE 1 70 70 70 70 70 Maximum voltage to
the proportional
valve
MAX VALVE 2 255 255 255 255 255 Maximum voltage to
the lift stop valve
MAX VALVE 3 100 100 100 100 100 Maximum voltage to
and 4 the other valves
VALVES 24 24 24 24 24 System voltage to
VOLTAGE the valves
OPENING RAMP 0.2 0.2 0.2 0.2 0.2 Opening ramp for
V1-V4 the valves
CLOSING RAMP 0 0 0 0 0 Closing ramp for the
V1-V4 valves

Changes from the standard are indicated by bold text

*1 = Set to the value that is specified in KO.
Each parameter value can be altered in ten steps, see Table 30, page 155 below for the
available alternatives.

Table 30. Available parameter values, Traction motor controller

PARAMETER UNIT PARAMETER LEVEL IN STEPS OF 10
0 1 2 3 4 5 6 7 8 9
ACCELERATIO Sec. 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 5,5
N DELAY (*)
EXTRA ACCEL. (**) 1,5 1,8 2,1 2,4 2,7 3,0 3,5 4,0 4,5 5,0
DELAY (**)
RELEASE Sec. 5,5 5,0 4,5 4,0 3,5 3,0 2,5 2,0 1,5 1.0
BRAKING (***)
INVERSE Sec. 5,5 5,0 4,5 4,0 3,5 3,0 2,5 2,0 1,5 1.0
BRAKING (***)
PEDAL Sec. 5,5 5,0 4,5 4,0 3,5 3,0 2,5 2,0 1,5 1,0
BRAKING (***)
SPEED LIMIT Sec. 8.9 8.3 7.7 7.1 6.6 6.0 5.5 4.9 4.4 3.8
BRAKING (***)

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PARAMETER UNIT PARAMETER LEVEL IN STEPS OF 10

0 1 2 3 4 5 6 7 8 9
BRAKE Sec. 5,5 5,0 4,5 4,0 3,5 3,0 2,5 2,0 1,5 1,0
CUTBACK (***)
MAX SPEED Hz 67 72 78 89 94 99 109 114 119 124
FW
MAX SPEED Hz 67 72 78 89 94 99 109 114 119 124
BW
CUTBACK % Max Sp 10 20 30 40 50 60 70 80 90 100
SPEED 1
CUTBACK % Max Sp 10 20 30 40 50 60 70 80 90 100
SPEED 2
H&S CUTBACK % Max Sp 10 15 20 25 37 50 62 75 87 100
FREQUENCY Hz 0,3 0,6 0,9 1,2 1,5 1,8 2,1 2,4 2,7 3,0
CREEP
MAXIMUM % IMax 47 53 58 64 70 76 82 88 94 100
CURRENT
INCHING Hz 0 2 4 6 8 10 12 14 16 18
SPEED
INCHING TIME Sec. 0,3 1,0 2,0 2,8 3,63 4,5 5,4 6,2 7,1 8,0
AUXILIARY Sec. 0,0 0,4 0,8 1,4 2,0 3,0 4,0 6,0 8,0 10,0
TIME
LIFT CUTBACK % 10 15 20 25 37 50 62 75 87 100
MIN VALVE 1 This parameter can be adjusted in steps of 1, from 1 to 255
MIN VALVE 2 This parameter can be adjusted in steps of 1, from 1 to 255
MIN VALVE 3 This parameter can be adjusted in steps of 1, from 1 to 255
MIN VALVE 4 This parameter can be adjusted in steps of 1, from 1 to 255
MAX VALVE 1 This parameter can be adjusted in steps of 1, from 1 to 255
MAX VALVE 2 This parameter can be adjusted in steps of 1, from 1 to 255
VALVE 3 %V 12 20 25 40 50 60 70 80 90 100
VOLTAGE
VALVE 4 %V 12 20 25 40 50 60 70 80 90 100
VOLTAGE
VALVES V 12 24 36 48 60 72 80 96 120
VOLTAGE
V1 OPENING Sec. 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0
RAMP
V2 OPENING Sec. 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1.6 1,8 2,0
RAMP
V3 OPENING Sec. 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1.6 1,8 2,0
RAMP
V4 OPENING Sec. 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1.6 1,8 2,0
RAMP
V1 CLOSING Sec. 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1.6 1,8 2,0
RAMP
V2 CLOSING Sec. 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1.6 1,8 2,0
RAMP

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PARAMETER UNIT PARAMETER LEVEL IN STEPS OF 10

0 1 2 3 4 5 6 7 8 9
V3 CLOSING Sec. 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1.6 1,8 2,0
RAMP
V4 CLOSING Sec. 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1.6 1,8 2,0
RAMP

(*) The acceleration time is the time from 0 to 100 Hz; this is an average ramp that in practice
can be affected by different settings and loads
(**) EXTRA ACCEL. DELAY gives a multiple of the level set at ACCELERATION DELAY
Example:
• ACCELERATION DELAY=LEVEL 2
• EXTRA ACCEL. DELAY= LEVEL 5
• Gives a delay of 2.0 s * 3.0 = 6.0 s
(***) The braking affect is based on the deceleration ramp and is the time that elapses between
the controller pulses from 100 to 0 Hz, and is an average ramp that can be affected by
different settings and loads

Sub-menu specification for TESTS.

Table 31. Sub-menu "TESTS", Traction motor controller

TEST UNIT/STATUS DESCRIPTIONS
BATTERY VOLTAGE V Voltage to the electric lock
MOTOR VOLTAGE % Voltage to the motor as a percentage of the battery
voltage.
VOLTAGE BOOSTER % Voltage to the motor as a percentage of the battery
voltage while under load.
FREQUENCY Hz Pulse frequency of the voltage and current to the motor
ENCODER Hz The motor speed, measured as a frequency from the
encoder bearing in the motor
SLIP VALUE Hz Motor slippage, the difference between the controlling
frequency and the motor frequency
COS PHI cos(φ) for the motor, the phase shift between current
and voltage
CURRENT RMS A The rms (root mean square) value of the motor current
BATTERY CURRENT A Calculated current from the battery
BATTERY CHARGE % The battery's charging condition as a percentage
TEMPERATURE °C Temperature of the controller's heat sink
ACCELERATOR V Voltage from the speed controller shown as a voltage
to the left and a percentage to the right
LIFTING CONTROL V Voltage from the lift potentiometer shown as a voltage
to the left and a percentage to the right
LIFTING SWITCH ON/OFF Lift controller status
DESCENT SWITCH ON/OFF Lowering control status
FORW. SWITCH ON/OFF Status of the speed controller, forward direction
BACK. SWITCH ON/OFF Status of the speed controller, reverse direction
SEAT SWITCH ON/OFF Not used
H&S CUTBACK ON/OFF Not used
BRAKE SWITCH ON/OFF Foot pedal status ("if Input #4" option is set as
"Brake").

