Grounding and 3-Pole Transfer Switch


Senior Member
If I have a generator that is set up as a separately-derived system (i.e. neutral to ground bond at the generator), is using a 3-pole transfer switch instead of a 4-pole transfer switch a violation of code as it pertains to having more than one neutral-ground bond in the system?

I'm looking at a facility where they left an existing 3-pole transfer switch in-place when upgrading their emergency generator system to a large, separately-derived system. Not sure if I'm spotting a code-violation or just poor design?