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#165285 - 06/24/07 11:05 PM revist iso transformer
watersparkfalls Offline

Registered: 03/08/05
Posts: 210
Loc: Washington...Not DC
my iso transformer passed inspection with everything bonded(frame,equipment bonding from panel,x2,x3,bonding bushing,neut to sub and equipmet bonding to sub)all done at the transformer.
but according to acme (depending on tech that answers phone) i should drive ground rod and have new ground reference for true isolation.
so here is my question this time around.
what if i drive a new ground rod(as tech specified) and from this new ground rod, i run a wire to the other ground rod already driven(which is bonded with cold water via main panel)now i seperate egc's at transformer and intentally ground x2,x3 to new ground rod for isolated neut at sub panel? the house would still have a single grounded reference point and it should be electrically safe and nec complient wouldn't it? i am doing everything to install so i do have an isolated system...thus any noise that could/should appear later on will not be because of installation. KEEPING in mind Safety is my first priority!
what is your guys opinion of this idea?

2014 / 2011 NEC & Related Books and Study Guides
#165300 - 06/25/07 08:13 AM Re: revist iso transformer [Re: watersparkfalls]
resqcapt19 Offline

Registered: 11/10/00
Posts: 2209
Loc: IL
First the transformer secondary requires a connection to a grounding electrode. Second both the primary and secondary EGCs must be connected to the transformer frame and case. In fact a truely isolated system is not possible if you are in compliance with the NEC with some very rare exceptions such as hospital operating rooms.


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