50 amp 12000 watt generator plug

sparkync

Senior Member
Location
North Carolina
I have a customer who has a 12000 watt portable generator with a 50 amp straight plug receptacle. First question, Obviously the receptacle does not have to be a twist lock?. This is the outlet that I'm figuring the cord will plug into, to plug into a 3 or 4 wire generator box with twist lock receptacle in it. . 2nd question: I'm assuming that the box it plugs into only has to be 3 wire since I don't seem to be able to find a 4 wire box. Is this standard on 50 amp generators? I'm assuming this kind of generator has a "floating neutral" and doesn't need a neutral??
Thanks for any input.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
If, by "box" you mean inlet, there are plenty of 4-wire ones, but I would probably hard-wire the house end of the cord.
 

Todd0x1

Senior Member
Location
CA
A number of manufacturers make 14-50P to CS6364 cords for this purpose. The inlet box is 4 wire with a CS6375 male inlet. At first glance these 50 amp 4 wire twistlocks can look like a 3 wire connector because they only have 3 blades, the EGC is a contact on the side of the connector's shell.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I have a customer who has a 12000 watt portable generator with a 50 amp straight plug receptacle. First question, Obviously the receptacle does not have to be a twist lock?. This is the outlet that I'm figuring the cord will plug into, to plug into a 3 or 4 wire generator box with twist lock receptacle in it. . 2nd question: I'm assuming that the box it plugs into only has to be 3 wire since I don't seem to be able to find a 4 wire box. Is this standard on 50 amp generators? I'm assuming this kind of generator has a "floating neutral" and doesn't need a neutral??
Thanks for any input.
The generator needs a 4 wire receptacle for this to work. Does it have 4 conductors?
 

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
Hopefully the receptacle on the generator looks like a 50A electric range outlet (4 wire version). They don't have to be twist lock. That's what mine has, and I used the CS6364 to 14-50P cord to connect it to the house.
 

sparkync

Senior Member
Location
North Carolina
Ok, I guess I just didn't see the ground clip on the ones I was looking at. I just saw the 3 prongs and was expecting 4 prongs. I see it has a 4th clip on the side that I'm assuming is the ground
 

sparkync

Senior Member
Location
North Carolina
The feed for this generator will be coming from the "main" electrical panel, not a subpanel. The ground and neutral are bonded together in the main panel, therefore looks like the wiring could be 3 wire to the inlet box and the neutral from the generator bonded to the ground in the inlet box. Am I correct? If I run a 4 wire to the inlet box, they will still be tied together in the "main panel".
 

sparkync

Senior Member
Location
North Carolina
Obviously if the 3 prong 50 amp with the ground on the side is used, a special type of male connector will be needed, I'm guessing a "marine type"?
If anyone can find a 4 wire 50 amp twist lock type with female receptacle in it, please forward it to me. I did see a "Midwest brand" and "GE brand" (not good rating on this one though), but that's about all in 50 amp 4 prong. Thanks again.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
The feed for this generator will be coming from the "main" electrical panel, not a subpanel. The ground and neutral are bonded together in the main panel, therefore looks like the wiring could be 3 wire to the inlet box and the neutral from the generator bonded to the ground in the inlet box. Am I correct? If I run a 4 wire to the inlet box, they will still be tied together in the "main panel".
That is not correct, you have to run a grounded conductor and an EGC (grounding). You're also saying it backwards, you are not feeding the generator, the generator would be feeding the panel during a power outage.
 

Todd0x1

Senior Member
Location
CA
Obviously if the 3 prong 50 amp with the ground on the side is used, a special type of male connector will be needed, I'm guessing a "marine type"?
If anyone can find a 4 wire 50 amp twist lock type with female receptacle in it, please forward it to me. I did see a "Midwest brand" and "GE brand" (not good rating on this one though), but that's about all in 50 amp 4 prong. Thanks again.

I gave you the part number for the male inlet, CS6375. A number of manufacturers make boxes with them. A popular one is Reliance. These are in somewhat short supply at the moment from everyone installing generator hookups after what happened in texas (and everywhere else...)
 

sparkync

Senior Member
Location
North Carolina
I'm sorry. The number CS6375 comes up to a 3 prong inlet box. I understand that the ground clip is on the side. Does this take a "marine" type plug? I'm use to the 4 prong twist locks but not this type. Also the generator "owner's manual calls for a ground rod. The generator is "portable", and will not be in a stationary place all the time. The house "ground" is already connected to 2 ground rods at the service therefore the generator will be grounded through the "electrical grounding" conducter, right?
Thanks
 

Todd0x1

Senior Member
Location
CA
I'm sorry. The number CS6375 comes up to a 3 prong inlet box. I understand that the ground clip is on the side. Does this take a "marine" type plug? I'm use to the 4 prong twist locks but not this type. Also the generator "owner's manual calls for a ground rod. The generator is "portable", and will not be in a stationary place all the time. The house "ground" is already connected to 2 ground rods at the service therefore the generator will be grounded through the "electrical grounding" conducter, right?
Thanks

The CS6375 is part of the 125/250V 3 pole 4 wire (Hot-Hot-Neutral-Ground) group of CS series 50 amp twistlock connectors. The part numbers relative to your project are CS6364 which is the female cord end, and CS6375 which is the inlet. These are 4 wire devices. These are the ones to use.
 

Todd0x1

Senior Member
Location
CA
Here, I took some pictures for you of the inlet CS6375, and mating connector CS6364. You have to use the part numbers for these things not description like "marine plug", and not just by using a picture. There are a bunch of different ones of these that look identical but have different ratings and do not mate.

20210410_063715-1200.jpg 20210410_063722-1200.jpg 20210410_063743-1200.jpg 20210410_063749-1200.jpg
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
The CS6375 is part of the 125/250V 3 pole 4 wire (Hot-Hot-Neutral-Ground) group of CS series 50 amp twistlock connectors. The part numbers relative to your project are CS6364 which is the female cord end, and CS6375 which is the inlet. These are 4 wire devices. These are the ones to use.
I have a 50 amp inlet for my generator. I used a Connecticut Electric 50a inlet for it's larger wiring compartment. Some of the other brands are ridiculously small when trying to splice in the #8 or #6 conductors.
50 Amp Gen Inlet.jpg

 
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