Generator question

BigWaylon

BigWaylon

Head philatelist
Staff member
2A Bourbon Hound 2024
2A Bourbon Hound OG
Charter Life Member
Benefactor
Supporting Member
Multi-Factor Enabled
Joined
Dec 18, 2016
Messages
64,679
Location
Charlotte
Rating - 100%
71   0   0
I have my eye on something, but don’t actually know when I’d ever use it. So I’ll explain a little and if anybody thinks of a situation I’d use it, please share.

I have two of the 3000/3500 HF Predator Inverter generators. I have two outlets wired to my house, so that I can hook them both up and basically run my whole house except for 240V (220, whatever the correct term is). That means I’m just out A/C, oven and electric dryer.

Plenty other options to cook with, gas heat and hot water, and multiple drying racks. Have an attic fan, five ceiling fans, a window unit A/C and a portable A/C. So far, never really had an issue without power being out.

But I’ve always been disappointed HF only offered a parallel kit for dual 2000W generators, and not for the 3500W model. Years ago they said it was coming, and nothing. Happened to check recently and they now exist.

www.harborfreight.com

RV Ready 50 Amp Inverter Generator Parallel Kit

Amazing deals on this 50Amp Inverter Generator Parallel Kit at Harbor Freight. Quality tools & low prices.
www.harborfreight.com www.harborfreight.com

039C1830-84BF-4AA2-AADC-29C7D0ED0C77.jpeg

You end up with a 50A RV outlet, but everything is still 120V. Mine do come with RV adapters, but I don’t have an RV.

I can’t come up with a scenario when having one 50A 120V outlet would be used. I’d obviously still have both generators there, so why not just have two 30A sources? I have homemade cords that plug in to them and give me six outlets each, should I need them.

The whole reason I originally bought two was to put one on the back deck and one in the garage (with the door open) and run extension cords as needed. Or if my mom’s power was out I could loan her one to keep fridge/freezer alive. I’ve even taken to her house to power an electric turkey dryer at Thanksgiving.

They’re really quiet, and having two is kinda handy. Yeah, it would be nice to have one 12,000 and run the whole house, but that’s not the route I took.

So…anybody think of a scenario I’m missing where the parallel kit would be useful? It’s only $70, but I’m not sure I’d ever use it.
 
I don't see where you would benefit. You can't (or shouldn't) plug any power source into a wiring system that has a capacity lower than the source. So don't plug a 30 amp source into your 15 amp residential receptacle circuit for example. Those 3kw units probably do 25 amps each. Be careful you don't overload your receptacle circuit.
 
Last edited:
Bezep1 said:
Yes it's illegal to connect to the utility without a UL listed device
Click to expand...
Perhaps I misread the original post. I read he has two outlets wired to his house and he hooks up his generator powering the house 'backwards' as in the current flow is outgoing from the house as opposed to incoming from the utility. I didn't see anything about isolating the house from the grid with a transfer switch.
 
They way you have it now is the best scenario IMHO. If 1 quits you still have 1. And the cost to rewire yet again. You can even pick and choose which side is powered now.
71Ragtop said:
Do you have a cut out switch on that so no generated power isn't being fed back out the SEC?
Click to expand...
Of course he does.
 
71Ragtop said:
Perhaps I misread the original post. I read he has two outlets wired to his house and he hooks up his generator powering the house 'backwards' as in the current flow is outgoing from the house as opposed to incoming from the utility. I didn't see anything about isolating the house from the grid with a transfer switch.
Click to expand...
It's wired to avoid that
 
Bezep1 said:
I don't see where you would benefit. You can't (or shouldn't) plug any power source into a wiring system that has a capacity lower than the source. So don't plug a 30 amp source into your 15 amp residential receptacle circuit for example. Those 3kw units probably do 25 amps each. Be careful you don't overload your receptacle circuit.
Click to expand...
The two receptacles on the house are 30A, just like the generator. Yes, it says don’t run more than 25A through them.

I wasn’t even looking for a benefit with my current setup. I was trying to think outside my house where it might be handy, like an RV. Just couldn’t come up with a scenario where I’d want to have one 50A circuit.
 
LeeMajors said:
They way you have it now is the best scenario IMHO. If 1 quits you still have 1. And the cost to rewire yet again. You can even pick and choose which side is powered now.
Click to expand...
My reply above this would also fit as a response to you.

I’m looking to see if I’m missing somewhere other than my house where the single 50A circuit would be useful.
 
BigWaylon said:
My reply above this would also fit as a response to you.

I’m looking to see if I’m missing somewhere other than my house where the single 50A circuit would be useful.
Click to expand...
Unless you are buying an rv or would ever loan them to someone with one.
The hearts and hammers may borrow them at some point.
 
