Do small generators require a ground rod?

[fdew]

 

I am an electrical contractor. If you use the outlets on the generator, you do not need a ground rod. The ground rod requirement is for larger units equipped with lugs to hard wire a distro, transfer switch etc. to. I always use ground fault pigtails at the generator. They protect everything downstream. If you don't you are asking for trouble. Most people do not understand what a ground fault is. On an outlet, the two vertical slots are a hot and a neutral, in laymens terms, a supply and a return. A GFI monitors each of those wires, for the device to operate, they need to be balanced. What comes out of the hot wire needs to return on the neutral or it's going someplace astray, ie: your old Fender amp is frying you through the guitar strings cause you are barefoot and standing in a puddle of beer. There is also a monitor on the ground prong that will trip at 4-5 milliamps if I remember correctly. I'm sure there are citys and towns here and there that will want one but 99% of all portable and temporary installations do need require one if you use the outlets provided on the generator.

 

 

 

+1 Very good post. Bottom line, use a GFCI It will protect you with or without a ground rod.

 

Also, they are cheep, and easy to get and install. no reason not to.

 

Frank

[mshifflett]

Good point. I do carry GFCI's for outdoor shows and I think they provide better protection in a situation like this than a ground rod would

 

Would it be okay to use your normal distro box and then put GFI quad boxes in line before the power goes to anything downstream? Or would it be better to build a second distro box with GFI breakers in it?

[STRAT TOOL]

 

Would it be okay to use your normal distro box and then put GFI quad boxes in line before the power goes to anything downstream? Or would it be better to build a second distro box with GFI breakers in it?

 

 

When we do camlok stuff, our distro has GFI's in it. We feed the distro at either 100 or 200 amps. You'd spend a fortune getting a ground fault for that ampacity, so you protect your cordage and whatnot from the distro.

[STRAT TOOL]

 

When talking about the safety of performers, ALLWAYS drive a ground rod. All you have to do is electrocute one performer to get a rep as a dangerous provider.

 

 

 

and what purpose do you think this really serves with a portable generator?

 

ground faults are a requirement and protect people. ground wires provide a fault path for electricity that has gone astray. the only thing ground wires do is ensure that the circuit breaker where the circuit originates from trips. this is why all wiring from the generator need to have equipment gound conductors (the green wire in the cord). The neutral and the green wires are all connected together at the generator frame since it is a seperately derived system. I really see no point in a rod on a portable system with built in outlets and over current protection. If you had NO GROUND wires in any extention cords, and you had a hot to ground fault and yet had a ground rod at the generator, it would do {censored} unless you were in a salt marsh and had superior ground conductivity. Maybe help fry some earthworms along the way.. If you had a metal stage, you would be better served to provide a correctly sized bond wire from the generator frame to the stage trailer.

[Coaster]

AFAIK code requires ALL outdoor edison outlets must be GFCI, genny or not.

[RoadRanger]

If you had a metal stage, you would be better served to provide a correctly sized bond wire from the generator frame to the stage trailer.

I'd be inclined to do that unless there is some good reason not to?

[Dogoth]

Oh, and do yous guys call digsafe before you drive a rod?

 

I usualy use some kind of protection but I don't call anyone

 

Sorry! I just had to.

[Keyrick]

The use of a ground rod provides a reference. If you are out in the middle of nowhere with no other power source nearby, it doesn't do much, unless you are in the middle of experiencing an electrical storm. In that case, your equipment is now at the same potential as the other earth bound materials around you. If there are no atmospheric electrical anomolies occuring at your location, a ground rod isn't necessary.

 

If you are using a genset to augment another power source in the vicinity, and there is a chance that the two grounds will meet, then a ground rod will provide a reference to your genset. Without a ground rod in this case, there is no reference between the power sources and there is no way to predict what the outcome would be should the two sources interact.

[kevinnem]

I though tha grounding rods where for lighting issues. How do they pretain to electical useage in this context.

 

Also, someoen mentiuoned going form L5-30 to a "quad box". What do you have in this quad box? more L5-30's???? I would think you would need a break for 15, or 20 amp plugs.

[RoadRanger]

Also, someoen mentiuoned going form L5-30 to a "quad box". What do you have in this quad box? more L5-30's???? I would think you would need a break for 15, or 20 amp plugs.

Yah, not "code" but I've seen one. I've even seen a 3 pin range plug on a quad .

[Craig Vecchione]

 

Also, someoen mentiuoned going form L5-30 to a "quad box". What do you have in this quad box? more L5-30's???? I would think you would need a break for 15, or 20 amp plugs.

 

 

Correct. That was Axisplayer stating he uses a 30amp cord into the L5-30 circuit on a genny.

 

While the "tap rules" allow you to feed multiple 15-amp Edison receptacles via a 20-amp branch circuit, a 30-amp branch requires separate overcurrent protection for either 15- or 20-amp recepacles. So the quad box can't be used. He'd need a breaker panel in place of the quad box and either 15 or 20 amp breakers for the receptacles. What he has is rather dangerous, as an overload or partial/intermittent short could easily heat the cordsets plugged into the quad to the point of a fire.

[Craig Vecchione]

Yah, not "code" but I've seen one. I've even seen a 3 pin range plug on a quad .

 

Some people seem to think that if the parts can be connected together, it must be okay. Some of them are no longer with us.

[Axisplayer]

Yea, I knew the receptacle was rated for 20 amps. The issue was that the receptacle on the Honda puts out 20 amps and the twistlock is a L5-30, but the power output is actually only 23 amps, not 30 amps. I opted to use it knowing I was off a few amps, but it is the configuration that I bought for this unit online. I agree it is suspect and will probably modify it if I continue to use it.

