Generator Power Inlet sharing with a panel.

[imjustdave]

Hello everyone.

So I am trying to solve multiple issues in a simplified manner. I have a semi portable generator that I need to hook up to the home and have been looking at the following
http://www.reliancecontrols.com/ProductDetail.aspx?PB50
But at the same location that I would install this I need 120Volt plug, 220V plug for an air compressor and would like to have a 50 Amp, and 30 Amp travel trailer
Yeah I know lots of plugs and all currently outside.

So I started thinking and think this would be a great solution

Install this panel.
http://www.homedepot.com/p/Eaton-Power-Outlet-Panel-Unmetered-CHU1N7N4NS/100168377
this would take care of 115v, and the 2 trailer plugs.

Then I could install a 2 pole 20 amp breaker with a flex line coming out of the bottom going to the Air compressor which will be about 5 feet away.
And lastly I could install
http://www.reliancecontrols.com/ProductDetail.aspx?PK50 in the bottom, as in the plug would be vertical going in.

thoughts?
I see enough breaker slots for all of this
I see enough plugs.
My compressor line would be hardwired with the breaker right there.
Generator input line should fit inside with no issue.
1 box on the outside of my home VS multiple holes and boxes.

Q I have
From my main panel I would have neutral and grounds to the panel could I tie into those for the generator input? This would save me 2 runs back to the main panel and a lot less wire inside the sub.

Ok ... let me have it.

 

[wyliesdiesels]

One big issue- how do u plan on isolating the generator feed from the PoCo feed? And just "turning of the main" isnt acceptable. U need either an interlock or a transfer switch!

 

[imjustdave]

One big issue- how do u plan on isolating the generator feed from the PoCo feed? And just "turning of the main" isnt acceptable. U need either an interlock or a transfer switch!

Sorry that issue is already taken care of "interlock" which is why I left it out but I should have mentioned it. So back to my question.

 

[fastjohnny]

I put my inlet in the bottom of my external main panel (with use of an interlock)as you indicate your design would be. It is in a covered breezeway, and is plenty weatherproof by default, being installed upside down, IMHO.

With regard to how you are running power to the plugs, as I see it, if you are using the plugs when not on gen power, and your interconnect is properly wired, you need to be powering your box from the main panel, with gen feed going through the inlet, back to main panel. Maybe share a ground, but don't think you can share the neutral.

Disclaimer: Not an electrician, but I haven't burned anything down with my wiring.

 

[theoldwizard1]

Your generator feed needs to run directly from the external male inlet to the main panel and connect to the breaker that is mechanically interlocked with the main breaker.

Anything after that is just "normal" wiring. This is the primary benefit of an interlock.

The generator must be un-bonded. The generator ground and neutral should be connected to the appropriate bus bars in the main panel.

If you want the generator to power something else (compressor or RV) that NEVER receives power from the main panel, then there should be no neutral or ground connects of the box to the main panel. (i.e. keep this 100% disconnected form the rest of your wiring).

 

[Charles (in GA)]

The generator inlet would have to be wired completely, all four wires, back to your main panel,and tie in there, from there, your main panel can distribute power back to the subpanel. It is OK to use the subpanel for a box to attach the inlet connector, but you cannot share the neutral back to the main panel and probably should not share the ground either.

The connector you show is not a standard 30 amp generator inlet connector. Not sure what you need for your situation however.

You would have to move one of the single pole breakers from the right to the bottom left to make room for the double pole for the compressor.

 

[imjustdave]

The generator inlet would have to be wired completely, all four wires, back to your main panel,and tie in there, from there, your main panel can distribute power back to the subpanel. It is OK to use the subpanel for a box to attach the inlet connector, but you cannot share the neutral back to the main panel and probably should not share the ground either.

The connector you show is not a standard 30 amp generator inlet connector. Not sure what you need for your situation however.

You would have to move one of the single pole breakers from the right to the bottom left to make room for the double pole for the compressor.

Can you explain why I could not use the neutral and ground that are already going to the sub. The sub panel and generator are both Un bonded. The sub will have 125 amp worth of ground and neutral from the main. Generator can only provide 50 amps worth of power. The interlock on the gen breaker in the main panel will take care of L1 and L2 from the generator.
Is it a flow direction issue load vs source? Say I run the compressor while on generator + lights in the home.

David

 

[ishiboo]

Lot of arguing to try and save a few bucks.

Install the generator inlet completely separate from your sub. 2-2-2-4 SER (Al) might be the cheapest and has plenty of room over 50A.

 

[pattenp]

So you're saying you want to run the gen's 2 hots back to the main panel to the interlocked breaker, but connect the gen's neutral and ground at the sub-panel? Technically that will work. I'm just trying to think if that creates a code issue.

 

[imjustdave]

Lot of arguing to try and save a few bucks.

Install the generator inlet completely separate from your sub. 2-2-2-4 SER (Al) might be the cheapest and has plenty of room over 50A.

ishiboo

Not trying to argue at all just trying to be smart. In my daily job I get paid to save money, think outside the box ETC. Where my generator is located I have a bunch of empty space so my thoughts are to have my compressor there, 110V power for a battery tender on the generator battery, its also next to where I park the camper, don't need a 50 and 30 amp at the same time for the trailer but why not if im already doing all the work... I original plan was to go back to the main panel as its not that far, but a sub panel frees up space and does simplify a few things and gives it a nice clean look VS box box, cover, Plug outlet, Plug, disconnect. ... Guess maybe sharing the G and N was a little much to ask in my quest...

I love the ideas everyone but I want to be within code and safe.

 

[imjustdave]

So you're saying you want to run the gen's 2 hots back to the main panel to the interlocked breaker, but connect the gen's neutral and ground at the sub-panel? Technically that will work. I'm just trying to think if that creates a code issue.

Correct as the sub panel will have much larger Neutral and ground already run. Wondering if I would have an issue with the direction of power flow if I do this. Supply VS load. While on Generator power, any loads from that panel and the main panel could have the path trying to running in 2 directions. That could be an issue so I'm asking the Q.

Thank you to everyone who has help out as well.

 

[theoldwizard1]

So you're saying you want to run the gen's 2 hots back to the main panel to the interlocked breaker, but connect the gen's neutral and ground at the sub-panel? Technically that will work. I'm just trying to think if that creates a code issue.

More importantly, would the inspector pass it ?

General rule of thumb, it looks different/odd, it gets a red flag.

 

[dlcwent]

Great info. Thanks

 

[fastjohnny]

If you did not flip your transfer switch/interlock prior to starting your generator, what would happen to the neutral, having potential for current from 2 sources, gen and po co?

240 shares neutral due to phase, but what happens when you have 120, and 120 from Gen, and the same from po co, and you try to use your compressor or RV with the same neutral?

Just trying to wrap my mind around it.

I'd go with above suggested of running 2-2-2-4 from inlet to main panel, that would get you plenty capacity to upgrade generator should you go that route.

 

[imjustdave]

Neutral and the ground don't get switched anyways. But the hots have a interlock preventing both from being on at the same time