I'm (finally) getting around to installing a transfer switch for my portable generator. The purpose of my post here is to check for any NEC violations, or safety issues, whatever. I've had the switch over two years so I think it's time I installed it. I'll pass my final decisions past my local code enforcement officer so it'll all be done to code, and will be inspected. From my initial contact, he wants to see a schematic representation of the installation in a line drawing. No problem there.
Country: US. Very rural area, lose power often.
I have a 5,000W generator with an L5-30 120/30A receptacle and an L14-20 120/240V 20A receptacle. I plan to use the 120/240 so I can run the well pump, 1 HP, 240V submersible, so I need the split phase output. There are no other 240V appliances other than the dryer, which I'm not worried about running. It'll be about the only thing can run when it's needed, but that's OK; one or two lights after the pump gets started and I should be fine current-wise. I'm not worried about managing capacity. The generator DOES have breakers, and it's an industrial grade generator for what it's worth. The Transfer Switch, a 7,500 watt device, has a 125/250V 30A plug on it to connect to it. I'm not planning to use an outdoor Power Inlet Box, simply because 1. There is a disconnect at the generator itself, and the generator will be located right beside the power meter when it's used, under an overhang, but completely outdoors and highly visible. 2. It costs money and only about 7-8 ft of cord are required anyway.
Here are my questions: -- Can I avoid use of the outdoor Power Input box and still satisfy the requirement for a manual disconnect? As I said, the cord is simply plugged and unplugged from the generator itself. Inside of course, the cord can be pulled from the transfer switch also. The transfer switch is mounted right next to the mains breaker box. Reading the requirements it's confusing; they say a manual disconnect is necessary, and the box is an option item, but ... why? I could see if it were direct-wired to the generator, but it's not. I can't find an allowance for the generator manual disconnect, in other words.
-- I'll have to use a 20A 4-wire cord with the L14-20 plug on one end for the generator, and a 125/25-V 30A receptacle on the other end to connect to the transfer switch. Any problems with using 20A wiring on a 30A receptacle? Can't see why there would be.
-- I'm also planning to run the cord into the house through a piece of steel conduit to manage passing thru the wall. Inside, the cord will just run up the wall to the transfer switch and plug in there. The transfer switch is right next to the breaker box. Outside the wall it'll connect to the generator and i'll build a small box to house the cord neatly and out of sight when it's not in use. Might be a good idea to padlock it away from kids etc., hadn't thought of that, but that's why I'm posting my quest, to pick up details like that, too.
All the diagrams I see indicate an outdoor power inlet box outside and a junction box inside. The run for the cord is so short I'm trying to bypass using either of those.
-- And, one last question: If I read things right, I do NOT use the ground strap on the generator to attach to the house ground, right? It's right there and would be easy to use a clamp-on, but from what I read it's not required and in some ways not desirable. It derives its earth from the breaker box in this case, and not the ground rod. Right?
Thanks for any comments or thoughts you may have; I appreciate your taking time to consider my post. I've tried to keep it simple.
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