Emerson Liebert APS, User Manual

Page: 36 / 104

Installation
Liebert
®
APS
™
28
2.5.2 Transformer-Based UPS Cable Connection
A junction box is factory-installed on all models of the Liebert APS to ease cable connection.
Select the appropriate input cables according to
Table 5 and Table 6 based upon the UPS rating and
mains frequency. Emerson recommends sizing the frame’s overcurrent protection and wiring to
permit easier UPS system upgrades.
NOTE
After the output transformer is installed, if the startup is on bypass, the UPS has a six-cycle
inrush current that is up to 20 times the rated output current. This must be taken into account
when selecting the input overload protection device at the AC input supply distribution point.
To avoid random tripping on startup, Emerson
®
recommends that the AC input supply be
protected with a circuit breaker capable of withstanding this initial inrush (the MCB is
derated according to the D curve or TYPE 4).
This UPS is fitted with EMI filters. Earth leakage current is less than 40mA. Transient and
steady state earth leakage currents may occur when starting the UPS. This should be taken
into account when selecting transient RCCB or RCCD (leakage current devices of the UPS and
load).
The MCB of the AC power supply connected to the UPS input must bear this warning:
Disconnect the connection with UPS before maintaining this circuit
The warning is required because the UPS has no autofeeding protection device.
The UPS grounding should be in accordance with local regulations.
Table 5 Input cable selection for Transformer-based frames (60 Hz)
Maximum
System Rated
Load
Input Voltage - 200VAC Input Voltage - 208VAC Input Voltage - 240VAC
Maximum
Current in
UPS Mode
Recommended
Input Protection
Circuit Breaker
Maximum
Current in
UPS Mode
Recommended
Input Protection
Circuit Breaker
Maximum
Current in
UPS Mode
Recommended
Input Protection
Circuit Breaker
5kVA 27A 50A 26A 50A 23A 50A
10kVA 53A 70A 51A 70A 45A 70A
15kVA 80A 100A 77A 100A 67A 100A
20kVA 106A 125A 102A 125A 90A 125A
The power input and output terminals accept a maximum cable cross-sectional area of 70mm
2
(2/0AWG); the minimum cable
cross-sectional area is 16mm
2
(6AWG). The rated torque is 12.43Nm (110 in-lb).
90°C copper wire recommended.
Table 6 Input cable selection for Transformer-based frames (50 Hz)
Maximum
System Rated
Load
Input Voltage - 220VAC Input Voltage - 230VAC Input Voltage - 240VAC
Maximum
Current in
UPS Mode
Recommended
Input Protection
Circuit Breaker
Maximum
Current in
UPS Mode
Recommended
Input Protection
Circuit Breaker
Maximum
Current in
UPS Mode
Recommended
Input Protection
Circuit Breaker
5kVA 25A 63A 24A 63A 23A 63A
10kVA 49A 63A 47A 63A 45A 63A
15kVA 73A 100A 70A 100A 67A 100A
20kVA 97A 125A 93A 125A 90A 125A
The power input and output terminals accept a maximum cable cross-sectional area of is 70mm
2
(2/0AWG); the minimum cable
cross-sectional area is 16mm
2
(6AWG). The rated torque is 12.43Nm (110 in-lb).
90°C copper wire recommended.