Juneau
I have an Ultrasource #4582 15kW - for use as emergency b/u power for my home. I found the diagnostics pdf, many thanks. I have a few questions:

1) Can you tell me if this unit has a bonded neutral? Could not find in the Owners Manual.
2) Voltmeter shows the following w/ Idle Control in the OFF position, testing hot to neutral receptacles:

50 amp 4-plug: 117-118v on one leg, 117-118v on other leg
30 amp 4-plug: same as above
12v DC 2-plug: 21.5-22v, 12v at slow idle
Anything wrong w/ this data?

3) Is it possible to safely connect the genset to my garage panel ( 60 amp DPST breaker), which is fed from a subpanel in the house, and installing an interlock switch on the main panel? The garage panel has the earth ground bonded to the neutral bar.
4) If not, and I have to connect directly to the main panel via a cordset and a CB panel interlock, then do I ground the generator outside at the same rod that the panel is bonded to, or is the generator ground already accomplished via the 4th wire on the cordset? If yes, then do both ground and neutral wires from the cordset get connected to the bonded neutral in the main panel? Should the generator have a floating neutral in this setup? If so, how do I determine this, and how do I complete the change from "bonded neutral genset" to "floating neutral genset"?
5) Is there a way to get more than the 50 amps from the generator to the home without running a bunch of extension cords? It is rated for 62.5 amps continuous @ 240v.

Thanks in Advance guys!
Quote
Skip Douglas SkipD
Your garage sub-panel must have [U]totally separate[/U] neutral and equipment grounding connections. ONLY the panel that has the primary disconnect for the utility power feed may have the neutral and equipment grounding wiring bonded together.

The best way to connect your generator into the house wiring, by far, is to use a properly designed manual transfer switch. The critical circuits would be re-wired into breakers in the transfer switch panel. The utility power for the transfer switch would come from a two-pole breaker in your main breaker panel. Thus, the breakers for the critical circuits in the transfer switch would be powered either by utility power or generator power.

The only way you can safely get more than 50 amps from the generator would be via multiple cords and some very careful power calculations so that you don't overload one side or the other of the generator.
Skip Douglas
Quote
Juneau
SkipD;8721 wrote:
Your garage sub-panel must have [U]totally separate[/U] neutral and equipment grounding connections. ONLY the panel that has the primary disconnect for the utility power feed may have the neutral and equipment grounding wiring bonded together.


Thanks SkipD for your reply, but what about the following exception?

250.32 (B)(2)

Allows a detached building to be fed with three wires and have the panel neutral and grounding bus to be bonded. There must be no continuous metallic paths between the buildings.

Looking for clarification on this. If above is correct then, when they say Neutral and grounding bus bonded, Do they mean to say, "Bonded in the panel on the same bus, AND that ground is defined as a wire to an electrode?" as in, a second electrode, in addition to the one at the main svc panel, that would be outside of the garage?
Quote
Skip Douglas SkipD
Juneau;8724 wrote:
Thanks SkipD for your reply, but what about the following exception?

250.32 (B)(2)

Allows a detached building to be fed with three wires and have the panel neutral and grounding bus to be bonded. There must be no continuous metallic paths between the buildings.

Looking for clarification on this. If above is correct then, when they say Neutral and grounding bus bonded, Do they mean to say, "Bonded in the panel on the same bus, AND that ground is defined as a wire to an electrode?" as in, a second electrode, in addition to the one at the main svc panel, that would be outside of the garage?
What version of the NEC are you looking at? I have the NEC 2008 Handbook and I don't get the meaning that you are suggesting.

We've got a few real experts on the NEC in the forum and I hope they pop in here to help out. I'm not a licensed electrician, though I've worked with industrial electrical systems for many years.
Skip Douglas
Quote
Juneau
I'm sorry, the exception was removed in NEC 2008.
Quote