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TEST UNIT/STATUS DESCRIPTIONS

CUTBACK SWITCH #1 ON/OFF Status for input "Speed reducing 1"
CUTBACK SWITCH #2 ON/OFF Free lift switch status
DIGITAL INPUT #1 ON/OFF Lift switch status
DIGITAL INPUT #2 ON/OFF Status of the lowering switch during lowering ("If Input
#2" is set as "Present #1").

Table 32. Sub-menu "SAVE PARAMETER", Traction motor controller

SAVE PARAMETER With this menu all the set parameters can be
saved in the hand terminal's memory

Table 33. Sub-menu "RESTORE PARAMETERS", Traction motor controller

RESTORE PARAMETERS With this menu all the set parameters saved in the
hand terminal's memory can be downloaded to the
controller's memory

Table 34. Sub-menu "ALARMS", Traction motor controller

ALARMS This menu presents the following:
CODE = Error code
h = time (which operating hour) that the error code
occurred
N° = how many times this particular error code
has occurred
°C = temperature of the controller when the error
code was generated

The sub-menu that is obtained by pressing both buttons 1 and 5 on the hand terminal
simultaneously is specified below:
• See Table 35, page 158
• see Table 36, page 160.

Table 35. Sub-menu "SET OPTION", Traction motor controller

FUNCTION SELECTION DESCRIPTIONS
HYDRAULICS 0 Manual valve
1 Proportional valve with or without side stabilizers or
vertically adjustable straddle legs
2 Proportional valve with the combination of side
stabilizers and vertically adjustable straddle legs
TILLER SWITCH HANDLE Pin E2.3 is used as an input from the foot brake switch.
SEAT Pin E2.3 is used as an input from the seat switch.
SET INPUT #1 PRESENT Pin E1.13 is used as a speed reducing input.
OPTION #1 Pin E1.13 is used as a hand brake input.
CUTB DLY PRESENT
OPTION #1
SET INPUT #2 PRESENT
OPTION #1
SET INPUT #3 PRESENT
OPTION #1

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FUNCTION SELECTION DESCRIPTIONS

SET INPUT #4 BELLY Pin E2.7 is used as an input from the belly switch.
BRAKE Pin E2.7 is used as a brake input.
EXCLUSIVE Pin E2.7 is used as an "EXCLUSIVE HYDRO",
HYDRO hydraulic brake, input.
HOUR COUNTER RUNNING The hour meter records running hours
KEY ON The hour meter records hours spent with the key
switched on
BATTERY CHECK ON The battery indicator is active, and when the battery
has discharged by over 90% an alarm is generated
and the current to the traction motor is limited to half
the maximum.
OFF The battery indicator is active, but no alarm or
reduction takes place in the case of major discharge.
HYDRO KEY ON ON/OFF If this function is set to ON, the Traction motor
controller controls a hydraulic contactor when the key
is switched on if the function "aux output #1" is set to
"hydrocontactor" or "exclusive hydro"
STOP ON RAMP ON/OFF The ramp stop function is activated with the time that
has been set in the "auxiliary time" parameter; after
this time the function is affected by the parameter "aux
output #1" (See also Table 37, page 161).
OFF The ramp stop function is not activated (See also
Table 37, page 161).
AUX OUTPUT#1 HYDROCONTAC Pin E1.3 controls a hydraulic function when a
TOR directional, brake pedal is active or the truck is moving
(See also Table 37, page 161)
BRAKE Pin E1.3 controls the electric brake (See also Table 37,
page 161).
EXCLUSIVE Pin E1.3 drives a hydraulic function when “exclusive
HYDRO hydroinput” is active (See also Table 37, page 161).
AUX FUNCTION #1 PRESENT, with This function controls the delay to the stabilizers when
delay. a double-acting hydraulic function is used. Otherwise
ABSENT, without no delay is desired.
delay.
PEDAL BRAKING ANALOG, Option The mechanical brake has a potentiometer installed,
"Set input #4" set which means that when the speed control is released
to "Belly": the controller will apply a braking force that is related to
the amount of force with which the brake pedal is
depressed. The minimum braking force is determined
by the "Release braking" parameter (for gentle
braking). The greatest braking force is determined by
the "Pedal braking" parameter.
ANALOG, Option As for “Option BELLY” above, but with the addition that
"Set input #4" set the mechanical brake, as well as having a
to "Brake": potentiometer, also has a switch installed.
DIGITAL No analogue foot brake function
NONE The mechanical brake, does not have either a
potentiometer or a switch installed.
QUICK INVERSION BELLY The function is activated but not timer-controlled
TIMED The function is timer-controlled
NONE The function is switched off.

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FUNCTION SELECTION DESCRIPTIONS

AUX VOLTAGE #1 100 % The drive voltage to the emergency contactor and
electric brake as a percentage of battery voltage
PERFORMANCE OPTION #1 Set the power to "Low Performance".
OPTION #2 Set the power to "High Performance".
AUX FUNC1 PRESENT
OPTION #1
VALVE 1 TYPE OPTION #1 Electrically operated valve 1 is of the On/Off type
OPTION #2 Electrically operated valve 1 is of the proportional type
VALVE 2 TYPE OPTION #1 Electrically operated valve 2 is of the On/Off type.
OPTION #2 Electrically operated valve 2 is of the proportional type.
VALVE 3 TYPE OPTION #1 Electrically operated valve 3 is of the On/Off type
VALVE 4 TYPE OPTION #1 Electrically operated valve 4 is of the On/Off type

See Table 36, page 160 below for the specification of the sub-menu “ADJUSTMENTS”. The
sub-menu is accessed via buttons 1 and 5 on the hand terminal.

