Home Generators

dmccarty · Sep 22, 2009

Highbeam said:
.... The genset itself just sets out there with the twistlok hooked to it. No seperate ground rod for a chassis ground. Is that needed? It wasn't part of my inspection. Why would it be needed?

I will be danged if I know WHY its needed by my DR Mower generator attachment said it should have a ground. So I bought two 8 feet long very expensive copper ground rods. One was pounded in near my back panel where the generator would operate and they other back by the barn.

Pounding two 8 feet ground rods into my rocky ground was not fun.

Our power went off last night at 1:13 am. I heard boom from a transformer and then UPSes started beeping. After the system and UPSes were delt with I tried to go back to sleep. But then then power trucks woke me up. They were a mile or so away but I could hear them since our windows were open. Beep Beep Beep they went.

VERY GLAD TO HEAR THEM!

I figured a tree had fallen for some reason but this morning I saw nothing. I have no idea why the power went. The said it would be back on in two hours and it was.

Course when the power came back on things started beeping which woke me up again.

But that is a good thing to wake up for!

Later,
Dan

MossRoad · Sep 22, 2009

dmccarty said:
I will be danged if I know WHY its needed by my DR Mower generator attachment said it should have a ground. ...

I was wondering that, too. Looking at my generator, it is isolated from the frame of the unit with rubber and springs, so it is not really touching the earth even if the frame is in dirt. The manual says to ground it, so I ground it when at home. I grounded it at my in-laws' house when we used it there, too.

You gotta wonder how many folks actually ground their portable generators? You see folks using them all over the place during storms and contractors never seem to ground them, either.

I just suppose it is a good practice to ground it properly in case something would go wrong so there is a good path to ground through the rod instead of someone's body.

QueBota · Sep 22, 2009

I ground my generator also, drove the standard copper rod into the ground next to the generator and connected from the ground screw on the generator to the grounding rod with the standard copper grounding wire and clamp. I even ocassionally clean the clamp/grounding rod connection. Don't know how it could happen but I don't want to be the path of least resistance, my generator puts out 50 amps at 240v.

Funny thing though, my service panel doesn't appear to have a similar ground. There is no copper rod near my service entrance connected with a grounding wire. Both my phone and cable companies use my cold water pipe as a ground which is interesting because my water pipe transitions to black ABS on the well side of the pressure tank.

Dave

Highbeam · Sep 22, 2009

I have two 8' ground rods near and connected to the panel and then my generator is attached to the house panel with a 4 wire connection including neutral and ground that both connect with the panel grounds of course. So my genset is attached to the panel and it's ground but inside the genset if neither the white or ground wire are ever attached to the chassis of the genset (maybe this is described as a "floating neutral") then the genset isn't really grounded.

Think of all the RVs out there equipped with gensets. Those things aren't grounded at all and have 110 volt AC plugs on the outside with GFCI outlets!

So many confusing issues. I got my generator installation inspected, did you?

QueBota · Sep 22, 2009

I don't have an "official" county granted inspection stamp on my service panel, but one of my shooting buddies is an electrician (industrial) and he looked over my setup and said it was more than adequate and safe. I can sleep soundly (between refueling and checking the oil) when running on generator power.

Where I live in the Peoples Rebublik of Maryland you want the government involved in your life as little as possible and they will try to worm their way in given the slightest opportunity.

A friend of mine wanted to remove an old fuel tank from the ground behind his house (they brought natural gas to his area). I told him we could dig it out and get rid of it no problem. He wanted to make sure he followed procedure. The procedure ended up costing him nearly $10K.

Dave

Dargo · Sep 22, 2009

Can anyone give me a layman's explanation of the 'floating ground' that most generators have? I can't really grasp exactly what it is and how to be sure to not fry things in my home due to it. About the only thing I do know is that without proper setup it will destroy about everything in your home that is plugged in and has any transformer in it. My BIL pulled his main and backfed his home through a 30 amp welding outlet. All sorts of things started smoking in his home and he destroyed the circuit board in 4 TV sets, blew the transformers in both of his home furnaces and smoked about everything else that was plugged in. He turned it into his homeowner's policy and got some money but I think he said he ended up being out about $4000 by the time it was all said and done. I know he still has several ceiling fans that don't work and he hasn't replaced yet.

All I know is that I don't want to do whatever he did. So, based on 'a little knowledge being dangerous', I opted to buy a couple hundred bucks worth of extension cords and just use the panels on my little gas powered generators when my power was out last winter. Heck, I didn't even have hot water until I plugged my tankless water heaters into an extension cord with power. I'd forgotten about them needing electricity. My dad found out that his new water, with a tank, also had to have power because it is one of those new ones that doesn't have a pilot flame and uses an ignighter of some sort to fire up.

