16 Chapter 3 Electrical Installation
Liebert APM 90 Integrated Modular UPS User Manual
Chapter 3
Electrical Installation
This chapter mainly introduces the electrical installation of the UPS, including the wiring of the power cables
and signal cables.
After completing the mechanical installation of the UPS, it is required to connect the power cables and control
cables of the UPS. All the control cables, whether shielded or not, shall be kept away from the power cables.
Warning: professional installation required
1. Do not apply electrical power to the UPS before being authorised to do so by the commissioning engineer.
2. The UPS shall be installed by a qualified engineer in accordance with the information contained in this chapter.
3.1
Wiring Of Power Cable
3.1.1
System Configuration
The cable size of the system power cable shall meet the following requirement:
UPS input cable
The cable size of the UPS input cable differs with the UPS power ratings and input AC voltages, provided that it
meets the requirement of maximum input current, including the maximum battery charge current, as shown
in Table 3-1.
UPS bypass and output cable
The cable size of the UPS bypass and output cable differs with the UPS power rating and output AC voltages,
provided that it meets the requirement of nominal output or bypass current, as shown in Table 3-1.
Battery cable
Each UPS connects to its battery through the positive, negative and neutral battery cables. The cable size of
the battery cable differs with the UPS power ratings, provided that it meets the battery discharge current
requirement when the battery discharges to near EOD voltage, as shown in Table 3-1.
3.1.2
Maximum Steady State AC And DC Currents
The power cable must be selected according to the current and voltage values in Table 3-1, the local wiring
regulations, the environmental conditions (temperature and physical media) and requirements in IEC60950-1
Table 3-B.
Table 3-1
Maximum steady state AC and DC currents
Rated current (A)
Busbar stud size
Output/bypass current
2
at full load
UPS rating
(kVA/kW)
Max.
input
current
1
380V
400V
415V
Positive/Negative
/Neutral Battery
discharge
current
3
at EOD
Input/battery
output/bypass
current
Recommen
ded torque
(N.m)
90/90 100/90 183
136 152 130
145
125
139
265/265/132
M8
12
72/72 80/72 145
109 121 104
116
100
111
213/213/106
M8
12
54/54 60/54 109
82 91 78
87
75
83
160/160/80
M8
12
36/36 40/36
72
54 61 52
58
50
55
106/106/53
M8
12
18/18 20/18
36
27 30 26
29
25
28
53/53/26
M8
12
