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Installation Guide
LP 33
/ 10 - 20 kVA
Fig. 3.7.2-1 RPA Parallel System
In order to ensure a correct load sharing
between the parallel units, when the
load
is
supplied by
utility
, it is recommended to
keep the cable size and length from the
input distribution board to the output bus-
bar the same for each parallel unit.
Utility Bypass input voltage
must be the
same for all units, thus avoiding phase shift
or phase rotation problems.
To avoid mutual induction effect, the input
cables bust be run in separate conduit from
the output cables.
No transformers, fuses or automatic circuit breakers should be inserted
between the unit’s output and the load common bus-bars.
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.