Table 36. Sub-menu "ADJUSTMENTS", Traction motor controller

FUNCTION VALUES EXPLANATION
Options Basic
setting
MIN LIFT ...V - Saves the lowest value from
the lift potentiometer when
the lift switch is activated
MAX LIFT ...V - Saves the highest value from
the lift potentiometer when
the lift switch is activated
MIN LOWER ...V - saves the lowest value from * See also Section
the lowering potentiometer 10.3.2, page 171
when the lowering switch is
activated
MAX LOWER ...V - saves the highest value from
the lowering potentiometer
when the lowering switch is
activated
SET BATTERY TYPE 24V/ 24 V select battery voltage
36V/
48V
ADJUST BATTERY ...V 23,8 V fine adjustment of the measured battery voltage
THROTTLE 0 ZONE ...% sets the deadband for the speed controller
THROTTLE X ZONE ...% 54 changes the speed controller characteristic
THROTTLE Y ZONE ...% 25 parameter to change the speed controller
characteristic
ADJUSTMENT #02 1-9 9 Sets the lower level for battery discharging
ADJUSTMENT #01 1-9 5 sets the upper level of battery discharging
CHECK UP DONE ON/OFF - Acknowledgement that Service has been carried out
CHECK UP TYPE

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FUNCTION VALUES EXPLANATION

Options Basic
setting
NONE 0 - Service reminder indicator switched off
OPTION 0 - "Alarm99" at 300 hours of operation
#01
OPTION 0 - "Alarm99" + red LED lit on the MDI at 340 hours of
#02 operation
OPTION 0 - "Alarm99" + red LED lit on the MDI at 340 hours of
#03 operation and the truck is stopped
OPTION 0 -
#04
OPTION 0 -
#05

On setting “AUX OUTPUT” and “RAMP ON/OFF” in the “SET OPTION” menu, different
functions are obtained at the E1:3 pin output. The combinations are specified in Table 37,
page 161 below.

Table 37. “Aux Output” set in combination with “Ramp On/Off, Traction motor controller
Aux Output Pin E1.3 Driver: Stop on Truck action when stopped on a ramp gradient
ramp
Brake Magnetic brake On The truck is held stationary with the aid of the traction
motor until the time set by the "auxiliary time"
parameter has elapsed, when the electric brake is
activated and the control signal to the traction motor is
terminated. Only use this combination if the negative
brake is installed.
Off The truck is held in place with the aid of the traction
motor, but slowly descends the ramp until the time set
by the "auxiliary time" parameter has elapsed, when
the electric brake is activated and the control signal to
the traction motor is terminated. Only use this
combination if the negative brake is installed.
Hydr. Cont A hydraulic unit On The truck is held stationary with the aid of the traction
contactor motor until the time set by the "auxiliary time"
parameter has elapsed, when the truck slowly
descends the ramp until it reaches level ground
Off The truck is not braked electrically but just rolls slowly
down a ramp until it reaches level ground.
Excl. Hydro A hydraulic unit On The truck is held stationary with the aid of the traction
contactor motor until the time set by the "auxiliary time"
parameter has elapsed, when the truck slowly
descends a ramp until it reaches level ground.
Off The truck is not braked electrically but just rolls slowly
down a ramp until it reaches level ground.

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10.2.4 Steering servo controller, EPS-AC

10.2.4.1 General

Figure 108. Steering servo controller

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10.2.4.2 Function, steering servo controller EPS-AC

Figure 109. Function overview of the steering servo system

1. Steering wheel 2. Stepping motor sensor
3. Stepping motor sensor wiring, 6 wires 4. Steering servo controller
5. Motor wiring 6. Steering servo motor
7. Wiring for safety control of traction motor brake 8. Traction motor brake
9. Traction motor 10. Drive wheel
11. End position sensor
A stepping motor sensor is connected to the steering wheel, which sends a signal to the
steering servo controller when the steering wheel is moved. The steering servo controller
sends a drive voltage to the steering servo motor which turns the drive wheel to the desired
direction at the desired speed. If anything wrong is indicated, the controller will remove the
drive signal from the drive motor and allow the drive motor brake to be applied and thereby
stop the truck.

Figure 110. End position switches S4 and S5

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The drive unit's end positions are indicated by inductive sensors, S4 and S5. When a sensor
is activated, the turning movement in that direction is halted. In order to supervise that the
turning movement is not stopped by the sensor before the drive unit has reached its end
position, the steering servo controller detects if the drive unit moves away from the sensor
without releasing the end position indication.
A third sensor, S8, detects whether the steered wheel has turned by more than 45 degrees
from the straight ahead direction. If this is the case, the drive motor's acceleration is reduced
so as to minimise the tipping torque that arises from sideways acceleration. The reduction in
acceleration is set by the parameter “EXTRA ACCEL DELAY” in the menu “PARAMETER
CHANGE” with the aid of the hand terminal (see Section 02, page 17).

Figure 111. Sensor locations, truck seen from above

10.2.4.3 Connector, specification, steering servo controller EPS-AC

The steering servo controller has three connectors
with inputs and outputs for sensors, programming
tools, etc. Each connector pin is specified below
with, where appropriate, the voltage level in the
connected condition.
Connector E3 (figure shows connector from the
cabling side).

Table 38. Connector E3 steering servo controller

Pin Descriptions Comment
E3.1 Not used in the A models
E3.2 Not used in the A models
E3.3 CAN communication CAN High
E3.4 Not used in the A models
E3.5 Speed reduction
E3.6 Not used in the A models
E3.7 From the steering wheel sensor Stepper motor
E3.8 Not used in the A models
E3.9 Not used in the A models
E3.10 From the steering wheel sensor Stepper motor

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Pin Descriptions Comment

E3.11 Control signal from speed control Neutral = approx. 2.5 V
Maximum in the direction of the forks = approx. 4.5
V
Maximum in the opposite direction = approx. 1.0 V
E3.12 Not used in the A models
E3.13 CAN communication CAN Low
E3.14 Not used in the A models
E3.15 Not used in the A models
E3.16 Not used in the A models
E3.17 Not used in the A models
E3.18 Not used in the A models
E3.19 Not used in the A models
E3.20 From the steering wheel sensor Stepper motor

Connector E4 (the figure shows the connector

from the wiring side).

