RV Breaker Panel vs Home Breaker Panel

[family wagon]

I did an idiot thing once. Well, that has happened more than once, but there's one occasion in particular which I'll share now. I wanted to test a portable generator powering the house. I've done this before without incident, but having traded out that former generator for a smaller unit, wanted to test again. We had moved to a different house, too. Anyway I wired the 240 volt hookup with a 3-wire cord because I was backfeeding through the electric range socket which had 3 conductors. The generator of course had the 4-wire L15-30 connector... unfortunately I connected the house ground, which I knew would be bonded to the house neutral back at the main panel, to ground on the generator's L15-30 rather than neutral. This generator doesn't have a built-in bond. It only took a few seconds to figure out that because the neutral was disconnected, some parts of the house were experiencing well over 120 volts while other parts were well under. Fortunately the "double check the neutral and ground!" lesson tuition only cost me one fluorescent ballast, a handful of CFL lamps, two surge suppressors, a wall-wart transformer, and the ice maker in the freezer. It could have been much worse.

[skoolie_n00bie]

This is what i'll be using.
Very high-tech...I think McCoy left it behind....

[Piersg]

Ok, so just to clarify this in my mind, when I install my PD4560 50 Amp all in one center, I'm going to run a green wire from the grounding block to the frame/chassis of the bus, like in the diagram below (I added the green):



Does this look right?

Thanks!

[Jolly Roger]

Originally Posted by ol trunt

The no shock zone should be mandatory reading for all us bus nuts!!!!!!

If you are using a portable generator like Honda or Yamaha you will need to change their floating grounds so that they ground back to themselves. Many portable generators have a ground lug on the control panel that the mfg suggests you wire to a grounding rod---how likely is that going to be? You can find a listing of generators with floating grounds and how to make their grounds go back to the generator rather than a ground rod. With a floating generator ground, it is possible for the "skin" of the bus to become hot (electrified). Under those conditions, should you happen to step out of your bus onto wet ground while you are still, say, hanging onto the step rail, you get to be the ground----a shocking (and potentially deadly) experience. Jack

I was trying to play catch up and read all the post before I commented but TRUNT and I still have not read the no shock zone.
For government construction we are required to use a grounding rod for any portable generator,welding machine and most BS it buy driving a piece of steel whatever in the dirt to look like something and hook jumper cables from rod to equipment frame.
All generators are vibration isolated but have steel bolts through the isolators to the frame but have a ground to frame but as stated it could be unreliable.
For me a ground rod driven into the ground at least 18" and a good sized ground wire connected to the generator ground lug not the frame lug and clamped to the rod is true protection.
With all of that said and everything we do to these busses? Has anyone ever thought about grounding the bus body and a rod on the roof for lightning protection? Because even though the frame is isolated with tires the body is isolated from the frame to an extent?
Laugh if you want to.
Government/base high rise construction they come up with all kinds of electrical safety issues among other things?
I am usually a water man but my company involved me in electrical solar panels on a 5-story metal roof and I had to add seperate lightning protection because lightning looks for a path to ground and all the power from these panels are grounded. And because I was the installer of 70+ panel solar water system I had to install lighting protection on them as well? (Not the owner of the company just the ramrod installer) sucked either way. Water piping does create a path to ground and We did use copper for the glycol/water system so had to ground the piping on the roof and on the first floor at the equipment? Probably over kill but it has put food for thought in my head as far as grounding in/on my all metal structure bus? And what to ground where? Lightning if grounded to the body could blow everything you have including you,unless it is provided a direct path to ground? Ain't scared of it but I swear growing. Up as a kid in texas my DAD was a lightning rod never hit directly but close enough to cause temp. Blindness and 1 time it was because he came to close my bedroom winder after I ignored mom telling me to. I jumped and said ok I got it dad and as soon as he touched the winder the lightning was close enough it temp.blinded both of us? My first but his third?

[family wagon]

Piersg: yes that looks good.

[ol trunt]

FYI Trunt has read and understands the "No shock zone" So what's the prob?

[Arvik]

Originally Posted by ol trunt

FYI Trunt has read and understands the "No shock zone" So what's the prob?

i can attest to this, he has heard my ideas for fishing worm gathering and concluded it was indeed very dangerous and very mucho in the shock zone.

[Jolly Roger]

Originally Posted by ol trunt

FYI Trunt has read and understands the "No shock zone" So what's the prob?

Sorry TRUNT/sir i just read my last post and I made it sound like you havent read or dont know? i am sorry. that wasnt my intention?? i started out posting in one direction and didnt start completely over when i changed direction? I meant to say that you had hit on a topic that i had debates in my head about and went on to explain my debates and didnt see that i had thrown you UNDER THE BUS? SORRY. i will make it to the NO SHOCK ZONE this weekend to answer the questions in my head about grounding.
No problems here sir.
Thanks for your time.

