Generators - Backfeeding - 120V

[etpm]

When I wired in my generator sub panel last year I transferred all the circuits I thought I would need. If all the amps are added they exceed by quite a bit the amps my 7500 watt generator will put out. But I have never loaded up the circuits to their breaker rating. I am thinking about buying a 4000 watt generator. My only worry is starting the well if the fridge and freezer are also starting. I think I can get some sort of load sensing device that will prevent the well from starting if the load is too high. Though it may be possible to obviate using this device by using capacitors. The well motor is already a capacitor start motor, or maybe the cap is always in circuit. But I think it's a cap start. Anyway, I remember reading about a scheme used in industrial settings for starting motors when other motors were starting and there was a consequent voltage drop. Capacitors were used as well as relays. I think. It was really a kind of brute force setup the sort of which was common in the mid twentieth century. if anybody reading this has any info I would be happy if they posted it.
Thanks,
Eric

 

[LittleBill21]

When I wired in my generator sub panel last year I transferred all the circuits I thought I would need. If all the amps are added they exceed by quite a bit the amps my 7500 watt generator will put out. But I have never loaded up the circuits to their breaker rating. I am thinking about buying a 4000 watt generator. My only worry is starting the well if the fridge and freezer are also starting. I think I can get some sort of load sensing device that will prevent the well from starting if the load is too high. Though it may be possible to obviate using this device by using capacitors. The well motor is already a capacitor start motor, or maybe the cap is always in circuit. But I think it's a cap start. Anyway, I remember reading about a scheme used in industrial settings for starting motors when other motors were starting and there was a consequent voltage drop. Capacitors were used as well as relays. I think. It was really a kind of brute force setup the sort of which was common in the mid twentieth century. if anybody reading this has any info I would be happy if they posted it.
Thanks,
Eric

your looking for this

https://amzn.to/3nwV2fN

 

[etpm]

your looking for this

https://amzn.to/3nwV2fN

Thanks. That was quick. I really like TBN.
Cheers,
Eric

 

[grsthegreat]

Those SMM Modules only work on 240 circuits. I doubt the 4000 watt gen has 240 output

 

[aczlan]

Those SMM Modules only work on 240 circuits. I doubt the 4000 watt gen has 240 output

I have a 3500 watt Champion that has selectable 120V/240V output (puts out 3500W on either 120V or 240V).
Growing up we had an ancient red Tecumseh powered generator that also had 120/240V outputs.

Aaron Z

 

[grsthegreat]

Good to know, ive never seen 240 outlets below 5000 watt units. Seems kind of useless as it wouldnt even put out 15 amps

 

[MossRoad]

Good to know, ive never seen 240 outlets below 5000 watt units. Seems kind of useless as it wouldnt even put out 15 amps

Our 26 year old Coleman generator is 4200W and has 120/240. Yes, it's 15 amps. That's plenty for our needs. The only 240V items are the air conditioner (which we don't use in power outages) and the well. Everything else is 120v. I manage the loads of the freezer and fridges manually. Most of the house lighting is LED bulbs, so we can run any lighting we might want to when running any of the appliances. We have a wood burning stove, so furnace isn't needed either. We'll be getting a new TV soon, so I'll probably get a UPS/Power conditioner in-line with that.

But in all reality, we get outages fairly often, but they are usually just a few seconds. Several minute long outages are 5-6 a year. Maybe 1 per year average where I'm tempted to fire up the generator, and usually it comes back on before I do.

 

[robstaples]

Pull the plug to a high amperage 220v outlet, like to the dryer or range. Make a jumper plug to put a short across the powered lugs that are normally 220v.

Or, at a high amperage 220v breaker, remove the circuit wires and place a jumper wire across the terminals to feed the other leg. Size the jumper wire accordingly.

This is the best idea. If you forget about the plug, when the utility power is switched back, the breaker will trip with the dead short. Noise might surprise you.

