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Site Wiring Fault" message on Symmetra LX UPS Systems


A Symmetra LX UPS system reports a "Site Wiring Fault" message.

Product Line

Symmetra LX


All serial ranges


The Symmetra LX UPS split-phase UPS system is designed to operate off nominal input voltages of either 208V or 240V consisting of 4 Wires: 2 phases, a neutral and ground. Given that, there are two possible causes for this message:

1.) If the UPS does not detect a good neutral connection, it will report a Site Wiring Fault if the Intelligence Module master firmware revision is 512 or greater. The SYPM4KP Power Modules, regardless of firmware revision, will rapidly click until the Neutral connection is corrected.  This is documented in knowledge base article FA157501.

2.) The individual input phase voltages should each be 120V. In the event that there is an 8% voltage difference between the 2 phases (i.e. phase (1) reports 120V and phase (2) reports 105V), the UPS will indicate Site Wiring Fault but take no action otherwise.  In the event that there is a 10% voltage difference between the 2 phases, the UPS will respond by operating on battery power with the Site Wiring Fault message.


To prevent this alarm from occurring, the input AC service/wiring will need to be corrected.

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