Is your stand by gen-set grounded?

[dlundblad]

I think you’re technically supposed to add a ground, but nobody ever does as they’d all be connected. Code is 2 8’ rods at least 6’ apart bonded with a continuous wire on a new service.

The ground rods now need to be connected to transfer switch since that’s now the first means of disconnect. (A lot of times, that wire is too short to reach disconnect.) Ground from generator to transfer switch. The main panels grounds need to be be connected to transfer switch ground bar as well. The house’s main panel is now a subpanel and needs to have the grounds and neutrals separated as well as the green bonding screw removed.

You’re achieving the same results if you leave the main ground in the house’s panel and just run a wire from the main panels ground bar to the disconnects ground bar. The main this is the grounds and neutrals separated.

 

[dlundblad]

I can run my well pump off a 1500W inverter. Have to use a step-up transformer to convert the 120V to 240V. It's a variable speed pump.

Interesting. How many amps does the transformer create?

 

[ka9mnx]

The only time you ground the generator is if it's used as a stand alone unit. Like running an RV. Once you use it to power your home, or anything connected to the mains, you NEVER ground the generator. The NEC only wants to see a single point ground at the service entrance.

 

[Pablo]

Interesting. How many amps does the transformer create?

It must have a tiny pump. Shallow well or cistern. It's possible.

https://plumbinglab.com/how-many-amps-does-a-well-pump-use/

 

[dlundblad]

It must have a tiny pump. Shallow well or cistern. It's possible.

https://plumbinglab.com/how-many-amps-does-a-well-pump-use/

I asked what the transformer created since his 1500w generator would only creat 12.5 amps.

 

[Pablo]

I asked what the transformer created since his 1500w generator would only creat 12.5 amps.

Exactly. I know, I was just showing some small variable speed pumps don't draw as much as mine, for example - especially at start up.

 

[brianl703]

Interesting. How many amps does the transformer create?

It's a 3kVA transformer.

The well is 260 feet deep and the well pump is a variable speed Grundfoss SQE pump. Which uses about 800W with one faucet running.

The controller for the well pump has a pressure sensor and the controller adjusts the pump speed to maintain the set pressure (70PSI).

 

[ollie]

The NEC only wants to see a single point ground at the service entrance.

I think you are confusing the neutral grounding. Any generator backup or otherwise has to be grounded separately by an 8' ground rod per code. This is especially important if you are hooked to an automatic transfer switch with a switched neutral connected.

Only reason I know this is because I have set up numerous back up and temporary systems and have not been signed off until a separate ground was in place. Strange things happen when you share grounds with home systems. One of the most common is getting shocked by the water spigots on older homes when water pipes were used for grounding panels.

 

[brianl703]

I think you are confusing the neutral grounding.

You are NEVER to connect neutral and ground together downstream of the service disconnect. They are to be connected together in exactly one place.

 

[ka9mnx]

I think you are confusing the neutral grounding. Any generator backup or otherwise has to be grounded separately by an 8' ground rod per code. This is especially important if you are hooked to an automatic transfer switch with a switched neutral connected.

Only reason I know this is because I have set up numerous back up and temporary systems and have not been signed off until a separate ground was in place. Strange things happen when you share grounds with home systems. One of the most common is getting shocked by the water spigots on older homes when water pipes were used for grounding panels.

Must be a California thing. The "ground" is a safety ground and the NEC only wants one safety ground. At the service panel. Also, it is very unwise to switch the neutral at the transfer switch.

 

[brianl703]

Must be a California thing. The "ground" is a safety ground and the NEC only wants one safety ground. At the service panel. Also, it is very unwise to switch the neutral at the transfer switch.

It's not unheard of for inspectors to require things that the NEC does not, and they'll continue to do it out of ignorance till an electrician dares to challenge them on it.

 

[ollie]

You are NEVER to connect neutral and ground together downstream of the service disconnect. They are to be connected together in exactly one place.

Where did I say this? I'm speaking strictly of a switch neutral connected in terms of an automatic transfer switch application. Article 250/Table 250.66 outlines the grounding requirements. It is written in such a way as to leave it to the discretion of the inspector signing off. When I was in the industry I just grounded every generator with an 8' rod and used a switched neutral on every singe transfer switch I set up. Hell I even grounded transformers. Nothing wrong with using extra precautions when doing electrical installs.

 

[brianl703]

Where did I say this? I'm speaking strictly of a switch neutral connected in terms of an automatic transfer switch application. Article 250/Table 250.66 outlines the grounding requirements. It is written in such a way as to leave it to the discretion of the inspector signing off. When I was in the industry I just grounded every generator with an 8' rod and used a switched neutral on every singe transfer switch I set up. Hell I even grounded transformers. Nothing wrong with using extra precautions when doing electrical installs.

You said, "
Strange things happen when you share grounds with home systems. One of the most common is getting shocked by the water spigots on older homes when water pipes were used for grounding panels."

Only way that happens is when someone has connected neutral and ground together downstream of the service disconnect. A proper generator installation WILL have the neutral/ground bonding jumper removed and it WILL have a separate neutral and ground wire coming from the generator, which will require at least a 4-conductor feeder (5 conductor for 3-phase).

 

[spasm3]

I back feed my breaker panel with a 14-50 4 prong plug, with a neutral. I shut off the main breakers when doing this. Should i remove the neutral bond on the generator , since i'm using the house ground?

If i understand the posts correctly, i could have neutal current flowing to my generator frame, so i should unbond it. Yes?

 

[brianl703]

I back feed my breaker panel with a 14-50 4 prong plug, with a neutral. I shut off the main breakers when doing this. Should i remove the neutral bond on the generator , since i'm using the house ground?

If i understand the posts correctly, i could have neutal current flowing to my generator frame, so i should unbond it. Yes?

Yes. If you check your generator plug with a multimeter, you should measure no continuity between the ground and neutral prongs. And you should measure continuity between the ground prong and the generator frame.

 

[ollie]

You said, "
Strange things happen when you share grounds with home systems. One of the most common is getting shocked by the water spigots on older homes when water pipes were used for grounding panels."

I see my bad at explaining it.

 

[ollie]

You are NEVER to connect neutral and ground together downstream of the service disconnect. They are to be connected together in exactly one place.

Brian, Let's see if I can explain this in easy to understand terms. Bonded ground/neutral at source and "upstream" is OK. After it goes past the panel then it's a floating ground. You will have to excuse me as I have been out of the temporary power industry over 20 years.

I do know how to set up a generator hands on and go beyond code requirements. Explaining it, not so good.

 

[brianl703]

Brian, Let's see if I can explain this in easy to understand terms. Bonded ground/neutral at source and "upstream" is OK. After it goes past the panel then it's a floating ground. You will have to excuse me as I have been out of the temporary power industry over 20 years.

I do know how to set up a generator hands on and go beyond code requirements. Explaining it, not so good.

Yes, that's correct. Worth noting also that dryers and ranges are too often installed with a 4-wire cord and the neutral/ground bonding jumper not removed.

 

[ollie]

What's gaining popularity are the natural gas stand by generators. With automatic switching gear they are pretty much seamless.

 

[andyd]

Yes. If you check your generator plug with a multimeter, you should measure no continuity between the ground and neutral prongs. And you should measure continuity between the ground prong and the generator frame.

Thank you. That's an easy thing to check.The generator is a portable. I have an inter lock on the main and the 2pole breaker directly below it that is wired to an outside L6-30 Socket, Cable is 12/3 SO