# isolated neutral



## ICE (Sep 14, 2013)

There is a meter pedestal with a main disconnect about 200' away from a cell tower.This is a sub-panel at the cell tower.

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This is an automatic transfer switch.  There is also a manual transfer switch.
	

		
			
		

		
	

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Here's the deal.  There are neutral/ground bus and lugs aplenty.  So I asked that the equipment ground be removed at the main and checked that the neutral is isolated at the sub-panel.  It is not isolated.  As near as I can figure, the surge protectors in the ATS are where the neutral and ground are tied.The ATS is made by Kohler and is UL listed.  My problem is that I don't know enough to decide if this is a problem or not.I wrote a correction regarding the non-isolated neutral and will find out more from our electrical engineer on Monday.  I doubt that this has not been addressed by Kohler in the past and the contractor is heading their way.
	

		
			
		

		
	

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## Span (Sep 16, 2013)

Don't forget to ask electrician to use common trip three pole breaker for common neutral circuit.


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## raider1 (Sep 17, 2013)

Span said:
			
		

> Don't forget to ask electrician to use common trip three pole breaker for common neutral circuit.


Doesn't have to be common trip just equipped with an identified handle tie.

Chris


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## raider1 (Sep 17, 2013)

ICE is the ATS listed for use as service equipment?

Chris


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## ICE (Sep 18, 2013)

Chris,

I didn't find that on the label and Kohler is no internet help because the model # isn't recognized.  (KCS-DFNC-0200S)

The continuity between ground and neutral happened because a temporary receptacle outlet was bonded to an equipment enclosure. It's power came from an adjacent enclosure for another cell companies equipment.  The service supplies both company's subpanels.  The neutral for the new subpanel was disconnected at the main and a test showed an isolated neutral.

So the ATS must not be listed for use as service equipment.

285.23 (B) At the Service.

When installed at services, the grounding conductor of a Type 1 SPD shall be connected to one of the following:

*(1) Grounded service conductor*

(2) Grounding electrode conductor

(3) Grounding electrode for the service

(4) Equipment grounding terminal in the service equipment

I learned a few things this time around.


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