LeeMajors said:
Unless you are buying an rv or would ever loan them to someone with one.
The hearts and hammers may borrow them at some point.
Click to expand...
Yeah, that’s where my head is. Better to have to two separate units to spread out as needed. Was curious if I was just missing an obvious scenario. Sounds like I’m not.
 
My concern is you run both generators simultaneously w/o the parallel kit is that you’re mixing two neutral circuits from two different generators onto one neutral buss in your load center. Each generator would feed one leg of your 240 load center, but they would share a common neutral. I don’t think that is a good idea…

The only benefit that I could see for having a 50A 120 circuit is if you moved all of your critical circuits onto one leg of your load center, and then powered that leg from the 50A parallel kit. However, the drawback to this is that you may not be balanced across both legs of incoming power the rest of the time.

No matter what, if you want to utilize both generators simultaneously I’d Definately use some type of parallel kit so as to synch up the cycles and neutral’s.
 
Couldn't you just tie the two generator grounds together? It's basically being done now through the neutrals and ground bar at the panel board.
 
Personally, I've never been keen on the whole house generation concept. Sure, it's nice having a big generator and lots of fuel and you can pretend nothing is going on in the outside world. But, my philosophy is if you need a genset then things aren't normal. We have a power conservation mode, where if the outside power goes out, we only power up what is necessary, including minimal lights and alternative heating/cooling. The idea is to conserve fuel consumption, because we don't know how long we'll have to run that way. I don't think in hours, I think in days. And what if I can't resupply fuel? How many days or hours do you have?
So, I prefer the multiple generator concept for redundancy and scalability. You can run as few or as many as you need and to different areas instead of one great big unit that consumes fuel, even if you're not using all the power generated.
No, I can't think of a need for a 50A circuit in a power down scenario.
 
Bezep1 said:
Couldn't you just tie the two generator grounds together? It's basically being done now through the neutrals and ground bar at the panel board.
Click to expand...
Unfortunately no.

Our alternating current electricity ( in the USA) changes direction (cycles) 60 times a second (60 hertz). When multiple generators feed a common load center, there needs to be a way to syncronize these cycles. Same holds true if you have your own solar power system that is hooked into the grid. The cycles of what you’re producing need to be phased to the cycles of the grid.

What parallel kits do is syncronize the two generators together so that they are operating on the same frequency. If you don’t have a parallel kit and feed two generators into the split phase on a 120/240 system, the neutrals will be out of synch, to say the least.
 
BigWaylon said:
I’m not trying to power anything with 240V.
Click to expand...
Understood, but if you feed one 120V leg of your load center from one generator, and the other 120V leg from a different generator - you're sharing a common neutral inside the load center, and that neutral is wired to two different generators that are not in phase.

Even if you synch the generator phased up with a parallel kit, you will need to turn off any 240V breakers in the panel before hooking the generator up so that you don't blow the generators by accidentally backfeeding them from the 240 equipment (such as a water heater). 240 electric motors and induction heaters (range, stovetop, etc) does not require a neutral; the current alternates between the two different 120V legs. So you'd be backfeeding generator 1 from generator 2 - not a good thing.

My advice is that you don't try to feed your load center with two different generators - parallel kit or not. You may end up with some fried electronics - or fried generators.
 
Again. I’m not asking anything about the way I’m currently powering my house. I’ve used it multiple times with no issues for years.

Yes, there’s an interlock kit.
No, none of the 240V breakers are on when they’re running.

All I was intending to ask if there’s some reason, NOT ATTACHED TO MY HOUSE, that I would want a single 50A receptacle instead of two 30A receptacles.

It sounds like there’s not anything I wasn’t thinking of.
 
Scsmith42 said:
Unfortunately no.

Our alternating current electricity ( in the USA) changes direction (cycles) 60 times a second (60 hertz). When multiple generators feed a common load center, there needs to be a way to syncronize these cycles. Same holds true if you have your own solar power system that is hooked into the grid. The cycles of what you’re producing need to be phased to the cycles of the grid.

What parallel kits do is syncronize the two generators together so that they are operating on the same frequency. If you don’t have a parallel kit and feed two generators into the split phase on a 120/240 system, the neutrals will be out of synch, to say the least.
Click to expand...
I respectfully disagree. Two power sources can be at the same reference point and have completely different voltages. As long as there is no interconnection of the other pole, no problem. In this case, the 240 VAC loads may see something strange, since the outputs will be out of synch, but technically speaking there is no problem with connecting one side (neutral or ground). This is evidenced by the fact that he is doing it now. The point of connection is the neutral/ground bar in the panelboard.
 
You must log in or register to reply here.
Back
Top Bottom