Location and sizing of Generator Plug

[GDN]

I'm ready to embark getting set up to use the truck for power backup to the house. With no good option for a whole panel neutral switch I'm going with the panel lockout and a generator plug. Two questions I'm looking for some feedback / insight on. A note - my electrical panel is on the wall of the garage I park on, right near the front tire.

1 - Location of generator plug. I would really like this on the inside wall of the garage I park on. I'd only need a short cable depending on where it is located and I can plug in and remain out of the weather. My electrician says by code it has to go outside. I understand likely that is due to dangers of a gas generator indoors/in the garage. Is there some other code that would allow it to go in the garage? I've seen a number of pictures from installs with it inside. Are those homeowner installs or to code?

2 - Size of generator plug. I know from the truck I'm only going to get 30 amps. However I like to future proof when I can - I'd like to have a 50 amp generator plug connected to the panel. For my connector cable can I have the 30 amp plug for the truck, but the 50 amp on the other end to plug in to the generator plug? Or is this overkill?

Thanks for the feedback.

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[MapleMan650]

I did a 50 amp inlet because I also have a portable generator capable of 50 amps. With more and more things becoming electrified, I wanted to do a little future proofing while I was at it. I have a 50 amp generator cord with a 30 amp adapter for the truck. It works great. https://a.co/d/9Ui4tdu

**Edit, no answer for you on your first question. I have a detached garage on a sub-panel so I had to install my inlet on the side of my house.

 

[Bandit216]

In reverse order of what you asked:

The only circuits greater than 30Amps that most typical houses might have are Air Conditioner, electric clothes dryer, electric range, and electric baseboard heaters. If you have gas dryer, gas range, and\or a gas furnace, there is no need for a 50A generator or 50A plug. Under most cases, for an average size house, the ~7kw surge capability of a 30A generator will take care of most household circuits.

How I dealt with the option of having both a 30A 240v generator and the 30A Lightning Pro Power:

My dual fuel generator sits outside on my deck next to the male 30A generator input plug. (Carbon Monoxide problem solved.) For the Lightning pro power option, I installed a permanent 30A extension circuit with one 30A male plug end in the garage and a 30A female plug end on the deck next to the 30A generator input plug described above.

For my secondary backup power primary option I keep a short 30A generator cable connected between the two deck outlets. (I keep the short cable connected all the time so I don't have to go out in the dark and in the cold to connect it up). If the power goes out and my primary backup power option (a stand alone Lithium battery for the solar array) runs low, I go to the garage, start the Lightning, enable the power outlet in the bed and connect another 30A cable between the 30A Pro Power outlet and the male generator input plug on the interior garage wall next to the Lightning. (The cost of installing the generator extension circuit between the garage and the deck was only about $250 - self installed but with a licensed electrician inspection)

Then, only if the Lightning starts to run out of juice do I go to my third backup power option - the fuel generator on the deck. Then, I, 1)unplug the short cable connecting the 30A output circuit from the garage to the 30A generator input outlet on the deck, 2) connect the 30A output of the generator to the generator input outlet formerly used by the Lightning, 3)start the generator and turn on its output circuit 4) turn off pro power outlets in the bed and disconnect the cable between the Lightning output and the garage wall input outlet. If needed, I can then drive the Lightning to a working DC fast charger. charge it up, then return home and replace the noisy generator on the deck with the newly recharged Lightning.

Obviously, my backup power setup is different in that my generator input doesn't directly power the critical circuit panel. The 30A generator input power provided on the deck (from the Pro power outlet or the fuel generator) charges the stand alone Lithium battery for the critical circuit panel if the power goes out. The generator transfer switch, DC\AC inverter, and the power transfer logic circuits built into the solar inverter safely handle the power transfer and conversion.) The simple extension cord method from Pro Power won't work for my two most important circuits - my boiler heat and my well pump.

My backup power redundancy may seem complex and expensive but the house once experienced $20,000 of water damage from a mid-winter, extended power outage when no one was home - multiple backup power options lesson learned the hard way.

By using a manual breaker interlock your whole house single-panel approach will be simpler, but it sounds like a stand-alone extension circuit from inside your garage to your outside generator location might work for you, as well. You will want to turn off any circuit breakers greater than 30A to prevent inadvertent powering of those higher demand 240v circuits.

 

[MapleMan650]

The only circuits greater than 30Amps that most typical houses might have are Air Conditioner, electric clothes dryer, electric range, and electric baseboard heaters. If you have gas dryer, gas range, and\or a gas furnace, there is no need for a 50A generator or 50A plug. Under most cases, for an average size house, the ~7kw surge capability of a 30A generator will take care of most household circuits.

Our house heat runs on a mini-split system. It’s only a few years old and very efficient but a 30A generator isn’t enough. To be able to run that, plus the fridge and sump pumps, we needed a 50A. Most of the time, we just put on some extra sweatshirts and use the truck for everything else but sometimes it’s nice to kick on the 50A generator and have some real heat.

 

[Maquis]

The requirement in 702.12(B) to locate the generator inlet outdoors was a recent addition to the code (2023 edition, I believe).
I wouldn’t hesitate to put it in the garage if my area hasn’t yet adopted the code that requires it.

 

[tls]

Our house heat runs on a mini-split system. It’s only a few years old and very efficient but a 30A generator isn’t enough. To be able to run that, plus the fridge and sump pumps, we needed a 50A. Most of the time, we just put on some extra sweatshirts and use the truck for everything else but sometimes it’s nice to kick on the 50A generator and have some real heat.

Did you test it? I have a 48,000 BTU mini split that runs full-bore in the depths of winter (we occasionally do get close to its -14F minimum rating) and though it's on a 30A circuit, like most HVAC equipment that's just to handle the startup surge when it cycles. The same is true for a sump pump and for a fridge. You'd have to have very bad luck for them to all start their motors at the same instant...and then you could just turn one of them off manually (so they don't all try to start at once when the power comes back on) and reset the breaker, then turn everything back on. Or so it would seem to me, anyway.

 

[luebri]

By using a manual breaker interlock your whole house single-panel approach will be simpler, but it sounds like a stand-alone extension circuit from inside your garage to your outside generator location might work for you, as well. You will want to turn off any circuit breakers greater than 30A to prevent inadvertent powering of those higher demand 240v circuits.

If using a full panel manual breaker interlock how are you getting around the Bonded Neutral fault error on the truck?

 

[MapleMan650]

Did you test it? I have a 48,000 BTU mini split that runs full-bore in the depths of winter (we occasionally do get close to its -14F minimum rating) and though it's on a 30A circuit, like most HVAC equipment that's just to handle the startup surge when it cycles. The same is true for a sump pump and for a fridge. You'd have to have very bad luck for them to all start their motors at the same instant...and then you could just turn one of them off manually (so they don't all try to start at once when the power comes back on) and reset the breaker, then turn everything back on. Or so it would seem to me, anyway.

I did. Ours is only a 42k BTU but it requires a 40A circuit. I thought I would give it a shot anyway since it’s an inverter style motor and the LRA is 28.8 but no dice. We get airflow but no real heat. When I hook it up to my big portable generator, it works just fine.

 

[mefly2]

If using a full panel manual breaker interlock how are you getting around the Bonded Neutral fault error on the truck?

My question as well ...

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