Table 39. Connector E3 steering servo controller

Pin Descriptions Remarks
E4.1 Output from the safety relay +24 V that is disconnected in the case of a fault
in the steering servo
E4.2 Not used in the A models
E4.3 From the steering wheel sensor
E4.4 From the steering wheel sensor
E4.5 Not used in the A models
E4.6 End position signal Stops clockwise steering direction
E4.7 Input signal to the safety relay +24 V
E4.8 Not used in the A models
E4.9 From the steering wheel sensor
E4.10 Not used in the A models
E4.11 Not used in the A models
E4.12 End position signal Stops counterclockwise steering direction

Connector C is used for connection of the "Hand terminal" programming tool.

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Figure 112. Connector C (the figure shows the connector from the wiring side)
The battery and motor connections are located separately on the steering servo motor
controller.

Table 40. Separate wiring connections

Pin Descriptions
-BATT Negative supply from the battery.
+BATT Positive supply from the battery.
U; V; W Motor connections.

Figure 113. Battery and motor connections

10.2.4.4 Menu tree, steering servo controller EPS-AC

The following headings can be found in the steering servo controller's menu tree. Use the
hand terminal to see the menus, see Section 10.1.3, page 142.

Table 41. The main flow of the hand terminal menus

Display window Display window

AC1 ZAPI V0.0

12V 250A 00000

MAIN MENU Table 42, CONFIG MENU

page 167
PARAMETER CHANGE SET MODEL

MAIN MENU CONFIG MENU

TESTER SET OPTION

MAIN MENU CONFIG MENU

SAVE PARAMETER ADJUSTMENTS

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Display window Display window

MAIN MENU
RESTORE PARAMETER

MAIN MENU
ALARMS

MAIN MENU (Not

available)
PROGRAM VACC

MAIN MENU MOTOR DATA (Not

available)
MOTOR DATA

Under the menu selection “PARAMETER CHANGE”, certain parameters that are important
for turning are set, see Table 42, page 167.

Table 42. Sub-menu "PARAMETER CHANGE", steering servo controller

PARAMETER/ BASIC SETTING EXPLANATION
SPEED LIMIT 7 sets the maximum turning rate for controlling the drive wheel
AUX FUNCTION 3 2 sets the compensation of the steering wheel deflection sensitivity
at a high rate
SENSITIVITY 3 sets the steering wheel deflection sensitivity
AUX FUNCTION 2
CREEP SPEED 7 power reinforcement at small turning movements
PURSUIT RAMP - not used
COMPENSATION 2 sets the compensation for voltage drop in wiring and transistors
DESENSITIVITY - not used
POS ACCURACY - not used
AUXILIARY RAMP - not used
AUXILIARY TIME 1 sets the time for which the steered wheel is held in the locked
direction after the steering wheel has ceased to be affected
ANTIROLLBACK 40 % sets the power that holds the wheel in the locked direction after
the steering wheel has ceased to be affected
HOUR COUNTER RUNNING the time is counted as being while the system is active and
steering is possible
MICRO CHECK PRESENT The connected supervision system MUST NEVER BE
DISCONNECTED
ENCODER OFF there is no encoder in this system
CONTROL
FEEDBACK DEVICE OPTION 1 not used
DIRECTION GAUGE OPTION 1 not used
AUTO INPUT ACTIVE 1 not used
AUX FUNCTION 1 0 not used

10.2.5 Wiring diagram

All the wiring diagrams can be found in a separate “Wiring diagram handbook”, contact Atlet
for further information.
The relevant wiring diagrams for A_Ergo are specified in the table below.

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Descriptions Machine Reference Document

code
Wiring diagram A-ERGO 104100
Circuit diagram A-ERGO 104101

10.3 Repair and maintenance instructions

10.3.1 Calibration, Speed controller
The drive motion is controlled by a linear lever that is supplied with approx. 5 V.
In the neutral position, the lever delivers about 2.5 V. When the level is moved to drive
forward, the output signal from the sensor increases towards 4.5 V, and reduces towards 1.0
V when the lever is moved backwards.
In order to calibrate the start position and the maximum position, the Hand terminal is used,
see Section 10.1.3, page 142 for the user instructions.
1) Connect the Hand terminal, the display shows:

AC1 ZAPI V x.x

24V 250A 00000

2) After starting, press both the upper outer buttons.

Figure 114. Keyboard

CONFIG MENU
SET MODEL

3) Step down to the Adjustment menu.

CONFIG MENU
ADJUSMENT

4) Press ENTER to access the menu.

5) Step to ACCELER MIN.

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ADJUSTMENT
ACCELER MIN

6) Press ENTER.

7) The display then shows the current value.

ACCELER MIN
...V

8) Move the control to a position that is suitable for starting the driving movement in the
"drive wheel direction". If the control is too far from neutral, the controllability is reduced,
a change towards the voltage neutral value by about 0.2 V may be suitable. (As the
control is affected by the direction away from the forks, the voltage increases. And as
the control is affected by the direction towards the forks, the voltage decreases)
9) Press OUT.

10) Press ENTER if the value is to be saved.

Press OUT if the value is NOT to be saved.

11) The display now shows:

CONFIG MENU
ADJUSTMENT

12) Press ENTER to access the menu.

13) Step to ACCELER MAX.

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ADJUSTMENT
ACCELER MAX

14) Press ENTER.

15) The display then shows the current value.

ACCELER MAX
...V

16) Move the control to the maximum speed position in the "drive wheel direction".
17) Press OUT.

18) Press ENTER to save.

19) Step to SET ACC REV MIN and repeat the procedure from step 8 to step 12 in the forks
direction. Then step to SET ACC REV MAX and repeat the procedure from step 14 to
step 18, also in the forks direction.
20) Press ENTER if the value is to be saved.

Press OUT if the value is NOT to be saved.

21) The display now shows:

CONFIG MENU
ADJUSTMENT

22) To return to the main menu, press “OUT”.

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The speed controller is now calibrated in both directions. Test the sensitivity, and if any
parameter does not feel good, recalibrate that particular function.