 

You will find it being sold from a generator shop online at this site:

 

http://www.mayberrys.com/honda/generator/html/accessories.htm

 

It is near the bottom listed as Convenience Cable. I did not home-build it. I bought it that way and expected it to be acceptable when delivered.

[BillESC]

It would seem to me, plugging a plug strip into the gennys outlet IS using the genny's outlets. No rod required. That would go for the L5-30 as well.

 

You are only using the units outlets.

 

YMMV.

[Axisplayer]

Bill. that is true. the concern Craig has is that the outlet is an L5-30 twistlock carrying 23 amps but feeding a quad box with receptacles rated for 20 amps, where the quad box had no 20 amp breaker to guarantee that a fire won't occur. I am sure that he is technically correct as he is an electrician. I bought the cord online from a generator shop, expecting that it meets whatever requirements are in place or it couldn't be legal to sell. Probably not legal after getting it, but it is a commercial product, not something I designed and built.

 

EDIT: Just checked the box. It's from Gen-Tran and does have two internal 20-amp circuit breakers.

[RoadRanger]

 

It would seem to me, plugging a plug strip into the gennys outlet IS using the genny's outlets. No rod required. That would go for the L5-30 as well. You are only using the units outlets. YMMV.

What if this was my "power strip":

http://www.northerntool.com/shop/tools/product_200326702_200326702

I don't see any real legal difference between that and a power strip that has a 15 amp breaker and switch? They both plug into an outlet on the generator and provide multiple 15 amp outlets.

[Keyrick]

 

What if this was my "power strip": http://www.northerntool.com/shop/tools/product_200326702_200326702 I don't see any real legal difference between that and a power strip that has a 15 amp breaker and switch? They both plug into an outlet on the generator and provide multiple 15 amp outlets.

 

 

Well, if were talking about a Honda 3000, it is only a 120v genset, and that is a 125/250v distro.

 

Just sayin'...

[Redbassman86]

 

While the "tap rules" allow you to feed multiple 15-amp Edison receptacles via a 20-amp branch circuit, a 30-amp branch requires separate overcurrent protection for either 15- or 20-amp recepacles. So the quad box can't be used. He'd need a breaker panel in place of the quad box and either 15 or 20 amp breakers for the receptacles. What he has is rather dangerous, as an overload or partial/intermittent short could easily heat the cordsets plugged into the quad to the point of a fire.

 

 

That's not actually the "tap rules". The 10, 25, and 100 tap rules require you to terminate into some form of overcurrent protection. What allows you to connect 15 amp plus onto a 20 amp circuit is that you cannot plug a 20 device into a 15 amp receptacle, so 15 amp devices will carry the 15 amps you could call for from a single device. Most 15 amp devices are rated at 20 amp "feed through", meaning you can use both sets of screws without a pigtail. If it's not rated as a feedthrough, you must wire a pigtail to the plug. I'll look up the code article pertaining to what you mentioned when I can find that damned code book.....

[RoadRanger]

Actually this looks like the proper quad box to run off a L14-20 (which is probably what my generator has) :

http://www.homedepot.com/h_d1/N-5yc1vZ1xga/R-202019458/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

 

They make a whole bunch of different ones:

http://www.homedepot.com/webapp/wcs/stores/servlet/Search?keyword=convenience+cord&langId=-1&storeId=10051&catalogId=10053

[Redbassman86]

210.21 b

[Craig Vecchione]

That's not actually the "tap rules". The 10, 25, and 100 tap rules require you to terminate into some form of overcurrent protection. What allows you to connect 15 amp plus onto a 20 amp circuit is that you cannot plug a 20 device into a 15 amp receptacle, so 15 amp devices will carry the 15 amps you could call for from a single device. Most 15 amp devices are rated at 20 amp "feed through", meaning you can use both sets of screws without a pigtail. If it's not rated as a feedthrough, you must wire a pigtail to the plug. I'll look up the code article pertaining to what you mentioned when I can find that damned code book.....

 

Funny, cause around here what I described is called "tap rules" by tradesmen. This is the kind of stuff that drives me nuts. Local "knowledge".

 

What's never made sense about what you describe is that a partial short on a 15-amp device plugged into a 20-amp branch with 15-amp receps can still start a fire before the 20a OCP opens the circuit. Since NEC is all about fire protection, I'm surprised this has been allowed. Consider that something like a radio has 18 gauge cordset, and is on a 20amp breaker circuit. That's small wire that can easily heat.

[Redbassman86]

Funny, cause around here what I described is called "tap rules" by tradesmen. This is the kind of stuff that drives me nuts. Local "knowledge". What's never made sense about what you describe is that a partial short on a 15-amp device plugged into a 20-amp branch with 15-amp receps can still start a fire before the 20a OCP opens the circuit. Since NEC is all about fire protection, I'm surprised this has been allowed. Consider that something like a radio has 18 gauge cordset, and is on a 20amp breaker circuit. That's small wire that can easily heat.

 

Haha, yea, tap rules are completely different. Mostly now only referenced generally for transformer disconnects. As far as the fire is concerned, the 20 amp part only matters for over current, ie too many radios plugged in. When it comes to a short circuit, another rating takes over, the AIC rating, typically 10k on a household branch circuit, 22k for the main. The current that makes that breaker trip is in excess of 10k amps fault current, so the wire size is sorta irrelevant. The wiring sizing is meant to prevent heating on regular loads, no so much faults. A transformer will deliver up to 20x the nameplate amperage in a fault.