16 Configuring YourNeutral and Ground Connections
7.2 Grounding Configura tion, 480 or 600 VAC Input and Output, Delta Source
Figure 4 Grounding Configuration with Ungrounded De ltaSou rce Input
As previously mentioned,Series 600T UPS systems require a bypass input netrual for sensing
and monitoring. With a wye-connected input source,t he installershould always connect the
building service neutral to the System Control Cabinet (SCC) output neut ral to achieve this.
When the building service is delta-co nnected, however, the installer must take special ste ps to
ensure reliable UPS fu nctioning.
If building service is ungrounded delta (andthereisnointenttooperatewithonecornerofthe
delta grounded, either on purpose or accidentally),the SCC requires the Series 600T Artificial
Neutral Kit for proper operation.This kit uses a resistor network to create a reference point for
the bypass input. In this case, th e SCC output neutral must be bonded to the SCC groun d.
If the building service is corner- grounded delta or an Impedance-ground ed wye, the SCCrequires
the Isolated Neutral Kit. This kit uses control isolation transformers to create a reference point.
For this application, the SCC output n eutral mustnot be bonded to the SCC groun d.
NOTE
The Artificial Neutral Kit introduces a maximumc urrentof 0.3 amps to
ground. Take care to ensure that t his does not interfere with the operation
of any upstreamground-fault detectiondevices.