10.3.2 Calibrating the lifting and lowering controls

This function stores the minimum and maximum values for the lifting and driving controls.
The minimum value is the lever position where the respective movement will start, and the
maximum value is that where the movement has reached maximum speed.
The lifting and lowering movements are controlled by a linear lever that is supplied with 5 V.
In the neutral position, the lever delivers about 2.5 V. When the level is moved to the lift
position, the voltage increases towards 4.5 V, and reduces towards 1.0 V during lowering.
In order to calibrate the start position and the maximum position, the Hand terminal is used.
1) Connect the Hand terminal, the display shows:

AC1 ZAPI Vx.x

12V 250A 00000

2) After starting, press both the upper outer buttons.

Figure 115. Keyboard

CONFIG MENU
SET MODEL

3) Step down to the Adjustment menu.

CONFIG MENU
ADJUSTMENT

4) Press ENTER to access this function.

5) Step to MIN LIFT.

ADJUSTMENT
MIN LIFT

6) Press ENTER.

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7) The display then shows the current value.

MIN LIFT
...V

8) Move the control to a position that is suitable for starting the lifting movement.
9) Press OUT.

10) Press ENTER if the value is to be saved.

Press OUT if the value is NOT to be saved.

11) The display now shows:

CONFIG MENU
ADJUSTMENT

12) Press ENTER to access this function.

13) Step to MAX LIFT.

ADJUSTMENT
MAX LIFT

14) Press ENTER.

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15) The display then shows the current value.

MAX LIFT
...V

16) Move the control to the maximum lift position.

17) Press OUT.

18) Press ENTER if the value is to be saved.

Press OUT if the value is NOT to be saved.

19) The display now shows:

CONFIG MENU
ADJUSTMENT

20) Repeat the procedure for “MIN LOWERING” and “MAX LOWERING” respectively.
21) To return to the main menu, press “OUT”.

The lifting and lowering controls are now calibrated.

10.3.3 Save the parameters in the hand terminal's memory

This function saves the set parameters in the hand terminal's memory.
These parameters can then be loaded into a different controller by using the “RESTORE”
function.
The following data can be saved by using “SAVE PARAMETERS”:
1. All parameter values ("PARAMETER CHANGE").
2. Options (“SET OPTIONS”).
3. Battery level (“BATTERY LEVEL”).
1) Connect the Hand terminal, the display shows:

AC1 ZAPI Vx.x

24V 250A 00000

2) After starting, press the button 3, ENTER to access the “MAIN MENU”.

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MAIN MENU
PARAMETER CHANGE

3) Step to SAVE PARAM.

MAIN MENU
SAVE PARAM.

4) Press ENTER to access the menu.

5) If this function has been used before, that is indicated by a two-digit reference.

SELECT: Mod. 00
FREE

6) Step up, button 2, or down, button 1, until the window indicates FREE.

SELECT: Mod. 01
FREE

7) Press ENTER to save.

8) The display shows what has been saved, beneath what has been done.

READING...
ACCELER DELAY (ECC)

9) When all is ready the window shows:

MAIN MENU
SAVE PARAM.

10) Press OUT to return to the start window.

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AC1 ZAPI Vx.x

24V 250A 00000

10.3.4 Downloading parameters from the hand terminal

This function allows the parameters saved in the hand terminal's memory to be downloaded
to the controller.
The following data can be downloaded by using “RESTORE PARAMETERS”:
1. All parameter values ("PARAMETER CHANGE").
2. Options (“SET OPTIONS”).
3. Battery level (“BATTERY LEVEL”).

NOTE!
All the values in the controller's memory will be overwritten by the parameters
saved in the hand terminal.

1) Connect the Hand terminal, the display shows:

AC1 ZAPI Vx.x

24V 250A 00000

2) After starting, press the button 3, ENTER to access the “MAIN MENU”.

Figure 116. Keyboard

MAIN MENU
PARAMETER CHANGE

3) Step to RESTORE PARAM.

MAIN MENU
RESTORE PARAM.

4) Press ENTER to access the menu.

5) The display will show the models that are saved by a two-digit code.

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SELECT: Mod. 00
AC1 ZAPI V1

6) Step up, button 2, or down, button 1, until the desired model is shown.

SELECT: Mod. 01
AC1 ZAPI V1

7) Press ENTER to start the transfer.

8) The display asks if you are sure.

ARE YOU SURE?

YES = ENTER NO = OUT

9) The display shows what has been saved, beneath what has been done.

STORING...
ACCELER DELAY

10) When all is ready the window shows:

MAIN MENU
RESTORE PARAM.

11) Press OUT to return to the start window.

AC1 ZAPI Vx.x

24V 250A 00000

10.3.5 Check the error codes

The controller remembers the five most recent errors that have occurred. For each error that
has been saved, the error code itself, the number of times this particular error has occurred,
the hour meter reading at the time of each error and the controller's temperature are shown.
1) Connect the Hand terminal, the display shows:

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AC1 ZAPI Vx.x

24V 250A 00000

2) After starting, press the button 3, ENTER to access the “MAIN MENU”.

MAIN MENU
PARAMETER CHANGE

3) Step to ALARMS.

MAIN MENU ALARMS

ALARMS

4) Press ENTER to access the menu.

5) The display will show the error code, the number of times this particular error has
occurred and the temperature of the controller at the time the error occurred.

CODE
00005 #02 20ºC

6) Step up, button 2, to see the next error, or step down, button 1, to see previous errors.

CODE
00007 #03 18ºC

7) To exit the ALARM window press OUT.

8) The question of whether to reset the error code list to zero will be shown.

CLEAR LOGBOOK?
YES = ENTER NO = OUT

9) Press ENTER for yes and OUT for no.

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10) To exit the ALARM window press OUT.

AC1 ZAPI Vx.x

24V 250A 00000

10.3.6 Changing the traction motor controller/steering servo controller

1) If possible, save the current parameter settings, see Section 10.3.3, page 173, before
removal.
2) Remove electrical power from the truck.
3) Open out the electrical panel to gain access to the controller.
4) Disconnect the motor wiring and supply wiring.
5) Pull out the operating wiring, connectors E1 and E2, and E3 and E4 respectively.
6) Unscrew the controller.
7) Steering servo controller: Scrape clean the contact surface between the controller and
its attachment plate.
8) Steering servo controller: Apply a layer of heat-conducting paste between the
controller and the attachment plate.
9) Fit the controller.
10) Connect the operating wiring, connectors E1 and E2, and E3 and E4 respectively.
11) Connect the motor wiring and supply wiring.
12) Download the parameter settings that the previous controller had (assuming that item 1
above was carried out), see Section 10.3.4, page 175 .

