GE FGC TLE Series Manual page 398

NOTE !
This UPS is only designed to operate in a wye-configured electrical system with a
solidly grounded neutral.
The UPS cannot be operated from a mid-point or end-point grounded delta
supply source.
If the UPS is equipped with an input bypass transformer, the secondary of the
transformer must be wye-configured with neutral solidly grounded.
If the Load requires a Neutral, a Bypass Source Neutral MUST BE PROVIDED.
If no Neutral Connection is available with the Bypass Input (3-wires input + ground) and the Load
does not require a Neutral, solidly connect the Output Neutral of the UPS to ground with a ground
bonding jumper.
For single module applications install the ground bonding jumper directly at the UPS output.
Cable size for this connection shall be per National Electric Code and applicable local regulations,
but not less than copper AWG 4/0 or aluminum 350 kcmil.
ATTENTION !
With this configuration, Load can only be connected phase-phase.
Absolutely no Load Connection permitted to the output Neutral.
DO NOT install both a source Neutral and a bonding jumper!
In a Parallel System configuration, the output
distribution cabinet must contain a Neutral Bus
as per the following Figure 4.9.3-2.
If no Neutral Connection is available with the
Bypass Input (3-wires input + ground) and the
Load does not require a Neutral, solidly connect
the Output Neutral of the UPS to ground in the
Output Distribution Cabinet.
Wire Neutral Conductors from the UPS to the
output distribution cabinet (common point of
connection) and solidly connect to ground with a
ground bonding jumper.
Cable size for the ground bonding jumper shall be per National Electric Code and applicable local
regulations, but not less than copper AWG 4/0 or aluminum 350 kcmil.
Please consider the following when applying Ground Fault Circuit Interrupters (GFCIs) in 3-wires
distribution:
• During transfers to and from bypass, circulating current may flow between the the two AC
sources (UPS inverter and bypass utility). In 3-wires distribution the current flows through the
ground path. In order to prevent tripping in such circumstances, proper adjustment of the GFCI
is required. Particularly, the time delay should be set to at least 300ms.
• With the Neutral to ground bonding jumper installed, the UPS ground current has been verified
to be less than or equal to 5% of the maximum rated input current of the unit in compliance
with international safety regulations. This shall be accounted for in GFCIs settings
NOTE !
Failure to properly adjust the GFCI settings could compromise the power delivery
to the critical load.
Modifications reserved
GE_UPS_ISG_TLE_SUL_M62_1M0_2US_V010.docx
Critical Power
Fig. 4.9.3-2 RPA Parallel System
Installation Guide TLE Series 625 - 750 - 1000 UL S2
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