operating mep-003 in a snow storm

[Isaac-1]

What kind of transfer switch do you have?

 

[Bill W]

What kind of transfer switch do you have?

Previous owners put in a sub panel coming off the 400amp breaker box I have. The sub panel runs limited outlets/lights in the house including well pump and hot water heater, it was originally setup for 30amp hubbel I have since put in 50amp hubbel ( and heavier guage supply)

 

[Isaac-1]

Remember I am not a professional, but based on my understanding of the NEC it looks like you have a switched neutral at the transfer switch, so you would be under the rules for a separately derived source. So it looks like grounding and bonding needs to be done at the generator in your case.


Have ground rod at the generator and connect neutral to frame and ground rod.

Keep ground separate going into the transfer switch

There should only be one point where ground and neutral are tied together in the circuit path

Hopefully someone else will be along soon, to confirm what I said.

Ike

 

[Bill W]

ok from what your describing then I leave my genset the way it is which ( as I understand it ) is to keep it with the ground/neutral tied together ( bonded ) and not seperate them. Now the ground is unbroken ( no switch ) allthe way into the panel(s) so why would I need to have another ground rod at the genset

 

[PeterD]

I'd totally rewire that (manual) transfer switch. The wire sizes are way too small (much looks like 12 AWG!) and as well, like Ike mentions switched neutral is not good. I'm sure the wire is too small a gauge to properly fit the terminals on that switch (or the breaker panel) as well. All connectors such as this are rated for a minimum and maximum AWG wire size--too small a wire and the connector won't properly clamp it and you end with a potential high resistance connection.

Add up the loads in the box that is feed by the transfer switch, and size the wire appropriately.

 

[Bill W]

OK
One problem at a time
My hubbel line supply is 8ga
Panel wires are 10ga ( yes they should be heavier but have been in use for the last 21 years and look fine ) I've read that a switched neutral is nice to have so as to not have any possible feedback to the pole and zap a linesman....yes/no???.
So my original question still stands do I seperate the ground/neutral bond at the genset

 

[Speddmon]

There is absolutely nothing wrong with having the neutral switched. As far as I'm concerned, I would prefer it that way. By switching the neutral, you have to do nothing to your generator other than drive a ground rod and run it. Then if you want to move the genny and run a remote shop or some other equipment, just disconnect the ground rod and go. When you come back to hook back up to the house, just re-attach the ground rod and you are set.

Just do as Ike mentioned, and leave the genny neutral/ground bonded and drive a ground rod and run the crap out of it.

 

[PeterD]

Here is a good PDF on the subject of switching neutral, and some of the reasons to switch or not to switch it. http://www.kraftpower.com/pdfs/KPC_Info_05_switching_neutral.pdf

I'm sure I could also look up similar references in the current NEC code book (but one would need to know what level of the code is applicable at the installation, for example).

Like many things, there is no absolute do or don't on switching neutral conductors, however, personally, I would normally not switch it in a residential installation where single phase power is being used.

The fact that a transfer switch is being used is great, I see so many people just back feeding and creating some rather hazardous configurations!

 

[Isaac-1]

On the whole switched neutral question, there area couple of schools of thought, each one has points. One of the big ones has to do with switching a live load and having flexure in the switch contacts particularly on a non spring loaded standard (not quick) knife switch that might allow the neutral to break before the lines leaving the voltage to go crazy momentarily. Since yours appears to be a good quality heavy duty quick acting switch this is less of a concern.

Ike

 

[Bill W]

Thanks for the help guys
but I'm still a little thick on why I need to have a ground rod in addition to the genset being grounded to the house service through the ground wire in the 6/4cord.

Ike
It is a excellent switch box but regardless I would never throw the switch while it was live, I've pulled to many shore cords in my life and know to shut the breaker first

 

[Speddmon]

Thanks for the help guys
but I'm still a little thick on why I need to have a ground rod in addition to the genset being grounded to the house service through the ground wire in the 6/4cord.

Don't know why? What would happen if your ground wire going to the house were to break and something were shorted on the generator....you go out to check the set to make sure everything is running good, lean against a metal part in the pouring rain and ZAP...no more Bill W.

It's there as a safety precaution. Can you probably get by without it for many years just fine? Yeah, probably...Do you want to be that one in a million chance that there could or would be a problem and find out the hard way? Probably NOT!

 

[Isaac-1]

In your installation I think you are planning to connect the generator to the house with removable SO cord, think about Speddmon's above example, but when you are just test running the generator without the house load connected. It just makes safety sense to have the ground rod as close as practical to the generator. One of the points I question about the NEC on this topic is the requirement to use solid ground wires, it seems to me stranded or a braided strap would be safer for vibration stress.

Ike

p.s. a ground rod only cost about $10, plus some time with a hammer

 

[Bill W]

Safty precaution....Go Figure

Thanks guys

 

[O.D. Fever]

Good news, The Epic snow storm made me try to start my mep002 that is by my power pole. It has been 2 months and has hit 10 below 3 times and 20 below once. I was going to bring the slave cables home just in case.. IT started up on its own power with the batteres from the GOOBERMENT.. Go figure, Then I new it was going to be a small storm..

 

[ken]

As far as running it in the storm goes. Mine ran the house during hurricane ike. It's a wonder it didn't drown. And then the community water well for two weeks after my house power came back on. It was uncovered in the back of my M105, and never skipped a beat. Just get plenty of diesel. I averaged 1.1 gallons per hour.