Series IT

Innovation made in Ger ma ny

w w w . s c h a e f e r p o w e r . d e
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Inverters 1 or 3-Phase Output from 200VA to 45kVA, switchmode

AC
or AC
DC DC / AC Inverters, AC / AC Frequency Converters & Static Switches

■ Input voltage: 10-800V DC or

115/ 230V AC, single phase, 47-400Hz or
200/ 400/ 480V AC, three phase, 47-400Hz
■ Output voltage: 115/ 230 V AC, single phase
or 200/ 400/ 480V AC, three phases
■ Output frequency: 50/ 60/ 400/ 800Hz
(crystal stabilized) or programmable within
40-400Hz or 400-800Hz
■ Output power: 200VA - 45kVA

Features
■ Sine Wave
■ Continuous short circuit protection
■ Thermal shutdown with auto-restart for
1-phase inverters >1.2kVA
3-phase inverters >3.6kVA
■ Suitable for complex load
■ Surge power capability
■ Industrial grade components
■ Compact and robust design
■ 3-phase output: Unsymmetrical load permissible,
modular system with interchangeable inverters

Specifications Options

Input Output
Voltage range unit switches off at under- and Output voltages 115V AC 230V AC Input Monitoring
overvoltage 3x200VAC 3x400VAC 3x480VAC ■ Inrush current limiting for DC input of input / output voltage, current or frequency via
No-load input power 10 – 30 W or any other ■ Reverse polarity protection for DC input ■ analog signal
Inrush current for AC input and DC input >160V: Output power from 200 VA up to 45k VA ■ Autoranging for 115 / 230 VAC input ■ interface card RS232 or CAN Bus (external)
limited by thermistor Line regulation (±10%) 0.1 % for series CI, ■ Special circuit for 16.6Hz AC input
Hold-up time AC input: 10 ms typical 2 % for series IT and IV Programming
Series CI: 20ms typical 3 % for series IT and IV @ 400Hz Output of output voltage, current or frequency via
Immunity acc. to EN 61000-6-2 Load regulation (10-90%) 1 % typical, 3 % max.
■ Remote on / off (inhibit) ■ potentiometer
(400 Hz: 3 % typical, 5 % max.)
■ Static Switch (details see page 97) ■ analog signal
General Turn-on rise time soft-start, 100ms typical
■ Parallel operation for redundancy or increased power: ■ interface card RS232 or CAN Bus (external)
series IT5xxx
Efficiency 80 – 92 % Waveform sine wave or any wave shape pro-
Mechanics / environment:
Operating temperature – 20 to + 75°C grammable by external signal
Signals ■ 19” sub-rack for eurocassette, refer to page 121
optional: -40 to +75°C Frequency 40 – 800 Hz: adjustable or
via relay contacts ■ Wall mount
Load derating 2.5%/°C above + 55°C programmable or any fixed ■ Power ok (input) ■ Increased mechanical strength
Storage temperature -40 to + 85°C frequency (crystal stabilized) ■ AC ok (output) ■ Tropical protection
Cooling = natural convection Distortion 3 % typical, 5 % @ 400 Hz, ■ Extended temperature range to –40 °C
(details see page 131) = incl. temperature controlled fans 7 % @ 40 – 400 Hz, 800Hz ■ Temperature controlled fans for 19” units
Humidity up to 95 % RH, non-condensing Overload protection current limited to approx. 1.05 x
Safety / Construction acc. to EN 60950-1 / EN 50178 (steady state) nominal current
Protection category IP20 acc. to EN 60529, Surge power 2 x nominal power for 1 s
NEMA or others upon request Short circuit protection electronically limited to 3 x no-
EMI acc. to EN 61000-6-4, minal current, unit switches off
class A, optionally class B after 1 s
MTBF @40°C acc. to series IT: series CI: series IV: Crest factor approx. 3
MIL -HDBK-217E (notice1) 120.000h 70.000h 50.000h Power factor cos 0.7 inductive / capacitive
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Inverters 1 or 3-Phase Output from 200VA to 45kVA, switchmode

Series IT - Inverters with 1-phase output from 200 VA to 15 kVA Page 89

DC/AC Inverters
is a combination of a switch mode Inverter and a Transformer at the output. The
DC input AC output
transformer provides the isolation between input and output and transforms
Inverter Transformer
the voltage to the required level.

AC/AC Frequency Converters

is a combination of a switch mode Inverter with a rectifier at the input and
AC input AC output
a Transformer at the output. The transformer provides the isolation between
Inverter Transformer
input and output and transforms the voltage to the required level.

For lower input voltages the CI version is more compact than the IT version.

Series CI - Inverters with 1-phase output from 400 VA to 3.5 kVA Page 91

DC/AC Inverters
is a combination of a switch mode Converter and Inverter. The converter
DC input AC output
provides the isolation between input and output and transforms the voltage to
Converter Inverter
the level needed by the inverter for supplying the specified AC output voltage.

AC/AC Frequency Converters

is a combination of a switch mode Converter and Inverter. The converter
AC input AC output
provides the isolation between input and output and transforms the voltage to
Converter Inverter
the level needed by the inverter for supplying the specified AC output voltage.

