1974 GMC sequoia motorhome adapter
- Thread starter kwlo7
- Start date
Assuming coach has original 50a plug and that your generator has a regular 15a AC outlet, the best approach is to get a 50a to 30a adapter and a 30a to 15a block. That way you can hook up to 50a, 30a, or 15a supply.
Do you have pictures of what the plug end of the cord looks like.
Or maybe you would need an adapter from 30amp to 50 amp or combination of 20 amp to 30 amp to 50 amp
Many generators have a higher amperage twist lock receptacle in addition to the standard 15 or 20 amp receptacles like those found in your home.
A 30 or 50 amp twist lock is pretty common so one of these adapters should do the trick for you.
30Amp Male Twist Lock to 50Amp Female RV Power Adapter 4Prong -
Shop Nilight 30Amp to 50Amp RV Power Adapter 4Prong Generator Twist Plug L14-30P to 14-50R 30A Male Plug to 50A Female Receptacle for RV Generator Camper Caravan Electrical Power Converter in high quality, support 2 years warranty. 30 Amp 4 prong male plug to 50 Amp female receptacle. Allows you...
www.nilight.com
Valterra Mighty Cord A10-G30450VP Adapter
www.rvpartscountry.com
Be very aware that a 50 amp GMC has 2 separate legs of 120 volts, and is not the same as the 50 amp 240 volts that some larger generators put out. Do your homework before that inexpensive adapter becomes very costly.
Richard,
The GMC Coach (those up-fitted by GMC) with a 50 Amp cord are wired to run from a 50 Amp 240VAC supply. The odd duck is the Onan generator which is wired as a single 120V hot suppling both both "Hots" of the 50 Amp plug.
The issue with a 50 Amp 240VAC shore supply is the possibility of having a poor neutral connection at the pedestal. This is caused by loose female connectors from wear & tear and also oxidation on both the male and female sides from close exposure to weather. A poor neutral connection leads to a imbalance of the voltages between the two Hot feeds and neutral... meaning one circuit could see 50 volts and another see 190 volts.
If campgrounds were wired as single Hot feeds to 50 amp pedestals, I would image they would soon run into load balancing issues between the two phases. The neutral wire in many 50 Amp extension cords is only 8 gauge (the hots being 6 gauge) because the neutral in a 240 VAC system carries only the current difference in the two Hot wires. A number 8 wire is not rated to carry 50 amps but that would happen with one 50 Amp hot feeding both sides. Our coaches OEM cable came with a 6 ga. neutral because the Onan could deliver up to 50 Amps.
Here is a photo of my main AC breaker box. As you can see there are two 40 Amp main breakers (Center white breakers at the top) which are tied together so both Hot sides get disconnected if one main breaker trips, just like in your home. If this was a single Hot system, only a single breaker would be required, like in the Onan. The 3rd party upfitters with 30 Amp cords are single hot fed and limited to 30 amps. The dongles to adapt them to 50 amp services only connect one Hot from the 50 Amp plug through to the 30 Amp socket. The other side is left open.
Okay, thanks for correcting me and the education, Bruce.
You wrote "The GMC Coach (those up-fitted by GMC) with a 50 Amp cord are wired to run from a 50 Amp 240VAC supply." Did other up-fitters not do it that way?
