3 battery over current protection and wire sizing, Battery over current protection and wire sizing – GE Industrial Solutions SG Series 225 & 300 Installation Guide User Manual
Page 19
3.7.3 Battery over current protection and wire sizing
NOTE !
• 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.
• The 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 maximum available fault current from the battery supply is: 20kA.
• The minimum breaker voltage rating is 540V.
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)
AC Input Rectifier
AC Input
AC Input
Bypass
DC Input
F1
F3
UPS rating
Nom. Max.
F2
Nom. Max.
F4
SG Series 225
338 A
380 A
271 A
338 A
380 A
444 A
SG Series 300
451 A
490 A
361 A
451 A
490 A
592 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
AC Input Rectifier
AC Input Bypass
AC Input
DC Input
UPS rating
F1
F2
F3
F4
SG Series 225
450 A
350 A
450 A
600 A
SG Series 300
600 A
500 A
600 A
700 A
WIRING
Wire sizing according to
NEC Section 210-20 (a) Table 310-16
Use 75°C (167°F) copper wire
Wiring requirements:
AC INPUT RECTIFIER:
3-Phase, 3 wire plus Ground
AC INPUT BYPASS:
3-Phase, 4 wire plus Ground
AC OUTPUT:
3-Phase, 4 wire plus Ground
DC INPUT:
2 wire (positive and negative) plus Ground
Maximum cable diameter that terminals can accept
Refer to torque specifications table for torque requirements
UPS rating
Rectifier Input
Bypass Input
DC Input
AC Output
GND
SG Series 225
2 x 500 kcmil
2 x 500 kcmil
2 x 750 kcmil
2 x 500 kcmil
350 kcmil
SG Series 300
2 x 750 kcmil
2 x 500 kcmil
2 x 750 kcmil
2 x 500 kcmil
350 kcmil
Modifications reserved
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Installation Guide SG Series 225 & 300 UL S2