Series IV - Inverters with 3-phase output from 600VA to 45 kVA Page 93

DC/AC or AC/AC
is a combination of 3 individual switch mode inverters with output transformers DC or
synchronized for a symmetrical 3-phase output. The transformers provide the AC input 3-phase
AC output
isolation between input and output and transform the voltages to the required
levels.
3 x Inverter 3 x Transformer

Series SS from 800 VA to 10 kVA Page 97

Static Switches
The Static Switch has two inputs for load supply, a priority and a non-priority AC supply 1
1-phase
input, and synchronizes the frequency of one supply to the other. Typically, but AC output
not exclusively, supplied by Mains & an Inverter, there are 3 modes of operation:
AC supply 2 static switch
1. Service mode Mains - mains is selected as the load provider.
2. Service mode Inverter - inverter is selected as the load provider.
3. Automated function with priority selection.

Series U from 1 to 2.5 kVA Page 99

UPS Systems with Static Switch

provides uninterrupted AC power to a critical load by connecting the load to AC mains
Static Switch Bypass Switch

AC output
AC supply 1 which can be the inverter output or to AC supply 2 which can (Load)

be the mains. Series U does not include the batteries. The batteries can be
specified and both, batteries and charger can be added to the system. =

Inverter

Battery

Connectors for Series CI, IT, IV & SS Page 132

Mechanics Series CI Series IT Series IV Series SS Series U

Eurocassette H15 & high currrent connector for I >50 A H15 and F24H7 -- H15 and F48 --
Wall mount or 19“ unit Terminals Terminals Terminals Terminals Terminals
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Inverters Series IT Switch mode inverter and transformer

DC input AC output m 22
Inverter Transformer DC / AC Inverters with 1-phase output from 200VA to 15kVA Size A 16
8m 0m
m
Size B 22
9m
m
22
0m
m

Cooling
Input VDC

6U
Output

6U
20 –32 Output 40 – 64 50 –80 Output 80 – 160 Output 160 – 320 340 –400 340 – 640 1) 450 –800 1) Output VAC
Size Size Size Size

360 mm
360 mm
VDC kVA VDC VDC kVA VDC kVA VDC VDC VDC VDC kVA
IT 1626 0.2 A IT 1636 IT 1646 0.4 A IT 1656 0.5 A IT 1676 IT 1686 Z 0.5 A
IT 3636 IT 3646 0.5 B IT 3656 1 B IT 3676 IT 3686 Z IT 3676 G 1 B
42
IT 3856 1.2 C IT 3876 IT 3886 Z IT 3876 G IT 3876 K 1.6 C TE mm 42 m
6.5 TE 6m
16 22
IT 4836 IT 4846 1.2 D IT 4856 2 D IT 4876 IT 4886 Z 2.5 D
Standard Optional Standard Optional
IT 4876 G IT 4876 K 2.5 D 115
IT 5636 IT 5646 2 E IT 5656 3 E IT 5676 IT 5686 Z IT 5676 G IT 5676 K 5 F + T1 Eurocassette / approx. 9 kg Wall mount / approx. 11 kg Eurocassette / approx. 11 - 13 kg Wall mount / approx. 13 - 15 kg
IT 5736 IT 5746 3 E IT 5756 5 F + T1 IT 5776 IT 5786 Z IT 5776 G IT 5776 K 8 F + T2
28 28
IT 5876 IT 5886 Z IT 5876 G IT 5876 K 10 F + T3 Size C m 0m
m Size D 9m
m 0m
m
9m 30
30
IT 5976 IT 5986 Z IT 5976 G IT 5976 K 15 F + T4
IT 1628 0.2 A IT 1638 IT 1648 0.4 A IT 1658 0.5 A IT 1678 IT 1688 Z 0.5 A
IT 3638 IT 3648 0.5 B IT 3658 1 B IT 3678 IT 3688 Z IT 3678 G 1 B

6U

6U

360 mm
360 mm
IT 3858 1.2 C IT 3878 IT 3888 Z IT 3878 G IT 3878 K 1.6 C
IT 4838 IT 4848 1.2 D IT 4858 2 D IT 4878 IT 4888 Z 2.5 D
IT 4878 G IT 4878 K 2.5 D 230
m
IT 5638 IT 5648 2 E IT 5658 3 E IT 5678 IT 5688 Z IT 5678 G IT 5678 K 5 F + T1 56
TE 6m 56 m
30 TE 6m
IT 5738 IT 5748 3 E IT 5758 5 F + T1 IT 5778 IT 5788 Z IT 5778 G IT 5778 K 8 F + T2 30

IT 5878 IT 5888 Z IT 5878 G IT 5878 K 10 F + T3 Standard Optional Standard Optional

IT 5978 IT 5988 Z IT 5978 G IT 5978 K 15 F + T4 Eurocassette / approx. 16 - 18 kg Wall mount / approx. 19 - 21 kg Eurocassette / approx. 18 - 24 kg Wall mount / approx. 21 - 27 kg
= natural convection = incl. temperature controlled fans 1)
standard version: wall mount
m
0m 50
0m
m
Size E 31 0m
Size F 31 50
m 0m
m

6U
6U
AC input AC output

400 mm
600 mm
Inverter Transformer AC / AC Frequency Converters with 1-phase output from 500VA to 15kVA
19 m
" 0m 19
46 " m
Input VAC Input VAC Input VAC 0m
36
Cooling