10.3.7 MDI replacement

1) Switch off the current to the truck and pull out the battery plug.
2) Raise the control panel, see Section 07, page 93 for the procedure.
3) Disconnect connector E5.
4) Release the securing hook and pull out the MDI.
5) Refit in the reverse order.

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10.3.8 Changing the steering servo sensor

10.3.8.1 General

Figure 117. Location of the steering servo sensor, truck seen from above

Figure 118. Fitting the steering servo sensor

10.3.8.2 Removing the steering servo sensor

1) Remove electrical power from the truck.
2) Remove the locking nut (item 1, Figure 118, page 179) from the sensor.
3) Screw out the sensor (and follow up with the wiring, so it des not get twisted).

10.3.8.3 Fitting the steering servo sensor

1) Screw in the sensor (item 1, Figure 118, page 179) and follow up with the wiring, so it
des not get twisted, until it meets the cam.
2) Unscrew the sensor1 turn and secure it with the nut.
3) Lock the nut with thread locking fluid.

NOTE!
The nut must be locked with thread locking fluid. Ensure that no thread locking
fluid enters the threaded hole.

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10.4 Diagnostics and trouble shooting

10.4.1 Safety
NOTE!
See Section 10.1.1, page 141 before any work starts on the truck electrical
system.

10.4.2 Trouble shooting aids

10.4.2.1 Circuit diagram
The circuit diagram is the basis for the work of trouble shooting, as it provides an overview of
the electrical system functions; from this it is possible to locate faults.
A wiring diagram is supplied with each truck, or can be found in a separate “Wiring diagram
handbook”.

10.4.2.2 Wiring diagram

A connections schematic diagram is used to translate the theoretical solutions of the circuit
diagram into practical connections in the truck.
A connections diagram is supplied with each truck, or can be found in a separate “Wiring
diagram handbook”.

10.4.2.3 Error codes

Error codes are read on the MDI, see Section 10.2.2, page 148, and on the hand terminal,
se Section 10.1.3, page 142
The meanings of the error codes are specified in the following section:
• Traction motor controller, see: Section 10.4.4.2, page 183.
• Steering servo controller, see: Section 10.4.4.3, page 186.
• Error codes in the display, see: Section 10.4.4.1, page 182.

10.4.2.4 Multimeter
When using a multimeter, all the measurements must use B- as a reference.
The most reliable trouble shooting method is obtained with the negative supply wire
connected as close to the battery as possible, but an exception is when for example voltage
levels from the speed control are to be measured; in this case it is best to use B- at the
respective controller.

10.4.2.5 Input and output specifications

Connector pin numbering, see
• Table 25, page 150
• Table 26, page 151
• Table 38, page 164
• Table 39, page 165

10.4.3 Practical trouble shooting

10.4.3.1 General
For all trouble shooting in the electrical system it is recommended to first connect the Hand
terminal to the appropriate controller and see if this is producing any error message, which is
translated in the tables, see Section 10.4.4, page 182.

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Faults which at first sight seem to be associated with a controller may actually be due to a
fault in another unit, so first look for error messages in all units, if the first does not show one
that applies.

10.4.3.2 Error in the drive function

1) Connect the hand terminal to the traction motor controller and read off any error
message; these appear automatically once the hand terminal has logged on to the
traction motor controller.
2) If no error message is present, operate the brake switch and the speed control to see if
an error message appears. If one does not, go over to the test menu and read off the
brake switch function (Brake switch Table 31, page 157) and the output signal from the
speed controller (ACCELERATOR).
• see Section 10.3.1, page 168
There is no separate direction switch, the direction is determined by the throttle
voltage from the speed control. In the test menu, however, the choice of direction
can be studied by means of the "FORW SWITCH" and "BACK SWITCH"
(indications that the system has identified the direction of travel)
• see Table 31, page 157
3) Also check the positions of the speed reduction switches by using "SPEED SWITCH 1
and 2" in the test menu.
• see Table 31, page 157
4) Also check the current to the motor "CURRENT RMS". If there is current to the motor
but it does not move, or only moves slowly, this can be due to a fault in the encoder
signal from the motor, which can be studied by using "ENCODER" in the test menu.
• see Table 31, page 157
• If the encoder is faulty, the encoder bearing in the drive motor must be changed,
see Section 05, page 47.
5) At over +75 °C in the traction motor controller the maximum motor current is gradually
reduced with increasing temperature. At 100 °C it is reduced to zero.
This is presented as a "HIGH TEMPERATURE" error message on the hand terminal,
and as 16A61 on the instrument display (MDI).
6) If the error message "VACC NOT OK" is shown on the hand terminal, or 16A78 on the
instrument display (MDI), the fault may be that the speed control is incorrectly
calibrated.
• To calibrate the speed control, see Section 10.3.1, page 168.

10.4.3.3 Fault in the servo steering system

1) Connect the Hand terminal to the controller.
2) Read off any error messages, and read the cause and solution in Section 10.4.4, page
182.

10.4.3.4 Fault in the lifting/lowering system

1) Connect the Hand terminal to the traction motor controller and read off any error
messages, see Section 10.4.4, page 182.
2) Check the system settings against Table 29, page 154.
3) Use the Test menu, see Table 31, page 157, to study the following:

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• Input voltage from the "LIFTING CONTROL"

lifting/lowering control with:
• If the system is getting the lift "LIFTING SWITCH"
demand with:
• If the system is getting the lower "DESCENT SWITCH"
demand with:

10.4.3.5 Fault symptoms, Traction motor controller

Table 43. Fault symptoms
Symptom Possible cause Procedure
Low voltage to the traction motor Battery voltage is below the set Charge the battery
limit value
The system does not start Incorrect start up sequence The electric lock must be
energised before the speed
control can be moved

10.4.4 Error codes

10.4.4.1 MDI error codes

1. Indication of which controller is generating an 2. Alarm number

alarm.
3. A=Alarm
The controller that is generating an alarm can be identified by means of the two first digits in
the error code, see Table 44, page 182.

Table 44. Indication of which controller is generating an alarm

Controller code Explanation Error codes
02 Traction motor controller See Section 10.4.4.2, page 183.
06 Steering servo controller See Section 10.4.4.3, page 186.
16 Multifunction Display See Table 45, page 183.