MossRoad · Sep 22, 2009

Dargo said:
Can anyone give me a layman's explanation of the 'floating ground' that most generators have? I can't really grasp exactly what it is and how to be sure to not fry things in my home due to it. About the only thing I do know is that without proper setup it will destroy about everything in your home that is plugged in and has any transformer in it. My BIL pulled his main and backfed his home through a 30 amp welding outlet. All sorts of things started smoking in his home and he destroyed the circuit board in 4 TV sets, blew the transformers in both of his home furnaces and smoked about everything else that was plugged in. He turned it into his homeowner's policy and got some money but I think he said he ended up being out about $4000 by the time it was all said and done. I know he still has several ceiling fans that don't work and he hasn't replaced yet.

All I know is that I don't want to do whatever he did. So, based on 'a little knowledge being dangerous', I opted to buy a couple hundred bucks worth of extension cords and just use the panels on my little gas powered generators when my power was out last winter. Heck, I didn't even have hot water until I plugged my tankless water heaters into an extension cord with power. I'd forgotten about them needing electricity. My dad found out that his new water, with a tank, also had to have power because it is one of those new ones that doesn't have a pilot flame and uses an ignighter of some sort to fire up.

Hmmmm.... the only time I've seen stuff smoke is when it is over voltaged. Like when two legs of 110 get stuck onto each other and feed 220 to 110 machines. That happened twice to some friends of ours... their drunken neighbor twice in a year backed into a power pole guy wire and somehow pushed two legs of 110 together on the wires that feed both houses. The lights in the house got REAL BRIGHT and about everything in the house got fried!!!

Twice in one year!!! They got new appliances and electronics both times.

My 1st guess is your BIL somehow fed both 110v legs of the generator onto one leg of the 220v welder outlet. That would send 220V down one side of the breaker panel and fry everything connected on that side of the panel. But, that is just a guess.

My other guess is he backfed the welder outlet correctly, but something else was also connected to a 220V circuit somewhere in the house that somehow connected both sides together. What would do that, though?

Dargo · Sep 22, 2009

MossRoad said:
Hmmmm.... the only time I've seen stuff smoke is when it is over voltaged. Like when two legs of 110 get stuck onto each other and feed 220 to 110 machines. That happened twice to some friends of ours... their drunken neighbor twice in a year backed into a power pole guy wire and somehow pushed two legs of 110 together on the wires that feed both houses. The lights in the house got REAL BRIGHT and about everything in the house got fried!!! Twice in one year!!! They got new appliances and electronics both times.

My 1st guess is your BIL somehow fed both 110v legs of the generator onto one leg of the 220v welder outlet. That would send 220V down one side of the breaker panel and fry everything connected on that side of the panel. But, that is just a guess.

My other guess is he backfed the welder outlet correctly, but something else was also connected to a 220V circuit somewhere in the house that somehow connected both sides together. What would do that, though?

I certainly can't say for sure what he did. I just saw things start smoking and immediately smelled that burning electronics smell. While he was literally wondering out loud what was wrong I ran out his front door and flipped his generator off. I wasn't there when he wired it up and I wasn't there after the magic smoke leaked out of his stuff. My contribution was bringing him a five gallon can of gas for his generator. He lives on a road that dead ends down a long hill and they didn't have anything that could get out to get gas so I was only the gas delivery guy. He later said something about not accounting for the floating ground. An electrician I am not. I've done the very basic stuff like wiring my barns but that was pretty well limited to installing the breaker box, running some outlets, dropping a 220v down from the box for my welder and wiring in a couple of light switches. I'm still in basic wiring 101 as far as my skill and knowledge level.

ultrarunner · Sep 23, 2009

dpdee13 said:
Funny thing though, my service panel doesn't appear to have a similar ground. There is no copper rod near my service entrance connected with a grounding wire. Both my phone and cable companies use my cold water pipe as a ground which is interesting because my water pipe transitions to black ABS on the well side of the pressure tank.

Dave

Not every home has a ground or even a service or circuit panel...

I worked on a few older homes in my city from the 1920's and they have zero in the way of grounding...

Back then the service drop was knob and tube that went to a double knife switch that disconnected both the hot and neutral... the knife switch is exposed in a wooden box and not protected by a panel box and is between the service drop and meter.

A lot of these 30 amp Edison Fuse Services still exist...