Is output of a UPS considered a separately derived system?

[Machiavelli999]

I am wondering if a grounding electrode conductor is needed to be tied into the output ground bus bar of a UPS system. This Mike Holt page (http://www.mikeholt.com/technical.p...tems&type=u&title=Separately Derived Systems [Transformers,%20Generators,%20etc.]%20%284-10-2K%29)
says the following:

"A separately derived system derives its power from a transformer, generator, converter winding, batteries (UPS), or from a solar photovoltaic system."

But it also states,

"Other Systems - Generator, converter winding, UPS systems, or power from solar photovoltaic system are only considered to be a separately derived system, when the grounded (neutral) conductor in the transfer switch is switched"

The output of my UPS is not fed into a transfer switch, so I am wondering whether or not I need a grounding electrode conductor.

 

[ron]

It depends. You need to tell us more about the type of UPS topology, whether there is 4 wire input / output, is there a static and maintenace bypass circuit and is it 4 wire?

 

[ceb58]

I am wondering if a grounding electrode conductor is needed to be tied into the output ground bus bar of a UPS system. This Mike Holt page (http://www.mikeholt.com/technical.php?id=grounding/unformatted/Separatesystems&type=u&title=Separately Derived Systems [Transformers, Generators, etc.] (4-10-2K))
says the following:

"A separately derived system derives its power from a transformer, generator, converter winding, batteries (UPS), or from a solar photovoltaic system."

But it also states,

"Other Systems - Generator, converter winding, UPS systems, or power from solar photovoltaic system are only considered to be a separately derived system, when the grounded (neutral) conductor in the transfer switch is switched"

The output of my UPS is not fed into a transfer switch, so I am wondering whether or not I need a grounding electrode conductor.

You have answered your own question. You are not switching the grounded conductor so it is a non- SDS. We have over 200 1phase 4 wire UPS and none have their own GEC.