Redditch

Manual Supplement

For

RS Vane Compressors

KEB Inverter Drive

User and Distributor Edition

ST16132-00 Issue C 04/2005

Introduction

1 The CompAir Regulated Speed Vane Compressor has been designed to save energy and operating cost when compared
with a fixed speed compressor of similar size. The saving is achieved by automatically regulating the compressor speed to
precisely match the compressor output to match the system flow and pressure requirements.
2 The system pressure is measured and converted into an electrical signal by an integral pressure transducer. The
compressor speed control unit senses the transducer signal and adjusts the electric motor speed to maintain a constant
“target” pressure. If the system pressure rises above the target pressure the electric motor speed will decrease,
conversely, if the system pressure falls below the target pressure the motor speed will increase. The speed will vary
between minimum and maximum limits dependent upon flow requirements.
3 Adjustments may be made to the factory set pressures to suit particular system requirements, refer to Pressure Control
Adjustment section below. Operating the compressor to suit the lowest acceptable system pressure will minimise energy
costs.

Safety Notice

Before installing or operating the RS compressor refer to the standard fixed speed user handbook supplied with the RS
compressor, in particular:

‘General Health and Safety Precautions’ and

Regulated Speed Compressor Installation

1 The compressor should be installed generally as instructed for a standard fixed speed compressor of the same power
(kW) rating. The installation should be completed by a CompAir authorised Distributor and must comply with
current wiring regulations.
2 Electrical circuit diagram 75688, for 15 kW RS models & 22kW RS models is attached for reference, see page 7
3 Electrical supply fuse sizes are the same as for standard fixed speed compressors of the same power (kW) rating.
Alternatively, a circuit breaker of suitable size and with motor starting characteristics may be used to protect the
installation. The maximum starting current under all starting conditions will not exceed 150% motor full load current and
will generally be no more than 100% full load current.
4 The installation must be earthed in accordance with local regulations. The use of RCD’s is not recommended.
5 Mechanical and pneumatic installation is as instructed for the standard fixed speed compressor of the same power (kW)
rating.
6 Water drain, filters or dryers fitted downstream of the compressor discharge must be correctly sized to avoid excessive
flow restrictions to ensure stable operation of the speed control system.
Also refer to Positioning of Pressure Transducer (below).

Compressor Operation

1 Apply electrical power to the compressor. When power is available the amber reset light ‘r’ will be illuminated, see the
control panel illustration Figure 1.
2 Press the green push button ‘1’. The amber light ‘r’ will extinguish and the speed control unit keypad display Figure 2 will
illuminate.
3 Rotate the compressor selector switch from position ‘0’ to position ‘1’, the compressor is now in running mode and will
commence rotation when the system pressure is below the target pressure.
4 During operation the compressor speed will vary automatically to suit flow requirements.
5 If air or gas demand reduces to a low level and the system pressure rises above the target pressure the speed control unit
will automatically stop the compressor after a short time delay; this saves even more energy. Re-starting will occur
automatically when the system pressure drops below the target pressure.
6 To manually stop the compressor, rotate the selector switch from position ‘1’ to position ‘0’. Do not operate the
emergency stop button unnecessarily.
7 During operation of the compressor the hours counter will register total running hours.

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CompAir Vane Regulated Speed (RS) Compressor

Fig 1 Control Panel

Pressure Control Adjustment

The RS compressor has default factory settings for speed control unit target pressure, compressor servo valve pressure, and motor
speed as follows: -

V15/22RS target pressure 8 bar, maximum speed 2030 rpm, minimum speed 990 rpm

The target pressure may be adjusted from the default setting in the range 6 bar to 10 bar for air compressors and 5.5 bar to 6.5
bar for natural gas compressors. When operating at other than factory set pressures adjustments to the compressor servo valve
pressure setting will be required.

Note: Natural gas compressors must not be operated above 7 bar in accordance with IGE regulations.

User Warning

The compressor settings, detailed below should not be attempted by the user and must be carried out by a CompAir
authorised service engineer, failure to comply with this requirement may invalidate the compressor warranty.

The inverter drive contains many control parameters that are collated into groups and sets, a number of these are used
to control the compressor. Certain parameters are available to “fine-tune” the unit to suit operational requirements. A
dedicated CP code list (Refer to page 6) is available to be viewed and/or adjusted using password security.

System Pressure Setting (Refer to figure 2)

The inverter control keypad is located in the left-hand side of the front trim panel positioned directly below the control panel
shown in Fig 1. Suitably authorised personnel can gain access by password for adjustments after removal of the central bolt in the
cover top face. If the Target pressure is to be changed from factory defaults (8bar), then only the compressor servo will need to
be adjusted, to approximately 1 bar above CP09. I.e. Target pressure @ 9 bar, servo to be set @ 10 bar.

