Grounding Rod For Portable Generators Necessary?

[whistlepig]

For computers, TVs, and the delicate stuff its better to buy an inverter generator. When our power goes out the generator powers the two fridges, freezer, well pump, pellet stove, electric skillets, and some lights. No TVs, computers or delicate stuff. Ours isn't an inverter generator.

 

[zmjc]

I've had enough shocks in my life to be tired of them now, so I pound some scrap copper pipe into the soil to use as a ground rod with my little lug-around generator...

 

[PoorPlowboy]

My guess is it happened because the generator did not supply clean enough power.

You should use a computer back up power supply, (UPS), between the generator, and electronic appliances until you know your generator set up is safe for your equipment. The UPS is designed to filter the power, and make it safe.

Generally inexpensive generators are not good for supplying clean power.

The ground rods are to protect the user, in the even to a short in the generator. If it functions as it should, you won't need it. If the generator ever fails, and shorts out, it could be very dangerous. Without a good ground, you could become the ground, and that's not going to be good.

While a UPS type power supply will do the job, a standalone power line conditioner/filter is a bit more portable for using with portable generators. I have a couple of these that I use for all of my computing or tv watching while on generator power.

Amazon.com: Apc Av C Type 2 Outlet Wall Mount Power Filter, 120V: Electronics

 

[jonyyuma]

While a UPS type power supply will do the job, a standalone power line conditioner/filter is a bit more portable for using with portable generators. I have a couple of these that I use for all of my computing or tv watching while on generator power.

Amazon.com: Apc Av C Type 2 Outlet Wall Mount Power Filter, 120V: Electronics

The APC ups units are exactly what I was refering to, for clean power. It is type I have except it is a 750. Thanks for the reference page.If it is not real critical load,I will use the protector strip, but they come in all types. Mostly by cost as to the protection provided.Jy.

 

[eastexan]

While a UPS type power supply will do the job, a standalone power line conditioner/filter is a bit more portable for using with portable generators. I have a couple of these that I use for all of my computing or tv watching while on generator power.

Amazon.com: Apc Av C Type 2 Outlet Wall Mount Power Filter, 120V: Electronics

Thanks for the link. Reasonable price, too.
I'm electronically challenged and appreciate all the help I can get.

 

[chad22]

Whenever I use a generator I never used a ground rod for it. Never really seen a need too.

Most times I use it it's sitting on the back of my dads tow truck and I'd always hate to have to use the generator for about an hour or less then go out and re pull the ground rod.

Then other times it's used momentarily when the power goes out.

And I definitely ain't gonna call a licensed electrician to put in a ground rod every time.

It's not rocket science. Get out a hammer and hammer that rod in the ground. lol

Chad

 

[grsthegreat]

per NEC (Nat Electric Codes) codes, only a permanently installed generator needs a grounding rod installed. Not necessary for portable generator.....ie PORTABLE. Don't need to sweat it. Also as a side note, it can take weeks to months for some ground rods to even function properly. I read a study that showed that in some dry soil conditions, it can take up to 6 months for the ground rods to function properly...something to do with the outside coating on some zinc covered rods to decay enuf for proper grounding.

 

[jonyyuma]

Maybe you ought to read some more of the code book.What year are you reading??? We don't use Zinc coated,but copperclad, some over 8 ft long...and yeap you can put it down with some water for a better readings if you have ground meter, we do..If you wanted real technical IE Portable is under other regulations around here...Just a little more info, but then we are all semi-anonymous folks here, to use someone else's line?

 

[jonyyuma]

Okay, now I need to say, NO matter trying to help someone understand on here. There is always going to be someone deny what you said...It is not nice to kick people. Electrical work is like motor oil as opinions and runs in all directions.Regulations are there to protect the consumer and the innocent kid who walks up and is electrocuted on the spot. And yes, I have carried an ungrounded gen-set around in the back of a truck or front-end loader. I always make sure I have new 3 prong cordset to plug into==OR the fault breaker won't do its job if the tool fails.Carelessness is just as bad as ignorance, except you might have know better. ENUF said ,I will get off the box.

 

[Short Game]

A note to those who power their houses with a portable when the power goes out: to protect the guys and gals who come out in that storm to get your power back on for you, you must break all three legs between the house and the transformer. If you think that just flipping the main breaker protects the outgoing lines, you are wrong. You can give shocks out there in the world by current feeding into the neutral lead.

The way I dealt with it is, I power only two light and outlet circuits when the power is down for extended periods. I don't run my shop, heat, or refrigerate with the portable. I do run all my lights and electronics (don't want to miss the big game).

What I did was connect the two circuits' romex to a split duplex outlet next to my breaker box. I put three pronged plugs on each of the romexes going on to those two circuits. They are plugged into that duplex under normal circumstances. When I'm on the generator, I pull the two light/outlet circuit plugs from the temporarily dead house power duplex, and plug them into a ganged duplex on the cable coming in from the generator. Under these conditions, I'm relying on the genset's own breakers.

Our PUD line folks are great heroes of mine. They get out there in all conditions and at all hours. I don't want them to get any shocks from me. They have told me they appreciate this.