1-Phase Output 1-Phase 3-Phase Output Output

Size Size Standard Optional Standard Optional
kVA + 15 % + 15 % + 15 % + 10 % kVA VAC
115 ± 20 % 230 – 20 % 3x200 – 20 % 3x400 – 20 % 3x480 – 15 % 19“ Plug-in module / approx. 46 - 50 kg Wall mount / approx. 54 - 58 kg 19“ Plug-in module / approx. 32 kg Wall mount / approx. 36 kg
IT 1666 0.5 A IT 1686 IT 1666 V 0.5 A
IT 3666 1 B IT 3686 Size L
IT 3666 V IT 3686 V 1 B
IT 3866 1.2 C IT 3886 IT 3866 V IT 3886 V IT 3896 V 1.6 C
IT 4866 2 D IT 4886 IT 4866 V IT 4886 V IT 4896 V 2.5 D
115
IT 5666 3 E IT 5686 IT 5666 V IT 5686 V IT 5696 V 5 F + T1

3HE
IT 5766 5 F + T1 IT 5786 IT 5766 V IT 5786 V IT 5796 V 8 F + T2 19“, 3U high packages:
available for series IT16xx up to IT36xx.
IT 5886 V IT 5896 V 12 F + T3
IT 5986 V IT 5996 V 15 F + T4
19
"
IT 1668 0.5 A IT 1688 IT 1668 V 0.5 A 2m
m = incl. temperature controlled fans
36
IT 3668 1 B IT 3688 IT 3668 V IT 3688 V 1 B
IT 3868 1.2 C IT 3888 IT 3868 V IT 3888 V IT 3898 V 1.6 C Optional
IT 4868 2 D IT 4888 IT 4868 V IT 4888 V IT 4898 V 2.5 D 19“, 3U Plug-in module
230
IT 5668 3 E IT 5688 IT 5668 V IT 5688 V IT 5698 V 5 F + T1
IT 5768 5 F + T1 IT 5788 IT 5768 V IT 5788 V IT 5798 V 8 F + T2 W
IT 5888 V IT 5898 V 12 F + T3 = natural convection D Size T1 - T4 Size T1
IT 5988 V IT 5998 V 15 F + T4 = incl. temperature controlled fans
Trans- H W D Weight Trans- H W D Weight
former in mm in kg former in mm in kg

H
H
Frequency Designation T1 390 240 233 33 T1 335 230 210 33
T2 450 280 253 50
.1 40 - 400 Hz adjustable / programmable T3 450 280 283 66 Transformers refer to 50/60 Hz.
.2 45 - 65 Hz adjustable / programmable T4 500 320 280 110 Other frequencies or tropical insulation may
.3 any fixed frequency between 40 - 400 Hz W change size and weight.
D
.4 400 Hz Transformers refer to 50/60 Hz.
.41 synchronized with 400 Hz mains Standing version Other frequencies or tropical insulation may Wall mount version
.5 50 Hz change size and weight.
.51 synchronized with 50 Hz mains
.6 60 Hz
.61 synchronized with 60 Hz mains
.7 50/60 Hz switchable
.8 800 Hz
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Options & Accessories for Switch Mode Units

Schaefer offers the industry’s most

complete range of input and output
voltages, combined with a selection
of package style, mounting solutions,
options for input and output as well as
various possibilities of programming &
monitoring.

Configuration of model designation:

Add the designation of options to
the type number of the power supply
module, e.g. C 3674-w-dr-eu1.

Input

i inrush current limiting ad reverse polarity protection for DC input by anti parallel diode
A thermistor is connected in series with the input lines which changes its resistance from To avoid the power losses a diode is provided with opposite polarity in parallel to the
high to low when it gets hot. It does not reduce the surge current if the input power input blowing an internal or external fuse if the module is connected to a supply of wrong
is interrupted for a short period of time not allowing the thermistor to cool down. IN OUT
polarity. IN OUT
Thermistors are fitted as standard to all mains input models except for 1-phase input calculation formula: IDiode= 2 x Pout max / Uin min
of models > 2.5 kW. Thermistors are available up to 45A. For higher input current an
electronic inrush current limitation can be offered. au auto-ranging
ie electronic inrush current limiting For standard dual AC input models the range of 115 / 230 V AC is to be selected by L
An electronic circuit limits the high inrush current caused by built-in capacitors. Switch- connecting the input line to different pins on the connector. With auto-ranging the unit
115V AC
on time may increase to 5s. senses the input voltage and provides automatically the correct connection. or OUT
230V AC
This is realized by a series pass transistor or depending on the input voltage by thyristor IN time OUT
delayed N
softstart.

sd reverse polarity protection for DC input by series diode

A series diode protects the module against DC input voltage of wrong polarity. However,
this also causes extra losses and reduces the overall efficiency.
calculation formula: IDiode= 2 x Pout max / Uin min IN OUT
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Options & Accessories for Switch Mode Units

