Critical Power
Modifications reserved
Page 21/46
GE_UPS_OPM_SGS_ISG_10K_40K_0US_V070.docx
Installation Guide
SG Series 10-20-30-40 UL S
3.7.3
Battery over current protection and wire sizing
Please read the safety precautions at the front of this guide carefully, and thoroughly review the
battery manufacturers installation and maintenance manual before connecting the batteries to the
UPS.
If the UPS system has been purchased with an accompanying battery cabinet, that cabinet should
have an integral battery circuit breaker.
If the UPS has been purchased without a battery cabinet or remote rack mounted batteries are to
be used then DC over current protection must be provided by others.
Choose an appropriate DC fuse or circuit breaker using the current data in the chart below.
Minimum battery cable requirement is based on the current data below.
The AC values below are current ratings per phase.
These maximum and nominal ratings should be considered when choosing the appropriate AC
over current protection device.
NEC (National Electric Code) Section 210-20 a rules must be applied.
DC current rating is the nominal battery discharge current which the UPS allows.
(See
Fig. 3.7.1-1
and
3.7.1.2
)
UPS rating
AC Input Rectifier
AC Input
Bypass
AC Input
DC Input
F1
F2
F3
F4
Nom.
Max.
Nom.
Max.
SG Series 10
17.2 A
20.2 A
12 A
17.2 A
20.2 A
19.6 A
SG Series 20
27.3 A
36.6 A
24.1 A
27.3 A
36.6 A
36 A
SG Series 30
40.4 A
53.1 A
36.1 A
40.4 A
53.1 A
55.2 A
SG Series 40
53.9 A
63.2 A
48.2 A
53.9 A
63.2 A
76 A
Size of Branch Circuit Over current Protection - All Models: - "CAUTION - To reduce the risk of fire,
only connect UPS to a circuit provided with (See below) maximum amperes branch circuit over
current protection in accordance
with the NEC (National Electric Code), NSI / NFPA 70
UPS rating
AC Input Rectifier
AC Input Bypass
AC Input
DC Input
F1
F2
F3
F4
SG Series 10
30 A
15 A
30 A
25 A
SG Series 20
50 A
35 A
50 A
50 A
SG Series 30
70 A
50 A
70 A
70 A
SG Series 40
80 A
70 A
80 A
100 A