Certain error codes are set uniquely by the MDI, see Table 45, page 183.

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Table 45. Error codes presented in the Multi Function Display, MDI
MDI fault Hand terminal Explanation Control/Procedure
code error code
16A67 CAN BUS KO CAN bus connector link poor. 1. Check the wiring and
connections.
2. If OK, change controller.
16A70 HW OVER CURR Valves connected to E5.4 and/or Check the current consumption.
E5.6 short circuited. Change the valve when the
current consumption exceeds 2
A.
16A74 DRIVER The MDI PRC has detected a short Check the current consumption
SHORTED circuit at the ON/OFF valves. of the ON/OFF valves. Change
the valve when the current
consumption exceeds 2 A.
16A75 CONTACTOR Internal fault in the MDI. Change MDI.
DRIVER
16A89 PEPV NOT OK There is either no or low positive Check that the voltage at E5.1 =
voltage to the valves. B+. If OK, change the MDI.
16A90 NEVP1 NOT OK Problem with one of the
proportional valve controls.

10.4.4.2 Traction motor controller error codes

The following error codes are set by the traction motor controller, Table 46, page 183.

Table 46. Traction motor controller AC1 error codes

Error code indicating Explanation Control/Procedure
MDI Hand
terminal
02A00 BATTERY If the "BATTERY Charge the battery.
LOW CHECK" function is
activated and the battery
has less than 10%
remaining, the current
will be reduced to half
the set level and at the
same time an error code
will be shown.
02A08 WATCHDOG This is an internal test Change the controller.
that is performed both
during driving and when
stationary; it is the logic
that is tested.
02A13 EEPROM KO Error in the area that Switch the key on and off once:
includes adjustable • If the error code has disappeared, note that
parameters. all the settable parameters have returned to
their default values and that new settings
must be made.
• If the error remains, change the controller.
02A16 AUX OUTPUT When the key is switched Change the controller.
KO on, check the μP Drive
contactor, the driver for
the electric brake. If the
answer is not correct, an
error code will appear.

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Error code indicating Explanation Control/Procedure

MDI Hand
terminal
02A17 LOGIC A fault in the hardware Change the controller.
FAILURE #3 section that handles the
overcurrent protection to
the different motor
phases.
02A18 LOGIC A fault in the hardware Change the controller.
FAILURE #2 section that handles the
voltage supply to the
different motor phases.
02A19 LOGIC Reports that the 1. an actual over/undervoltage has occurred.
FAILURE #1 over/undervoltage 2. change the controller.
protection has been
3. Check the plugs.
activated.
4. look for burnt pins.
02A30 / VMN LOW/ This test is done during 1. problem with wiring to the motor,
02A31 VMN HIGH start-up and when connections, motor windings or earth
stationary. connection.
2. change the controller.
02A37 CONTACTOR Drive contactor closed on 1. Check the contactor and wiring
CLOSED start-up. 2. Change the traction motor controller.
02A38 CONTACTOR The logic has sent a 1. break in the wiring to the coil.
OPEN voltage to the main 2. main contactor defective.
contactor coil, and this is
expected to close, but
the contacts have not
closed.
02A53 STBY in HIGH Check that the current is 1. defective current sensor.
zero when the truck is 2. change the controller.
stationary If not, stop the
truck.
02A55 PROG LIFT This error code reports Error in the program for the lifting/lowering
LEVER that there is an error in controls.
the program for the
lifting/lowering controls.
02A60 CAPACITOR Internal fault in the Change the controller.
CHARGE controller.
02A61 HIGH Heat sink temperature 1. Check the fan on the electrical panel.
TEMPERATU above 75°C. The current 2. No action if the truck does not show any
RE is limited in relation to the other symptoms.
excessive temperature.
3. At reduced traction, improve the cooling.
The controller shuts
down completely at
100°C.
02A67 CAN-BUS KO Monitoring of CAN bus. 1. Check the wiring.
2. change the controller.
02A70 ENCODER Incorrect signal from the 1. Check the encoder signal with the hand
ERROR rotation speed feedback terminal.
sensor in the traction 2. Check the wiring between the traction motor
motor (Encoder). encoder and the traction motor controller.

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Error code indicating Explanation Control/Procedure

MDI Hand
terminal
02A71 HANDBRAKE The truck will not start 1. Faulty switch.
because the foot brake 2. The driver has followed the wrong sequence
switch has not been during start up.
operated.
3. Faulty wiring.
4. If the error remains, change the controller.
02A73 THERMIC Incorrect value from the Change the controller.
SENSOR KO sensor which controls the
temperature of the
controller.
02A74 DRIVER Internal fault in the Change the controller.
SHORTED controller.
02A75 CONTACTOR Internal fault in the Change the controller.
DRIVER controller.
02A76 COIL When the key is switched 1. Check for a possible short circuit in the
SHORTED on, check the μP Drive wiring, and that the coil has the correct
contactor for FF SR. If resistance.
the answer is not correct, 2. Change the controller.
an error code will appear;
in the case of this fault,
change the controller. FF
SR performs a hardware
check on the current to
the drive contactor coil,
and if this is too high the
drive contactor opens
and an error code is
shown.
02A78 VACC NOT This test is done when 1. speed control not properly calibrated.
OK stationary. The reason for 2. speed control incorrect.
the alarm is that the
3. check the lift control.
voltage from the speed
control is 1 Volt higher
than the minimum value
that has been
programmed in the
PROGRAM VACC
function.
02A79 INCORRECT This alarm reports that 1. speed control incorrect.
START an incorrect start has 2. the driver has followed the wrong sequence
taken place. during start up.
3. faulty wiring.
4. if the error remains, change the controller.
02A80 FORW + This test is performed 1. the driver has followed the wrong sequence
BACK continuously and means during start up.
that two different drive 2. faulty wiring.
directions have been
3. if the fault remains, change the controller.
"requested"
simultaneously.
02A86 PEDAL WIRE This error code reports Check the wiring to the speed control.
KO that there is a fault in the
wiring to the speed
control potentiometer.
02A89 PEV NOT OK The voltage at the "PEV" Change the controller.
output is incorrect.

