Generator tie in questions

[Box of frogs]

Need help from someone who has already done this or from a wire nut (electrician)

I bought a gas generator to use here at the homesite if we lose power. I am ~1/2 mile from the main road and the only house on this leg of the power pole. I will most likely be without service for a long time during a ice storm or if a tree falls over my power drop.

I sized it to run the fridge, washer, some lights and few small appliances. Checked the amp draw on the fridge and used a online calculator to figure out the rest.I bought a portable 6500W start up and 5500W idle output generator and I want to feed it into the existing breaker panel to use during outages.

Questions are;
Per the state code I have to put a interlock on the breaker panel so that the MAIN and the breaker for the generator can't both be on at the same time. This is so we don't back feed power down the line and kill a lineman. I'm fine with that part and can install the interlock myself.

1) the breaker for a 6500w generator should be 50 amp and 5500W should be 40amp (using online calculator for this)- do I size the breaker input for start up amps or for idle amps?

2) Since the generator has its own circuit breaker is the breaker I install in the panel to tie the generator into really just a switch or does the breaker sizing matter that much.

3) I planned to hard wire in 8 gauge wire initially but now I am finding 10 gauge wire with ends already on them, is 10 gauge going to be enough?

4) The existing plug in on the generator to use the pre-made cable is 240v. I sized everything using 120v is this going to matter when I'm using the generator to feed power into the home breaker panel?

Im grateful for help, thanks in advance.

BoF

[BucketBack]

My interlock is to pull the main, then fire it up. I'm too cheap to feed the power companies line.

A Korean era SeaBee set it up .

[BucketBack]

Wrong forum

[Slippy]

Somewhere on the OTP is a thread about the transfer switch that I had my electrician install.

Need help from someone who has already done this or from a wire nut (electrician)

I bought a gas generator to use here at the homesite if we lose power. I am ~1/2 mile from the main road and the only house on this leg of the power pole. I will most likely be without service for a long time during a ice storm or if a tree falls over my power drop.

I sized it to run the fridge, washer, some lights and few small appliances. Checked the amp draw on the fridge and used a online calculator to figure out the rest.I bought a portable 6500W start up and 5500W idle output generator and I want to feed it into the existing breaker panel to use during outages.

Questions are;
Per the state code I have to put a interlock on the breaker panel so that the MAIN and the breaker for the generator can't both be on at the same time. This is so we don't back feed power down the line and kill a lineman. I'm fine with that part and can install the interlock myself.

1) the breaker for a 6500w generator should be 50 amp and 5500W should be 40amp (using online calculator for this)- do I size the breaker input for start up amps or for idle amps?

2) Since the generator has its own circuit breaker is the breaker I install in the panel to tie the generator into really just a switch or does the breaker sizing matter that much.

3) I planned to hard wire in 8 gauge wire initially but now I am finding 10 gauge wire with ends already on them, is 10 gauge going to be enough?

4) The existing plug in on the generator to use the pre-made cable is 240v. I sized everything using 120v is this going to matter when I'm using the generator to feed power into the home breaker panel?

Im grateful for help, thanks in advance.

BoF

[hawgrider]

SPARKYPREP is the OTP electrician he'll probably pop in here.

He helped me out on the temporary electric pole 200A service I put together at my son-in-laws deer camp.

[Dwight55]

Need help from someone who has already done this or from a wire nut (electrician)

I bought a gas generator to use here at the homesite if we lose power. I am ~1/2 mile from the main road and the only house on this leg of the power pole. I will most likely be without service for a long time during a ice storm or if a tree falls over my power drop.

I sized it to run the fridge, washer, some lights and few small appliances. Checked the amp draw on the fridge and used a online calculator to figure out the rest.I bought a portable 6500W start up and 5500W idle output generator and I want to feed it into the existing breaker panel to use during outages.

Questions are; OK . . . here we go
Per the state code I have to put a interlock on the breaker panel so that the MAIN and the breaker for the generator can't both be on at the same time. This is so we don't back feed power down the line and kill a lineman. I'm fine with that part and can install the interlock myself.