On initial power-up the keypad defaults to ‘Actual speed value’ CP code 27.
Press the “FUNC/SPEED” button to display the code.
Press the down button repeatedly until CP code 9 is reached.
Press the “FUNC/SPEED” button to display the current pressure setting.
Press the up or down button repeatedly to reach the desired Target Pressure set point.

This leaves the menu open and therefore could be inadvertently adjusted.
It would be prudent to leave a “Display only” menu for security reasons.
Press the “FUNC/SPEED” button to reveal CP code 9.
Press the up button repeatedly until CP code 27 is reached.
Press the “FUNC/SPEED” button again to display the actual speed value.

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CompAir Vane Regulated Speed (RS) Compressor

Compressor Pressure Setting

For the adjusting procedure refer to Servo Valve Adjustment section in the Compressor User Handbook and the above User
Warning.

Notes:

1 A 12 bar (175 psi) pressure relief valve is fitted to all air compressor variants, this is to cater for the maximum pressure
setting of 10 bar, rising to 11 bar in offload condition.
2 An 8.6 bar (125 psi) pressure relief valve is fitted to all natural gas compressor variants, this is to cater for the maximum
pressure setting of 6 bar, rising to 7 bar in offload condition.
3 Each compressor is safe to operate at pressures up to the above maximums. The user must ensure that the maximum
operating pressure of all components of the compressed air or gas system are compatible with the maximum compressor
pressure setting.

Maximum Speed Settings

Maximum speed settings are configured automatically within the software to match the Target Pressure set point CP code 9. Speed
values for CP code 24 and CP code 25 are factory set and must not be adjusted.

Positioning of Pressure Transducer

1 The pressure transducer is located in the Minimum Pressure Valve Housing adjacent to the air or gas outlet from the
compressor; this position is suitable for the majority of installations.
2 If the air or gas pipework from the compressor to the system is restricted or prone to pressure fluctuation the pressure
transducer signal may create excessive response from the speed control unit leading to rapid speed changes and/or rapid
stopping and starting of the motor.
3 Should this condition occur re-locate the pressure transducer further downstream (e.g. to an air or gas manifold or ring
main) where restriction/pressure fluctuations are at a minimum.
4 If the installation includes an air or gas receiver, consideration should be given to piping the receiver pressure to the
transducer.

Continuous Running Option

If the flow demands of the system result in continual and rapid stopping and starting of the motor the compressor speed control unit
may be set to continuous running by removing link x52 & x53. (Refer to User Warning above.)

Note: If this option is selected the compressor will continue to operate under speed control achieving energy savings compared
with single speed compressor operating at part load.

Servicing

1 Service intervals and procedures are the same as specified for the standard fixed speed compressor of the same power
(kW) rating.
2 In addition to (1) the metal cover surrounding the speed control unit should be detached and any dirt or dust collected
around the control unit ventilator fan grille removed.
3 The speed control unit does not require any routine servicing.
4 After long operating periods (25,000 hours) the speed control unit capacitors and cooling fan(s) should be replaced to
ensure continued reliability of the unit.
5 A countdown mechanism using modulation hour recording (CP2) will trigger an LED visible warning at the appropriate
time.
6 Refer to CompAir Redditch Service Department for further details.

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CompAir Vane Regulated Speed (RS) Compressor

Operation with other CompAir Vane compressors.

Important Note

If the RS compressor is operated with other CompAir Vane standard single speed compressors feeding into a common
pressure system the maximum target pressure of the RS compressor must be limited to the (lowest) maximum pressure
of the single speed machine(s).

No attempt must be made to increase the operating pressure of the single speed machine(s).
1 CompAir RS compressors may be operated efficiently in conjunction with other CompAir vane compressors fitted with
automatic stop-start control.
2 Operation in conjunction with one other CompAir Vane compressor is simply achieved by adjusting the RS target
pressure to midway between the maximum and minimum pressure settings of the other compressor. The RS compressor
will automatically assume the lead compressor role.
3 The use of the CompAir ‘Smartbox’ is recommended when operating together with three or more CompAir Vane
compressors.

Fig 2 Speed Control Unit Keypad

Keypad

^
START
Up & Down ENTER FUNC
FUNC
F/R SPEED
Buttons STOP
SPEED
v

hydrovane

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CompAir Vane Regulated Speed (RS) Compressor

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