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Error code indicating Explanation Control/Procedure

MDI Hand
terminal
02A93 INPUT This alarm is detected Check with a multimeter if the actual battery
ERROR #2 only during starting. voltage is above or below the stated limit value. If
Meaning: The battery not, use the Zapi console and check "BATTERY
voltage has deviated VOLTAGE" n the test menu.
more than 20% from its If a deviation is found between the actual battery
nominal value. voltage and the battery voltage on the Zapi
console, an adjustment is required: Go to the
adjustment menu. Check that "SET BATTERY
TYPE" is 24 V and then adjust the parameter
"ADJUST BATTERY" to the correct value. Then
switch off and switch on the truck again.
02A94 CURR.SENS Fault in the current feed Change the controller.
KO system.
02A99 INPUT The speed control has • Check the speed control and its wiring.
ERROR #1 two output signals, a • Measure the voltage levels.
primary that is centred
around 2.5 Volts and
increases when driving in
the machine housing
direction, and reduces in
the forks direction, and a
secondary that is also
centred around 2.5 Volts
but goes in the opposite
direction when driving.
This is used as a
checking signal and goes
to the steering servo pin
E3.11. From there it goes
via the CAN system to
the traction motor
controller and is
compared with the
primary signal. If they do
not agree, the system will
go into its neutral state
and the brake will be
activated.
Poor connection to the • Check at connector E3 that there are good
speed control. contact surfaces.
• Check measure E3.11.

10.4.4.3 Steering servo controller error codes

The following error codes are set by the steering servo controller, Table 47, page 187

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Table 47. Steering servo controller EPS error codes

Error code Explanation Control/Procedure
indicating
MDI Hand
terminal
06A08 MICRO Internal fault in the steering if the error remains, change the controller.
SLAVE servo controller.
06A13 EEPROM Internal fault in the steering Perform a “CLEAR EEPROM”
KO servo controller. • Use the hand terminal, press on both
the SET buttons (5+6) at the same time
to enter the “ALARM CONFIG MENU”
• Step forward to “CLEAR EEPROM”
• Press “ENTER” (3+3) twice. If the error
remains, change the controller.
06A16 LOGIC Internal fault in the steering if the error remains, change the controller.
FAILURE #4 servo controller. High rest
voltage between the U and W
phases.
06A17 LOGIC Internal fault in the steering if the error remains, change the controller.
FAILURE #3 servo controller. High rest
voltage between the V and U
phases.
06A18 LOGIC Arises when the desired if the error remains, change the controller.
FAILURE #2 voltage between the U and W
phases is different from the
measured value.
06A19 LOGIC Arises when the desired if the error remains, change the controller.
FAILURE #1 voltage between the U and V
phases is different from the
measured value.
06A28 S.P OUT OF Arises when the potentiometer • Check the steering angle
RANGE for the desired steering angle potentiometer's connections and wiring.
has a poor electrical contact. • If no fault is found, change the
potentiometer.
06A29 F.B OUT OF Arises when the potentiometer • Check the steering angle
RANGE for feedback of the steering potentiometer's connections and wiring.
angle has a poor electrical • If no fault is found, change the
contact. potentiometer.
06A32 VMN NOT Arises when the initial rest if the error remains, change the controller.
OK voltage between at least one
phase and signal earth is high.
06A37 KM Arises when the safety contact • Check the electrical installation, pins
CLOSED closes early. E4.1 and E4.7.
• Check the functions of any switches and
relays in the circuit.
• If no fault is found, change the controller.
06A38 KM OPEN Arises when the safety contact • Check the functions of any switches and
opens late. relays in the circuit.
• If no fault is found, change the controller.
06A39 KS CLOSED Arises when the safety contact • Check the electrical installation, pins
closes early. E4.1 and E4.7.
• Check the functions of any switches and
relays in the circuit.
• If no fault is found, change the controller.

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Error code Explanation Control/Procedure

indicating
MDI Hand
terminal
06A40 KS OPEN Arises when the safety contact • Check the functions of any switches and
opens late. relays in the circuit.
• If no fault is found, change the controller.
06A48 MAIN CONT Arises on initiation of the CAN Probably an alarm from the traction motor
OPEN bus system synchronization controller AC1.
with the traction motor
controller AC1 if the main
contactor does not close.
06A53 STBY in Rest voltage too high. Change the controller.
HIGH
06A61 HIGH Temperature controller over 76 Switch off the truck and allow the unit to cool.
TEMPERAT °C.
URE
06A67 KEYOFF A warning that the Sicus The error code disappears if the Sicus
module is giving a “key off” module removes the command.
command via the CAN bus.
06A68 One of the drive unit position • Check the operation of both position
limit switches (S4 or S5) is limit switches.
closed when it should be open. • Adjust the switches S4 and S5.
06A70 HIGH Arises if the current amplifier's if the error remains, change the controller.
CURRENT output signal gives a higher
value than the Imax level for
longer than one second.
06A71 POWER Arises in the case of a loss of Check measure the steering servo motor and
FAILURE #3 phase in the steering servo its wiring.
motor U, V, W.
06A72 POWER Arises in the case of a loss of Check measure the steering servo motor and
FAILURE #2 phase in the steering servo its wiring.
motor U, V, W.
06A73 POWER Arises in the case of a loss of Check measure the steering servo motor and
FAILURE #1 phase in the steering servo its wiring.
motor U, V, W.
06A81 DATA Arises when the operator alters Switching the key off and on resets the alarm.
ACQUISITI “ADJUSTMENT #1” to level 1.
ON
06A94 MICRO The steering wheel deflection Check the connections
SLAVE KO set point and the actual value - stepping motor sensor
from the drive wheel do not - steering servo motor
agree.
- steering position limit switch
if the error remains, change the controller.

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Error code Explanation Control/Procedure

indicating
MDI Hand
terminal
06A95 D LINE Arises when the signal from the 1. Check the stepping motor wiring.
SENSOR stepping motor sensor. pin 2. Measure the resistance between pin
KO E4.3 EPS, is open. E4.3 and signal earth (should be close
to 30 Ω)
3. if the error remains, change the stepping
motor sensor.
06A96 Q LINE Arises when the signal from the 1. Check the stepping motor wiring.
SENSOR stepping motor sensor. pin 2. Measure the resistance between pin
KO E4.9 EPS, is open. E4.9 and signal earth (should be close
to 30 Ω)
3. if the error remains, change the stepping
motor sensor.

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