Critical Power
Modifications reserved
Page 45/69
GE_UPS_ISG_TLE_SUL_M62_1M0_2US_V010.docx
Installation Guide
TLE Series 625 - 750 - 1000 UL S2
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 3/0 or aluminum 250 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 4.9.1-2
.
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.
Fig. 4.9.1-2 RPA Parallel System
Cable size for the ground bonding jumper shall be per
National Electric Code
and applicable local
regulations, but not less than copper AWG 3/0 or aluminum 250 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 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.