Output

Parallel / redundant operation for DC output (details see page 125/126) Inhibit
dd decoupling diode h1 inhibit by external closing contact, signal referred to input
A series diode built into the units output allows paralleling of 2 or more units for The operation of the unit is inhibited when a voltage signal is applied in reference to the
redundancy or higher power or battery charging. For control purposes the anode of the negative line of the input. This can also be used in combination with a thermal trip, which primary
primary
+
diode is also available at the output connector. It cannot be loaded ≥ 0.5A. The sense shuts the unit down. IN control
control OUT
INH
signal is taken partially from the anode and partially from the load/cathode of the IN OUT
decoupling diode. This guarantees starting and operating under all conditions, but it -
also effects the regulation accuracy of 2%. In this way it gives a load sharing of 15-30%
h2 inhibit by voltage signal, signal referred to output
between the paralleled units.
Operation of the unit is inhibited if a voltage signal (5V / 10mA) is applied in reference to
cs active current sharing the negative line of the output. sec.
secondary
An additional control circuit provides active current sharing via an interconnecting wire control
control
IN INH
IN
between converters that operate in parallel. The output lines of the converters have to be
CS +
in “star point” connection. OUT -

h3 inhibit by closing contact, signal referred to output

IN
CS The operation of the unit is inhibited when a voltage signal is applied in reference to the
csi current sharing interrupt (“cs” included) negative line of the output. This can also be used in combination with a thermal trip, sec.
secondary
which shuts the unit down. IN
control
control INH
“csi” will effect the removal of the “cs” signal from the load voltage common connection.
Please note: Only relevant solution for inverters.
Should there be an instance where a unit is not supplying the load, then the effect of its IN
CSI
current sharing signal is removed, and the load voltage is unaffected by this condition. In OUT
+
-
terms of calibration the same criteria follow as for parallel operation.
IN
CSI Automatic reduction of current limiting

icsi current sharing interrupt (“csi” included), galvanically isolated rco reducing current limiting at over temperature

The inclusion of “csi” (current sharing interrupt) and the galvanic isolation is the optimum A circuit reduces the current limiting level at higher temperature (to be specified).
set up for systems with high power or high currents, were the voltage drop on the power IN
CSI
IV sec.
secondary
wiring could influence the cs signal. Please note: IN
control
control
RCO OUT

OUT Option is avalaible for series 48xx with ZVS topology and for high power converter
modules (see page 49).
IN CSI
IV

ma master / slave operation (avalaible for series 6xxx)

Master / Slave interface permits the parallel function of identical modules to increase the DC output protection
MS
output power capapcity, shared by current control without any dynamic reduction in IN current
current
regulation
rd reverse polarity protection for DC output
regulation

performance. by reverse diode with external fuse

OUT
SL
IN current
current IN OUT
regulation
regulation

Parallel / redundant operation for AC output

red inverter parallel operation: for series IT5xxx
For redundant operation or for increased output power, two inverters of the IT5xxx series
OUT
can be switched together. If one inverter fails, the internal contactor will be switched off IN current
current
sharing
sharing
L
and the output power of one inverter is still available.
N

IN OUT
current
current
sharing
sharing

General information

The number of options per module may be restricted due to limitation of space inside the module or due to a limited number of
connector pins. Potentiometers or interface cards may be supplied separately for installation outside of the module.
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Options & Accessories for Switch Mode Units

Signals Programming

pr input voltage supervision (power ok) incl. relay contacts Converter Programming Charger Programming
A logic signal is given if the input voltage (AC or DC) drops below the specified limit. In programming of output voltage from 0 to 100 % temperature features
AC input models the rectified input voltage is sensed so that a power fail alarm can be eu1 by external signal, 0 – 10 V tc temperature compensated charging voltage
avoided if at light load mains power returns before the input capacitors are substantially IN OUT
eu2 by external signal, 4 – 20 mA (sensor not included)
discharged. A relay contact is provided for failure indication.
eu3 by 270° potentiometer ts1 temperature sensor not interchangeable due to fixed
eu4 resistor values
dr output voltage supervision (DC ok) incl. relay contacts by 10 turn potentiometer
ts2 temperature sensor interchangeable, IC controlled
A logic signal is given if the output voltage is below the specified limit. A relay contact is programming of output current from 0 to 100 %
+
provided for failure indication. ei1 by external signal, 0 – 10 V charging characteristics
DC ok level: 5V output: 4,75V IN OUT ch1 External card: automatic and manual selection of charging
ei2 by external signal, 4 – 20 mA
all other voltages: 90% of adjusted voltage - characteristic (float/ equalized boost charge) with timer
ei3 by 270° potentiometer (delayed return to normal operation), including aux.
cf charger / converter fail supervision incl. relay contacts ei4 by 10 turn potentiometer supply and options “tc” and “ts1”
A logic signal is given if the input voltage, the auxiliary voltage of the primary side and iso isolating amplifier for programming ch2 External card: consisting of option “ch1” plus: Battery
the current of the primary side exceed or go below a specified range. A relay contact is primary Programming signal is galvanically isolated from any current limitation & battery shunt
control supervision
provided for failure indication. IN circuit OUT potentials of the power supply. ch3 External card: consisting of option “ch2” plus: CAN-Bus-
programming via interface & programmable parameters
rs RS232 (external)
ac AC ok for inverter including relay contacts
can CAN Bus (external)
A logic signal is given if the output voltage of an inverter is below the specified limit. A
L
relay contact is provided for failure indication.
IN

Monitoring

Converter / Charger Monitoring

monitoring of output voltage from 0 to 100 %
mu1 by external signal, 0 – 10 V
mu2 by external signal, 4 – 20 mA
monitoring of output current from 0 to 100 %
mi1 by external signal, 0 – 10 V
mi2 by external signal, 4 – 20 mA
iso isolating amplifier for monitoring
Monitoring signal is galvanically isolated from any
potentials of the power supply.
monitoring via
rs RS232 (external)
can CAN Bus (external)