[Arvik]

lol no inside joke or anything, i was tellin trunt the other day on different thread that i had wired a male to male extension cord to test my ac circuits, BAD idea. so i said id use it for a worm gathering aid and stick it in ground for a bit then go get the worms that had run for the hills!!

[TAOLIK]

Question: how many switches do you guys use on your breakers and how many watts is your electrical system? I know it's need based but I am curious. I have a RV breaker with a few switches that I am thinking about hooking up, but was wondering about this the other day.

My system will be 1000watts with a small generator so I don't know if I need more than a few switches. 1 for the occasional heavy load like the wife's hair dryer, 1 for the kitchen, 1 for the livingroom and bedroom?

[The-Breeze]

NO SHOCK ZONE for those interested:

http://noshockzone.org/15/

or......

http://www.skoolie.net/forums/f10/rv...fety-7862.html

[Soaringcook]

Hi all,

What the difference in wiring an rv 120v panel and a home subpanel?

[Hiyu]

I just installed a PD 4100, AC DC with a battery charger, piece of cake and it exceeds all my nees!

[Rwnielsen]

Originally Posted by cadillackid

so I have a question... isnt it a bad scene to be grounding your 110 volt panels to the same frame that alot of your 12 volt stuff is grounded to? shouldnt you be running grounds to each appliance / receptacle.. and then WIRING a ground to the Generator or to the Shore power connection? and leave the Bus frame for the 12 volt stuff?
-Christopher

Short answer, yes. Don't ground your 120 volt to the bus unless the bus is grounded ie: ground rod or grid. Otherwise you may be standing outside, possibly wet and complete the ground circuit. The dreaded hot skin scenario

[Rucker]

Originally Posted by Rwnielsen

Short answer, yes. Don't ground your 120 volt to the bus unless the bus is grounded ie: ground rod or grid. Otherwise you may be standing outside, possibly wet and complete the ground circuit. The dreaded hot skin scenario

This questions keeps coming up, so help me understand this a little better.

From all of my research it's perfectly okay to ground both 12VDC and 120VAC systems to the chassis frame and in fact preferable. For the DC, the ground is the return path to your battery negative terminal-no issues sharing the AC ground because, well, AC circuits are not completed anywhere in the DC circuit. They only complete with the neutral conductor of an AC circuit, or under a fault condition, which is real but rare.

When powered by shore power, the 120 V AC lines with a ground wire connected to the chassis acts as a conductor back to the shore power ground rod under a fault condition. Normally it doesn't have any voltage potential but if it did you really want it to drain off that way, not through your body to literal ground, which is the only path it would have if you don't bond your AC ground to chassis.

Of course, if shore power ground is not grounded then all that potential from a short is just sitting there waiting for you to grab the bus. A real scenario, but much less likely than a short from the hot wire to metal on your bus (or less common but certainly dangerous reverse polarity bootleg ground: Are "Little" Shocks OK? | No~Shock~Zone ); and without that chassis ground to shore power ground you're gonna feel that.

For generator power it is the same principle. I have less experience with them but from what I've read it is smart to ground the generator (yes, I know, nobody does that. And it's also true we don't often see short conditions. So 'I've never grounded my generator and never had a problem' is not a statement to rely on)

Here's the relevant link on grounding from the no-shock zone that's my go-to source for a lot of this info: Generator Ground-Neutral Bonding | No~Shock~Zone

Am I missing something?

[rossvtaylor]

Looks to me like you've got a good handle on it, Rucker. In another thread...or maybe this one earlier?...I did mention parking on a ground plate or using a short stake to provide an "Earthed" ground when parked. But like you said, nobody does that in real life. Regardless, it sounds like your understanding of all this is thoroughly grounded.

[NOWHERE13]

Hello, Article 551 in the NEC covers grounding for us pretty good.

[Rucker]

Originally Posted by rossvtaylor

Looks to me like you've got a good handle on it, Rucker. In another thread...or maybe this one earlier?...I did mention parking on a ground plate or using a short stake to provide an "Earthed" ground when parked. But like you said, nobody does that in real life. Regardless, it sounds like your understanding of all this is thoroughly grounded.

Trying to think of a clever comeback to your play on words, but I fear I might become a lightning rod for jokes!

[Rwnielsen]

Originally Posted by cadillackid

so I have a question... isnt it a bad scene to be grounding your 110 volt panels to the same frame that alot of your 12 volt stuff is grounded to? shouldnt you be running grounds to each appliance / receptacle.. and then WIRING a ground to the Generator or to the Shore power connection? and leave the Bus frame for the 12 volt stuff?
-Christopher

Yes
Single point ground, at the source, either generator, shore power, wind, solar.... The NEC does not allow multiple grounding. I've tried to explain, to deaf ears, too many times to get involved.

[NOWHERE13]

Hello Rwnielsen, check out Article 551.56 A-D.