ST5 Wiring question

[Irish Artist]

Quisp,

This looks like the same ST head set up I have, your on the right track. Yes the two smaller wires were for an indicator light in the old dog house, cap them individually and tuck 'em out of the way. Just be sure they won't hang down and rub on any of the moving parts, remember, there will be some vibration and shaking so you might have to secure them.

Sounds like you have the right wires U5 and U6 are your commons and U1 and U2 will be positives for your two legs.

I verified mine before I wired it all up and put it to bed. I used large clips to hold a set of wires, U1 and U5 so they were close to each other but no contact. Did the same for the other set U2 and U6. Then I fired up the gen and used my multimeter to test the sets for voltage, it was spot on.

Finally, YES!!!! Ground your ST Head, if a grounding screw is not provided, you can ground it to any of the mounting bolts or the cover screws. This should run  to your main grounding block which should also have a ground coming from your grounding rod.

I used a 10/3 fine braided wire to go from my gen head to my first junction box, the same stuff used to run 220 power to an oven. it'll take the vibrations much better than the standard solid romex wiring. I ran my ground with a separate piece of 10 gauge.

Murph'

[Quisp]

Hey Murph!  Sounds good. I just test fired the beast and it all checks out. I had to play with the governor to get 60 HZ. It was only making 55 Hz at first. I have 127 vac on each leg. I still have to sink that grounding rod but for now, everything is grounded to a mounting bolt on the ST5. Since the ST5 and 6/1 sit on the same steel rails, the 6/1 is grounded too.  Is that okay?

Thanks,
Quisp

[Doug]

Some discussion on grounding and bonding needs to happen here and the code requirements for your areas and aplications....

[Doug]

You never want to have a better ground than the Utilities pole transformer trust me.....

The neutral is grounded at the trasnformer ( technicly it is ground only if you want to look at it that way untill you divided it into a common or netraul and your local ground from the service  ).

Anyhow I think if your close enough to your service you should only bond your frame and float the neutral.

If this was in a building a ways away from your home on some conditions I may want to set a second grounding system and isolation for the unit but this is one of my hang ups and local codes get fuzzy aropund this sort of thing ( very fuzzy in my case. ok I am techniclly wrong here running 2 systems and full line isolation for my trasnfer switch). You may or may not have to bond your neutral in your outbuilding utility panle depending on local codes.

You realy need to discuss this sort of thing with an inspector.

Have I confused you?
I can keep typing if not....

[Irish Artist]

Doug is correct, you need to check with your local codes, they can vary. I'm just going to say to be sure to have  ground tied into the gen head frame.

Quisp, ground to your entire gen set frame is fine.

Doug, please do share, I'd like to hear about the ground better than the utilities pole transformer, or was the utilities ground faulty?

[Doug]

Very rare but there are times when the Utility ground is not as good a residential ground. And you can get currents running fronm the utility transformer to YOUR ground. I have seen this actualy heat pipes in a rural home.

A simple clip on amp meter can check there are no issues and if you have a transfer panle installed I would ask the istaller to check for wierd ground currents in your home.

I will be out of town a few days....

[Doug]

When ever I see someone has not connected a ground I question it. Is it because they forgot or are they trying to hide a problem?

I have seen some strange things over the years breakers that would not trip because the ground system was so bad....
Things that would not trip because the ground faults were a perfectly ballanced storm that caused only bubles in the water around the ground system and NGR monitor to trip with no apparent cause.
I even once saw a place where I had to cut the armour and use insualted bushings on tech cables to keep the ground currents from burning things up for no apperent reason ( and I never did find the reason although I suspected induction )

[Irish Artist]

Hey Doug,

Thanks for the response on the utility pole ground question, that was sort of what I was suspecting.

Mind you I'm not a pro at the electrical biz, but I have a firm grasp on the basic principles. Interesting to hear of the various ways that the grounding element in a system can get out of hand. It's one of the most obvious parts of the system, yet so many seem to overlook it's importance. I've heard of folks burning out numerous appliances due to a floating ground and yet they don't have a clue.

hwew, what did you find on your amprobe? all good?