General information

The number of options per module may be restricted due to limitation of space inside the module or due to a limited number of
connector pins. Potentiometers or interface cards may be supplied separately for installation outside of the module.
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Options & Accessories for Switch Mode Units

Mechanics Environment

t tropical protection
As standard, all of the modules are designed and manufactured for insertion into 19”
The unit is given additional protection by a heavy coat of varnish on the printed circuit board(s) and on components to achieve 99%
sub-racks. Higher power modules are already constructed in 19” format.
RH, non condensing.
Optionally, 19” sub-racks are available and can be configured as 3U or 6U allowing any c extended temperature range
mix of units and can be upgraded in accordance to the customers’ requirements, e.g. The circuit is designed and tested for operation at an ambient temperature as low as – 40°C.
ms increased mechanical strength
■ mating connectors wired to a terminal block
■ fuses or circuit breakers Screws are secured with Loctite and heavy components are fastened by ties and / or glue. Modules with the „ms“ are build acc. to
■ hot swappable configuration upon request EN 61373 regarding shock and vibration.
■ analog or digital meters
■ switches
■ fans
■ filters
■ decoupling diodes
■ provisions for keying the modules to ensure module / slot designation

19“ Sub-Racks
19" = 483 mm 19" = 483 mm

3U = 132.5 mm
2TE = 10 mm
6U = 266 mm

6U = 266 mm
19" = 483 mm
3U = 132.5 mm

3U = 132.5 mm
84TE = 426.7 mm 84TE = 426.7 mm 84TE = 426.7 mm

w wall mount
Modules, which have the wall mount option, are typically fixed
to a structure or within a cabinet. Depending on the size of the
module, this may be done with a flat or angled plate (see pho-
to). The load connections are typically through a terminal block.
Should the application not require a pluggable module / rack
solution, wall mounting presents an alternative option for the
customer to choose from.

cha chassis mount

Module is designed for installation to a structure or within a cabi-
net. Screw type mating connectors are supplied with the module.
Due to the limited number of connector pins this option is not
available for modules with dual AC input. Option is avalaible for
currents up to 60Amps.

din DIN rail mount

Module is designed for DIN rail mounting to a structure or within
a cabinet. Screw type mating connectors are supplied with the
module. Due to the limited number of connector pins this option
is not available for modules with dual AC input. Option is avalai-
ble for currents up to 60Amps.
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Options & Accessories for Switch Mode & Thyristor-Controlled Systems

Control & Monitoring

TC 01 Control function
analogue or micro-processor-controlled supervision:
■ input voltage

■ output voltage

■ battery circuit

■ ground insulation failure

■ over temperature

UC 03 Inhanced controller function

The „UC 03“ unit controls and supervises the optimum charging
of a battery, up to an entire UPS system. A battery charging in a
basic way, with a switch mode AC / DC or DC / DC Charger, is
shown in the following figure.

Mains Power

UC 03-xx Charger
V ref V o/p

0...10V =

Battery current
Battery voltage

Battery

The charger output voltage is regulated inside the charger accor-

ding to the input “Vref” signal. The gain factor between Vref and
Vo/p is defined in the Specification of the Charger. The charger
current limitation is also a function of the charger. The reference
values, limitations and monitoring levels for charging a battery
(ies) are configurable in the UC 03. The charging of the battery
occurs according to the current / voltage characteristics, i.e. the
battery is loaded in current limitation, until the appropriate vol-
tage is reached. The following working conditions are processed
by the UC 03:
a.
Float Charge conforms to the recommended permanent voltage
to hold the battery within a completely charged state.
b.
Equalize or Automatic Boost Charge: To charge the battery after a
partial or deep discharge as quickly as possible, an increased vol-
tage is provided. This mode is activated automatically via different
functions, or manually via the front panel button.
c.
Manual Boost Charge: independently adjustable voltage, to rege-
nerate an aged battery. In all three working conditions the maxi-
mum battery charge current is limited.
 www.schaeferpower.de
Technical Notes Operational Characteristics

The following technical notes contain impor-

tant information about various operating pos-
sibilities and circuitries as well as instructions
that should be followed during installation
etc. For further information please contact the
SCHAEFR Team.

Parallel / Redundant System 125

AC or DC input 127
DC output 128
AC output 129
DC output voltage stabilization 130
Mounting & Installation 131
Connectors 132
Basic Topologies 133

Parallel / Redundant System

Parallel operation Balanced current operation

Single output modules of the same voltage / power rating DC or The inclusion of the option “cs” (current sharing) allows DC or
can operate in parallel under specific conditions. The output AC for parallel operation with a significant degree of current AC
= =CS
voltage can be carefully adjusted to be near identical. When balancing. The communication between the units allows for
CS
there is sufficient loading on the combined output, all units a voltage setting correction, which in turn shall equate to an
will be active and supply the load. The load demand must automatic current sharing (balancing) on the outputs. The
DC or DC or
be significant enough for the multiple units to deliver output AC tolerance of such balancing is module dependent. In terms of AC
current. = calibration the same criteria follow as for parallel operation.
=CS
Redundant operation
Redundant balanced operation
The inclusion of the option “dd” (decoupling diode) on the
DC or The inclusion of both, the “cs” and “dd” option results in an
output of the units will permit parallel operation, where AC
DC or
optimized balanced current provision while being de-coupled AC
the inability to provide output from one unit will not have = from each other. A connected module, who is not supplying
=CS
a negative effect on the load provision. The decoupling CS
an output voltage, will influence the load voltage. The voltage
diode will also result in a load regulation value, which, as
may be reduced by up to 7 %. In terms of calibration the same
a percentage of the output voltage, will be unit / output DC or
DC or
AC criteria follow as for parallel operation.
dependent. In terms of calibration the same criteria follow as = AC
=CS
for parallel operation.