 

[grsthegreat]

Maybe you ought to read some more of the code book.What year are you reading??? We don't use Zinc coated,but copperclad, some over 8 ft long...and yeap you can put it down with some water for a better readings if you have ground meter, we do..If you wanted real technical IE Portable is under other regulations around here...Just a little more info, but then we are all semi-anonymous folks here, to use someone else's line?

Just look at article 250.34(a) The frame of a portable generator shall not be required to be connected to a grounding electrode...bla bla bla...under following conditions
(1) GEN SUPPLIES ONLY EQUIPMENT MOUNTED ON THE GENERATOR, CORD AND PLUG CONNECTED EQUIPMENT THROUGH RECEPTICLES MOUNTED ON GENERATOR....


enough said. Ive been doing this for 30 years.

The ONLY time you need to use a grounding rod is if the generator is part of a separately derived system AND perminantly mounted.

If the generator is powering a drill, motor, etc wired to the installed outlet......it does not need a ground rod.

 

[grsthegreat]

ALWAYS use a generator transfer switch if powering up to a house panel. The voltage that can go back thru the overhead lines can kill a lineman.

 

[Inspector507]

Just look at article 250.34(a) The frame of a portable generator shall not be required to be connected to a grounding electrode...bla bla bla...under following conditions
(1) GEN SUPPLIES ONLY EQUIPMENT MOUNTED ON THE GENERATOR, CORD AND PLUG CONNECTED EQUIPMENT THROUGH RECEPTICLES MOUNTED ON GENERATOR....

That's what MY code book says too grsthegreat. As usual, you're right.

 

[grsthegreat]

That's what MY code book says too grsthegreat. As usual, you're right.

gee......i wish i could hear my wife say that...just once hehe:laughing:

 

[sailfast]

If you want your UPS or line conditioner to be fully functional, you MUST have a good ground. --> Ground Rod

The more expensive UPS will have indicator lights or status displays for ground faults.

 

[Genermatorman]

The purpose of the ground rod is to prevent there from being any difference in potential between the grounded generator output conductors and the Earth ground. Typically the grounded generator conductor is also bonded to the generator frame. That being the case, if your alternator had some problem in the windings and the genset frame was not connected to the Earth ground by a grounding electrode of some type you might see a higher voltage between an ungrounded generator output conductor and the Earth ground than between an ungrounded generator output conductor and the grounded generator output conductor. The difference in potential would be realized when you touch the generator frame with your bare hand while touching the Earth with your feet. You would become a better path to ground.....zzzzt. If you drive a ground rod and connect it to the genset frame that is already connected to the grounded generator output conductor you have bonded the frame to the Earth so there can exist no difference in potential between them. I am not an engineer but I cannot see this having any effect on breaker or ground-fault circuit interrupting devices. The breakers are tripping based on instantaneous or long term current wherever it goes and the GFCID's are measuring how much current goes out from the ungrounded conductor and how much comes back in on the grounded conductor and tripping when the difference reaches a setpoint of x milliamps. Remember the ungrounded conductor is the hot one, the grounded conductor is the return and the grounding conductor is used to bond conductive materials to the grounded conductor at the electrical service entrance to prevent your stove or dryer or refrigerator shell etc from becoming energized due to an ungrounded conductor coming into contact with it. If contact is made a short-circuit will result in a blown fuse or tripped breaker instead of the metal shell setting there energized and waiting for you to complete the circuit by touching it with one hand while your bare feet are on your concrete floor. Gotta Love it!

 

[danspartan]

In last week's Philly massive power outage, I put my little (3000W) generator to the test.

Generator to power surge strip to extension cords. I ended up wiring it to my furnace by:

1. broke furnace connection at a junction box. (I disabled the furnace breaker 1st)
2. wired a male cord/plug to the furnace wiring.
3. I did nut the furnace, my cord, AND the main house panel ground together (with thought of grounding the generator-should be same as any ground?)
4. I capped the hot and neutral lines coming from the main box (and kept the furnace breaker OFF).
5. plugged furnace into extension cord from fired up generator

Everything ran great through the outage (3 days). Kept furnace and sump on full time, rotated around to freezer, fridge, and even an old school TV to watch the news on occasion.

All sound Kosher? Only point of contact with the house electrical was through that ground connection.

I don't remember seeing anyone's generator around town grounded other than sitting on their driveway or concrete porch.

 

[newbury]

Well since this subject has come up again -

You can probably get by without a ground rod. BUT

I taught Army soldiers to run 10KW to 15KW generators from about 1995 to 2011. They and the vehicles they are connected to are ALWAYS supposed to be grounded.

We had two prime methods of grounding - a 6' or 8' copper rod and the Surface Wire Grounding Kit. The kit consisted of 15 metal stakes connected by 3/16 steel cable.

Since most of our deployed units were in dry desert areas we emphasized moistening the soil often with a saline solution. Usually achieved by filtering water thru the body
/edit - NOT when the generator is running

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA311375

 

[arlen4720]

danspartan DID have a ground rod in this case...he was tied into the building ground system.

 

[bdog]

My current generator has over 3000 hours on it powering my portable office trailer that contains over 100k of computers. I have never used a ground rod. The generator is an inverter and I have a heavy duty battery back up system in the trailer.