9 rpa parallel system connection, 1 power wiring of parallel units, Rpa parallel system connection – GE Industrial Solutions SG Series 10 – 20 – 30 – 40 kVA Installation Guide User Manual
Page 36: Power wiring of parallel units
3.9 RPA PARALLEL SYSTEM CONNECTION
WARNING !
This operation must be performed by trained personnel before the initial start-up.
ENSURE THAT THE UPS INSTALLATION IS COMPLETELY POWERED DOWN.
3.9.1 Power wiring of parallel units
To guarantee good Load sharing between the units of a parallel system, we recommend that the cable
length from the input distribution board (5) to the output distribution board (10) is equal for each unit
(a+b = c+d = e+f = g+h = i+l = m+n = o+p = q+r).
Tolerance: +/-10%.
The AC input power of the Bypass must be the same for all units of the parallel system - no phase shift
allowed between units.
NOTE !
It is strongly recommended that no transformers, automatic circuit breakers or fuses
should be inserted between the unit’s output and the Load common bus bars.
However, it is recommended that a disconnection or isolation switch is installed in
order to totally isolate a unit if needed.
1
= Rectifier
2
= Inverter
3
= Automatic
Bypass
4
= Manual
Bypass
5
= Input
Utility
Distribution
6
= Unit Output Load
External Battery fuse or
MCB
7
=
8
= External
Battery
Common bus-bar and
Output Load Distribution
9
=
= UPS Number 1
2
= UPS Number 2
3
= UPS Number 3
4
= UPS Number 4
5
= UPS Number 5
6
= UPS Number 6
7
= UPS Number 7
Fig. 3.9.1-1 Power wiring of RPA Parallel System
8
= UPS Number 8
Modifications reserved
Page 36/45
OPM_SGS_ISG_10K_40K_0US_V040.doc
Installation Guide SG Series 10 –20 – 30 - 40 kVA