Fault tolerant operation

The inclusion of “csi” (current sharing interrupt), “cs” and DC or
“dd” is the optimum set up for a fault tolerant application. AC
CSi
“csi” will effect the removal of the “cs” signal from the load = CS
voltage common connection. Should there be an instance CS

where a unit is not supplying the load, then the effect of its
DC or
current sharing signal is removed, and the load voltage is AC
CSi
unaffected by this condition. In terms of calibration the same = CS
criteria follow as for parallel operation.
 www.schaeferpower.de
Technical Notes Operational Characteristics

AC or DC input DC output

inrush current Soft start

When the module is connected to the input power, the short period of time not allowing the thermistor to cool The application of the input power permits the unit to a controlled charging of the secondary capacitors. The time
primary capacitors will be charged by a high current pulse. The down, and the primary capacitors are discharged, the current generate a secondary output. The switching on of the primary duration for the secondary capacitors to be charged is defined
magnitude of this pulse depends mainly on the input supply limitation function of the thermistor will not be effective. The power circuit is controlled and gradually increased to allow as the soft start.
system. With a thermistor (temperature dependent resistor) thermistor is standard on mains input models up to 45 Amps
No load operation
in series with the input, this current pulse can be reduced, input current. For higher input current there are two further
Single output converters require no minimum load for the main output be loaded. Semi-regulated auxiliary outputs
as the thermistor has a relatively high value of resistance as alternatives available: Schaefer PFC or an electronic current
operation within tolerance. Multi output converters require may also require a minimum load to be applied.
long as it is cold. This resistance becomes very low as the limitation.
thermistor heats up. If the input power is interrupted for a Short circuit protection
Power factor correction (PFC) The main output of a converter will be immune against removal of the overload / short circuit will result in the output
Power supplies draw line current in pulses from the input the AC input supply. The result of this integration, be it active a momentary or continuous short circuit. The secondary voltage being increased to the calibrated value. Regulated
supply. Should it be required, a PFC will integrate these pulses or passive, is the reduction of the harmonic distortion and current limitation will not permit the sustained output current auxiliary outputs will also reduce the output voltage / current
to be both, effectively sinusoidal in shape, and in phase with allows a more effective loading of the input source. to be higher than the calibrated setting, and it will actively in accordance to their overloading. The characteristic may
reduce the output voltage in accordance to the overload. The vary according to the circuit employed.
Spike suppression
Over voltage protection (OVP)
High input voltage spikes generated in the supply system that absorbed by a varistor across the input lines.
The main output voltage is measured, either internally or value, the primary power circuit is permitted, once again, to
could disturb operation of the unit or cause damage will be
through sense leads. This measured value is compared be activated. The high power units have an additional feature,
Input under and over voltage turn off against a calibrated value. When the calibrated value has which will shut down the primary power circuit after a
The input voltage range of the unit is defined as the voltage voltage. Once a preset value is reached then the power circuit been reached, this circuit turns off the primary power circuit. continued OVP operation. The input power must be re-cycled
limits at which it will operate. Should the input be reduced to will be switched off. It must be considered that the switching Once the measured value has reduced below the calibrated in order to remove the unit from shut down.
a specific voltage, the unit will turn off by switching off the off of the power circuit does not mean a removal of the input voltage adjustment [V] 5 9 12 15 24 28 48 60 110 200 220 400
power circuit. The same applies to an increase in the input circuit from the power supply.
Over voltage protection [V] 6.5 12 15 18 30 35 60 70 140 220 280 440
Thermal shutdown with auto restart
Sense leads
The higher power Schaefer modules are fitted with a thermal remain active until the point of temperature measurement has
Through the use of sense leads, an output voltage may be voltages to. Units whose output voltage has been calibrated
shutdown. In the event of a temperature rise above a preset reduced significantly. The time duration for this to be reached
regulated to a point outside of the unit. The sense leads should to be near identical will now be able to supply a common
value, the unit will turn off. This safety feature will then is dependent upon the environment and level of cooling.
be connected to the power connection at the point of load load.
Temperature derated load under regard of polarity. There should be a non-interruptible De-coupled outputs will be sensed both, before and after the
It is the responsibility of the client to reduce the loading of the maximum operating temperature of +75 °C must lead to the connection between sense and load points. Interruption decoupling diodes, which in turn will lead to an output
Schaefer product with respect to the temperature (derated unit being switched off. may lead to damage or the activation of the OVP circuit. The voltage regulation, specifi c to load and unit. Sense leads
load: 2.5 % / °C from +55 °C operating temperature). The units, which have sense leads, have the ability to regulate to are typically employed with a decoupled output voltage of
a higher voltage at the output connection. This increase is less than 40 VDC. The current sharing option will effectively
Efficiency largely dependent upon the unit. The details may be found in override the sense lead output voltage setting, but the point
The optimum efficiency is obtained through a high input power rating. the respective unit specification. Parallel operation with sense at which the output voltage is regulated, will be the point of
voltage measured against a high output voltage at maximum leads allows a common point for the units to regulate their sense lead connection.