 

[repete]

I have installed generator panels in all the homes I have built. 320 amp service (no CT) with two 40 slot 200 amp panels. The flush mount generator panel is beside those two panels with 12 slots. Super easy to do during construction. I especially like the two watt meters built into the generator panels to see what my load is on either side of the 220 volts.
I also discovered along the line that when you are "charging" the refrigerator, with a frost free freezer, make sure the freezer is not starting the "defrost" mode when you put power to it for 30 minutes...

 

[LittleBill21]

Those SMM Modules only work on 240 circuits. I doubt the 4000 watt gen has 240 output

my 3500 watt unit has a 240 selector.

 

[John_Mc]

Those SMM Modules only work on 240 circuits. I doubt the 4000 watt gen has 240 output

Ran our house for years during power outages with a 4000 watt generator (it had a 6600 watt surge rating). It had both 240 and 120 outputs. It took some load management: I'd leave the well pump turned off until we needed it. When I needed to pump up the pressure tank, I'd just shut off the circuits for the fridge and freezer.

Finally had to replace the old 4KW generator when it took a lightning hit during the construction of our tree house. We went with a 5500 watt (continuous rating) Honda, so I don't have to be quite so careful with the load management.

 

[Sberry]

You cant afford it is no excuse for this cobble job and I am weary of looking for the 1 or 2 people on this thread even call this system by the right voltage.

 

[Sberry]

I know all the instruments on the plane should work correctly but it dont matter because i know where i am going despite the fact i dont know the difference beteeen av gas and jet fuel. We really dont need legal tires on the landing gear cause i cant afford them.

 

[MossRoad]

 

[kwbretired]

On a generator panel, how do you keep the generator from back feeding to all the breakers in the house?

 

[MossRoad]

On a generator panel, how do you keep the generator from back feeding to all the breakers in the house?

Pretty helpful, eh?

 

[MossRoad]

On a generator panel, how do you keep the generator from back feeding to all the breakers in the house?

You should have an on/off/on switch between the generator panel and the rest of the house wiring. That turns off power company power, goes to off, then turns on generator power. It also isolates the generator panel from the home panel so that any circuits not in the generator panel cannot be backfed from the generator.

That's the best, safest way.

You could use an on/off/on switch, a manual transfer switch, and automatic transfer switch, a lockout, etc., but they all perform the same function;

- disconnect power company power.
- go to an off position.
- connect generator power.
That way, the two power sources cannot mix, and cannot backfeed each other.

Absent of one of those devices, the only way would be to turn off the main, and turn off all of the house breakers before starting the generator and select the loads you want to run. And unless you have a good understanding of that, as someone else mentioned, and can guarantee you'll never mess up the sequence, don't do it yourself. You could kill someone including yourself. Have an electrician wire you up a proper transfer option.

 

[mwemaxxowner]

I have a quick question. I have a separate sub panel that services my heat pump.

I've been thinking that, when I get a generator, I want to get a generator input wired up on the house, to a double pole breaker and an interlock kit.

However, since I have that sub panel, a simple interlock will not suffice, right? The main on either panel will shut off the whole house (I believe). So I'm guessing both mains will need to be shut off to feed power to the house, and one interlock does not ensure that.

Just making sure I'm following things correctly.

 

[LittleBill21]

I have a quick question. I have a separate sub panel that services my heat pump.

I've been thinking that, when I get a generator, I want to get a generator input wired up on the house, to a double pole breaker and an interlock kit.

However, since I have that sub panel, a simple interlock will not suffice, right? The main on either panel will shut off the whole house (I believe). So I'm guessing both mains will need to be shut off to feed power to the house, and one interlock does not ensure that.

Just making sure I'm following things correctly.

if the the subpanel is fed off the main panel, you only need one interlock. you only need to shutoff the main breaker, at the panel, that is wired to the pole. this is to stop electricity from flowing out onto the powerlines on the pole.

 

[mwemaxxowner]

I assumed that was the case, until a few days ago I flipped the main on my sub panel to work on my HVAC (fan was frozen with ice) and it shut the whole house off. Since that sub panel had the ability to shut the whole house off I wasn't sure if that meant it feed from the main panel or not.