1) the breaker for a 6500w generator should be 50 amp and 5500W should be 40amp (using online calculator for this)- do I size the breaker input for start up amps or for idle amps? Using the 6500 watt gen at 120 volts is 54 amps . . . that means a 60 amp circuit breaker . . . 5500 watts at 120 volts is 46 amps . . . that means a 50 amp breaker . . . but you need to size it for the 6500 so it won't trip during a large startup

2) Since the generator has its own circuit breaker is the breaker I install in the panel to tie the generator into really just a switch or does the breaker sizing matter that much. Yes . . . the sizing matters . . . too large and it won't protect . . . too small and it will constantly trip under heavy load

3) I planned to hard wire in 8 gauge wire initially but now I am finding 10 gauge wire with ends already on them, is 10 gauge going to be enough? Absolutely not . . . it might work . . . but it is outside of code by a short country mile. If you use copper wire . . . you need AWG 6 . . . aluminum . . . you need AWG 4. Outlaws can use the smaller wire . . . but when the place burns down . . . it's just "too bad"

4) The existing plug in on the generator to use the pre-made cable is 240v. I sized everything using 120v is this going to matter when I'm using the generator to feed power into the home breaker panel? No . . . most generators are set up so you feed 208 / 220 / 240 volts into the house

Im grateful for help, thanks in advance. I worked as an electrician for 4 1/2 yrs in Uncle Sam's navy . . . and for the next 30 years in civilian life

BoF

May God bless,
Dwight

[Box of frogs]

Thanks Dwight55

[Sparkyprep]

Need help from someone who has already done this or from a wire nut (electrician)

I bought a gas generator to use here at the homesite if we lose power. I am ~1/2 mile from the main road and the only house on this leg of the power pole. I will most likely be without service for a long time during a ice storm or if a tree falls over my power drop.

I sized it to run the fridge, washer, some lights and few small appliances. Checked the amp draw on the fridge and used a online calculator to figure out the rest.I bought a portable 6500W start up and 5500W idle output generator and I want to feed it into the existing breaker panel to use during outages.

Questions are;
Per the state code I have to put a interlock on the breaker panel so that the MAIN and the breaker for the generator can't both be on at the same time. This is so we don't back feed power down the line and kill a lineman. I'm fine with that part and can install the interlock myself.

1) the breaker for a 6500w generator should be 50 amp and 5500W should be 40amp (using online calculator for this)- do I size the breaker input for start up amps or for idle amps?

2) Since the generator has its own circuit breaker is the breaker I install in the panel to tie the generator into really just a switch or does the breaker sizing matter that much.

3) I planned to hard wire in 8 gauge wire initially but now I am finding 10 gauge wire with ends already on them, is 10 gauge going to be enough?

4) The existing plug in on the generator to use the pre-made cable is 240v. I sized everything using 120v is this going to matter when I'm using the generator to feed power into the home breaker panel?

Im grateful for help, thanks in advance.

BoF

1. Use the 40a breaker size. The 50a is considered "inrush current" and will only be experienced for a fraction of a second, therefore the 40a will hold, and you will be properly protected.

2. The breaker size in the panel should be a 40a, and yes, it still matters despite the breaker on the generator.

3. Use the 8 gauge wire. The NEC says that the #8 is rated for 40a, while the #10 is only rated for 30a. If you were to use the #10, you run the risk of the wire burning up before the breaker trips in the event of a fault. When it comes to wire, bigger is better.

4. This is where it gets tricky. Ohm's Law says that when volts go up, amps go down. Wire and breaker size is based on amps, not volts. So, if I am understanding you correctly, you did your calculations based on 120v, but are running 240v out of the generator. This means that your 120v loads will be reasonably split evenly between the two legs of 240v. That means that your 120v calculations will be adequate for the 240v supply. You should be good.

[Box of frogs]

Thanks Sparkyprep

BoF

[Dwight55]

Well . . . what Sparkyprep said . . . is kinda good . . . if you are going to do that somewhere in the backwoods of the south where nobody looks at anything . . . there are no inspections . . . and if it "kinda" works . . . everyone is happy.

The original advice I gave you is up to date . . . will get you thru a "code" inspection . . . Sparky's may . . . and may not . . . depending on the locale and the inspector.

The difference between doing a job right . . . and doing one . . . us usually not that much . . . and I'd suggest you do it "right".

As far as the 120 volt load . . . it depends on how the circuits are set up in the secondary panel. If they are set up correctly . . . you should look for a 60 / 40 split of amperage on the two legs of the 240 volt supply.

If they are not set up correctly . . . you could be experiencing almost the full 5500 watts on one side . . . which would be 45.83 amps . . . which would constantly and consistently trip the 40 amp breaker.

Do it according to code . . . and you will be able to sleep soundly . . . and know you are properly protected.

May God bless,
Dwight