120v generator and connecting to NEMA 14-50?

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Old 04-18-20, 05:51 PM
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120v generator and connecting to NEMA 14-50?

Updated question:

I should have just phrased my question this was...

1. Can anything happen to the main electrical service panel if both legs are fed by the same 120v source?
2. If both legs are fed by the same source, as if some one had jumped the legs together because they only one leg was hot (This would juice both legs), what would happen to any 220 appliances that might get connected? For example, a well pump, hvac, dryer, or oven, if anything?


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I'm wondering what would happen...

I currently have a Interlock with a NEAM 14-50 outlet to power my service panel when I lose power. My "Portable" Generac GP15000E can power everything without a hitch. The problem is, it's really not portable and it's a bear to get it setup and hooked up. Basically I only use it when power goes out for extended periods of time.

For short outages, up to a few hours, I've been using a Honda EU2000 with extension cords everywhere.. It's just powering TVs, lights, computer stuff and sometimes a fridge.. But I was thinking.

I was thinking I might get a 2nd inverter generator and put them in parallel. This would allow me to use a 120V 30amp RV plug. If I put an adapter on it, it'll split it so I can connect it to my house, but I'm going to end up with 120V, I think it's called in phase, on both legs of my service panel.

Does anyone know what might happen if anything at all? Might it kill my 220 appliances like the dryer or HVAC system or will they simply just not run? This is assuming someone forgets to turn off the 220v breakers of course.

I'd love to do this because these little inverter generators are so easy to move around and I hate running extension cords around the house. I just don't know what might happen, if anything to the electrical panel or anything connected.

Thanks!
 

Last edited by crabjoe; 04-18-20 at 06:24 PM.
  #2  
Old 04-18-20, 08:16 PM
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If you have any multiwire circuits with shared neutral there is potential to overload the neutral.
Paralleling generators requires special circuits to sync them. You would be bettor off to move all the required circuits in your panel around so they are on the same leg and can be fed from 120 only.
 
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Old 04-18-20, 08:30 PM
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I'm not sure how it might overload the neutral on the generator(s). Once parallel, they're acting as one generator. They'll send out 30 amps on 1 30amp 120v plug. That'll get passed to both legs of the electrical main. Regardless of which leg a load is on, the generators won't know the difference.

What I'm trying to find out is if someone forgot to turn off the 220v breaks in the panel, if it might cause any damage to the appliances connected to those 220c breakers, since each leg won't be 180 degs a part.
 
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Old 04-18-20, 10:28 PM
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Since you want to connect both legs of the 240v service together..... nothing will happen to the 240v only appliances. Anything labeled as 120/240v...... like a range or dryer.... could partially run as their electronics typically run off of 120v. but they won't be damaged.
 
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Old 04-18-20, 10:50 PM
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You don't overload the neutral on the generator. You could overload any circuits in the panel that share the neutral.
 
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Old 04-19-20, 12:15 AM
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@joed Can you actually overload a neutral in the main when it's bonded to the ground?
 
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Old 04-19-20, 05:35 AM
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The section of neutral that might be overloaded is from the panel downstream to lights and receptacles. This part is not (must not) be bonded to ground at both ends, only at the end down in the first panel in from the meter.

Also do not connect two generators in parallel! If they drift out of sync then they will dead short each other, possibly destroying both and possibly starting a fire.
 
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Old 04-19-20, 06:23 AM
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When you have a share neutral circuit in your panel the two hot lines are connected to opposite legs in the panel. This causes the neutral to only the difference in current between the hots.
If both hots are on the same leg, like when your generator has the two hots tied together, the neutral sees the sum of the current. So if the two hot were both drawing the maximum of 15 amps the neutral would be seeing 30 amps.
 
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Old 04-21-20, 01:58 AM
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I'm still not understanding how it would overload the neutral. I think it's because the service panel is rated at 200a and the cord coming from the generators are 10 awg, which is rated for 30 amp service.

What am I missing?
 
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Old 04-22-20, 08:26 AM
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I hope you understand that 2 compatible 120v generators in parallel are just driving the same phase 120v output, just with 2 motors instead of one. They cannot be connected to a system out of phase to get 240v. If you want to do this properly, get a 240v generator with a transfer switch or an interlock. Otherwise just stick to extension cords - the correct way to use a low powered 120v generator.

If inverter power is your goal for your main circuits, google 240v inverter generators for may choices, Please connect your choice properly in accordance with code.
 
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Old 04-22-20, 09:05 AM
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I am sorry but I cannot understand why you want to open a can of worms when you have a unit that does the job.

Why not figure out how to set it up so that using it is not such a hassle?
 
 

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