- -S +S +

- +
LOAD
 www.schaeferpower.de
Technical Notes Operational Characteristics

AC output DC output voltage stabilization

Soft start The output voltage of a battery charger with parallel

The application of the input power permits the unit to output generation until the nominal value is defined as the connected batteries varies substantially with the
generate an AC output. The output power increases linearly soft start. charging condition of the battery. For many applications,
until it reaches its calibrated value. This delay from initial however, the load circuit requires a more stabilized
voltage which can be accomplished by:
No load operation
Voltage dropping diodes
Inverters require no minimum load for operation within tolerance.
being interconnected between battery and load, reduce
Short circuit protection the voltage to a value suitable for the load. They are
The inverter current limitation circuit provides a protection will then be reduced to typically 105% of the nominal value. short-circuited by one or more contactors only if a partial
against an external short circuit. Due to the need for crest Should the overloading persist, and the output voltage reduce reduction or no voltage reduction is required. A control
factor and pulse power requirement in many applications, the to less than 20% of nominal, then the unit will perceive an circuit senses the battery voltage and energizes the
current limitation permits twice the nominal output current overload condition and turn off. Recycling the input voltage contactors. Voltage dropping diodes cause substantial
to be extracted for up to 1 second. The current limitation will remove this latched off condition. power losses as the excess voltage is absorbed by the
diodes. However, due to simplicity, this method is
Crest factor
frequently used, especially if the voltage reduction
The ability of an inverter to deliver to a load an inrush current between the nominal and the peak current. is needed only during the short periods of high-rate
is related to the crest factor. The crest factor is the ratio charging.
Over voltage protection (OVP) AC input
The high power units have this feature. It will shut down the When the reference value has been reached, this circuit turns
primary power circuit after a continued OVP operation. The off the power circuit. Once the measured value has reduced
battery
input power must be re-cycled in order to remove the unit below the reference value the power circuit is once again charger
from shut down. The output voltage is measured internally. permitted to be activated.
This measured value is compared against a reference value.

Sense leads
Sense leads are internally connected in all standard configurations. K2
control
circuit
Harmonic distortion for
K1 and K2
The generated inverter output is designed to follow a true distortion. The total harmonic distortion THD is the
sine wave signal. Deviation from this sine wave is measured relationship between the harmonic and fundamental wave K1

as distortion. The level of deviation is defined as harmonic forms.

Surge power - +
The AC output may facilitate the output load through its second. battery DC-load
ability to provide more then the nominal current for up to 1
Switchmode step-up converters
Power factor
are DC/DC converters supplied from the battery with the
The AC output may facilitate complex or other loads, through more than the nominal output current for a limited period of output connected in series to the battery. They present a
its ability to provide a phase shifted output current at nominal time. very economical solution as they only add voltage when
power rating. This is once again due to the ability to provide the battery is discharged. Details see page 47/ 83.

step-up converter (long) cable to load

+

battery -
charger
load
sense leads
+

-
 www.schaeferpower.de
Technical Notes Mounting & Installation

Mounting Connectors

Air flow H15 Female Connector

Airflow to the power supply is preferred to be filtered, below 55°C, an airflow resistivity Number of contacts: 15
(pressure drop) of below 20kPa and is required to comply with the EN60950 pollution Contacts: Fastons or screw terminals
category II. Diffused thermal energy is required to be exhausted and displaced by air as Operating current at +20 °C: 15 A

AIR FLOW
detailed above. Thermal management is required where the air provided to a power Operating temperature: – 55 to +125 °C
supply complies with the power supply’s design parameters. The use of fans requires the Test voltage (contact to contact): 3100 Vrms
increase airflow rate to a minimum of 120m3/h (corresponding to 70 cfm). The airflow Test voltage (contact to ground): 3100 Vrms
resistivity and respective pressure drop should be considered when the fan is required. Contact resistance: 8 mΩ
Direction of air flow Performance according to: IEC 60603-2 / DIN 41612

Typically, Schaefer Modules and systems are cooled through air supply entering below
and exiting above, with the exception of models of series C/B 5100, 5200, 5300, 5400, High Current Female Connector
W
FLO
6400 and 6600 whose airflow is from front to back. AIR Number of contacts: 2
Contacts: Bolts with 8 mm diameter for terminal lugs M8
Custom design also offers lateral cooling. Such details are however, project specific. Operating current at +20°C: 170 A
Operating temperature: –55 to +125 °C
W
Test voltage (contact to contact): 500 Vrms
FLO
AIR Test voltage (contact to ground): 2500 Vrms
Cabinet Contact resistance: 0.06 mΩ
Dimensions (H x W x D): 118 x 35 x 85 mm
To enhance a module / system, a cabinet may be employed.
Performance according to: IEC 60603-2 / DIN 41612
- This may be required to fulfil the increased IP / NEMA rating, due to a negative effect of
the environment on the solution. F24H7 Female Connector
- Specifically, in an unclean, saturated, corrosive or otherwise aggressive air quality it Number of contacts: 24 / 7
may be required to employ a cabinet in combination with features such as hermetical Contacts: solder pins / fastons
closure and air exchange amongst others. Operating current at +20°C: 6 / 15 A
- The enclosure must be capable of sustaining the weight of the modules, specifically if Operating temperature: – 55 to +125 °C
module support rails are used. Test voltage (contact to contact): 1550 / 3100 Vrms
- Stationary cabinets should be fastened to the ground. Test voltage (contact to ground): 2500 / 3100 Vrms
- The centre of gravity must be as low as possible with portable systems. Contact resistance: 15 / 8 mΩ
Transportation of module Performance according to: IEC 60603-2 / DIN 41612

The grips on the front of the modules are to assist in module insertion into a sub-rack,
and not for supporting the weight of the module. F48 Female Connector
Number of contacts: 48
Wall mount / chassis mount
Contacts: solder pins
Modules with a mounting plate or angle are designed for integration into the host Operating current at +20 °C: 6A
equipment. They are not for employment outside of an enclosure. Operating temperature: – 55 to +125 °C
Test voltage (contact to contact): 1550 Vrms
Test voltage (contact to ground): 2500 Vrms
Contact resistance: 15 mΩ
Performance according to: IEC 60603-2 / DIN 41612
Installation

Input fuse
An input fuse, internal or external, should be selected with a slow burn characteristic.
Sense leads
- The distance between the load connection and the module / system may result in a
voltage drop between the output and the load connection. To compensate for a limited
value of such a voltage drop, sense leads can be connected to the load under regard
of polarity. The sense leads determine the point to which the voltage regulates. As the
sense leads carry very low current, they are susceptible to noise pick up. Therefore, it is
recommended that they are intertwined and if necessary shielded. - -S +S + - -S +S +

- When the remote sense facility is not used, sense links must be made at the output
terminals. If the sense links are left open, the output voltage may rise causing the OVP
circuit to be activated.

- + - +
LOAD LOAD
 www.schaeferpower.de
Technical Notes Basic Topologies

There are various circuit topologies and the selection depends on the requirements, such as low or high input voltage, low or high output Full Bridge Converter with Zero Voltage Switching (ZVS)
voltage, single or multi output, power rating. The following circuits present our common concepts of power conversion.
For the higher power modules presented from page 46 to 67 the error signal controls via opto-coupler the switching transis-
the primary circuit is performed as a full bridge connection tors on the primary side. For over voltage protection the OVP
Push Pull Converter with four switching transistors (IGBTs) being controlled by the circuit senses the output voltage and turns off the switching
driver and protective circuits. The special mode of driving the transistors if a certain level is reached. The circuit automatically
The push pull converter is often used ripple IGBTs in conjunction with the resonant choke and the symmet- returns to operation but is repeatedly switched off and turned
for applications with low input voltage. filter
+ rical capacitor allows for “zero voltage switching” which im- on again if the over voltage condition is still present. If the unit
The switching transistors are alternately
RFI output proves the efficiency and reduces the switching noise. The in- does not return to normal operation within a short period of
conducting with variable pulse-width. At the +
filter
- put can be designed for both, DC or AC. At the secondary side time, it will then be switched off. For current limiting the signal
secondary side, after rectification and filtering,
DC
I-lim. OVP of the transformer the voltage is rectified and filtered. Then the sensed by the LEM transformer starts to reduce the output volt-
the output voltage is sensed and compared input output voltage is sensed and compared with a reference, and age if the current exceeds a certain limit.
with a reference. The error signal controls via -
an opto-coupler the primary circuit. I-lim. opto- +
sense RFI filter ripple filter
couplers - +
+
prim.control sec.control
IGBTs
Half Bridge Converter
The following circuit shows, as an example, a resonant
RFI choke
converter with dual AC input in a half bridge filter ripple DC input DC output
filter +
connection. With the input voltage supplied 115V AC

to the 230 V terminal, the rectifier circuit is a 230V AC main LEM

output transformer
standard bridge connection; supplied to the 0V - -
-
symmetrical
115 V terminal the rectifier circuit functions as AC input I-lim. OVP
capacitor
a voltage doubler circuit. - rect. OVP
I-lim.
sense
opto- +
opto- +
sense
couplers -
prim.control sec.control coupler control -

DC/AC Inverter Driver

and protective
The diagram beside shows the circuit of an circuits for IGBTs
inverter. The DC input voltage is transformed
by the power transistors T1-T4 with the parallel
control + PWM
connected inverse diodes D1-D4 in a pulse- T1 T3
D1 D3
width modulated square wave voltage. The
choke with the windings LI and LII integrates
opto- opto-
this voltage, and at the capacitor C a sinusoidal Inverter coupler coupler
output voltage is available. The power DC input
voltage
transistors are controlled via opto-coupler in sense
T2 T4
such a way that not both transistors of one D2 D4
current
branch are conducting at the same time. The sense
output voltage is sensed and compared with
a reference signal generating the firing pulses R2 LI C LII
for the power transistors. The output current
is measured via shunt R1 and limited through
the control circuit. Isolation between input
R1
and output and voltage transformation can
either be provided by a converter connected Inverter AC output
to the input of an inverter or by a transformer
connected to the output of an inverter.