The historic use case for a pedestal is to supply electricity to a single unit. As my example indicated, I can see a growing need to plug two things into a campground pedestal; vehicle and trailer. As you indicated, that would cause a breaker in the Campground Service panel to trip if more than 50A was needed on a leg.
First, full disclosure. I have no idea how EV's are charged so what I am proposing may be feasible in theory only.
What I’m thinking that needs to be developed is a custom 50A dog bone adapter with one input and two outputs. The input would be a standard 50A NEMA 14-50P plug. The first output would be fed from one 50A leg of the pedestal terminating in either a 30A or 50A RV receptacle, where the 50A receptacle would feed both legs of the RV, much like a 30A to 50A dog bone. The second output would be fed from the other 50A pedestal leg and terminate in a receptacle that could be used to charge an EV.
Campground power grids aren’t designed for EV charging since the NEC only use 9,600 watts per pedestal for load calculations. Any individual EV charging stations at campsites will probably require a secondary grid installed. Campgrounds are not happy with charging an EV while an RV is being powered.
Great article. I have a question about the breaker wiring in the Campground Service Panel.
Given how you have diagrammed the wiring in the Pedestal, it is possible to draw 80A from one of the legs going back to the Service Panel. Are Service Panels wired to account for this potential draw? Or is it assumed one would use either 30A or 50A but not both?
A simple example. Let’s say a person is towing a 30A trailer with a Tesla on a hot day. They plug the trailer into the 30A receptacle, turn on the air and hot water heater, drawing 28A. Then they plug the Tesla into the 50A receptacle to charge it up for the next day, drawing the full 100A (50A from each leg).
The service panel should have a circuit breaker sized to protect the conductors. So if it’s fed by a 2-pole 50-amp breaker, then once you exceed 50-amps on either leg of the pedestal it will soon trip. Pedestals are not required to provide 50+50+30+20 amps of current. It’s kind of a name game…
Question: Have EMS for 30 Amp 2014 Itasca Sunstar. While plugged into pedestal, breaker flipped off. Was cg tech correct claiming perfect storm ? Ran gen during 2 hr drive in 90 degree temp to run coach ac and frig. Soon after plugged into 30 amp recepticle with ac, frig, water heater, br fan on electric, breaker went off. Water heater and 1 ac pulled about 28 amps. Tech said breaker went off due to draw over 30 amps and converter trying to recharge batteries. Switched to gas water heat abd no problem. Thanks
I’ll do a full article on this later. Remember that your Air Conditioner compressor can easily pull 50 amps of inrush current on startup, so your 28-amp measurement is while the air conditioner is running.
When connected to 30-amp shore power you generally need to run your water heater on propane, not electric. Do you have a Soft Start unit installed on your air conditioner? Here’s how they work.
Great article Mike! Thanks for put all of this in one place. Will a good surge protector detect the error you mentioned where the campground mis-wired the hots of a 50 A receptacle with a single hot leg where the hot pole to hot pole voltage is zero? Do a surge protector know or care if 3-phase power is being used and there is 208 V pole to pole?
I don’t know of any brand Surge Protector that will detect a single-leg 50-amp receptacle. However, SurgeGuard monitors the neutral current and will shut down power if it reaches some threshold, 70 amps I think…
Also, Surge Protectors don’t monitor for WYE 3-phase 208-volts. But an advanced EMS will detect and shut down a High-Leg Delta connection miswired with 208 Volts.
Would it be accurate to say, then, before plugging in, to use a meter on the two hot legs to ensure 208-240v, and then the Power Watchdog (in my case) would confirm everything else is OK?
The historic use case for a pedestal is to supply electricity to a single unit. As my example indicated, I can see a growing need to plug two things into a campground pedestal; vehicle and trailer. As you indicated, that would cause a breaker in the Campground Service panel to trip if more than 50A was needed on a leg.
First, full disclosure. I have no idea how EV's are charged so what I am proposing may be feasible in theory only.
What I’m thinking that needs to be developed is a custom 50A dog bone adapter with one input and two outputs. The input would be a standard 50A NEMA 14-50P plug. The first output would be fed from one 50A leg of the pedestal terminating in either a 30A or 50A RV receptacle, where the 50A receptacle would feed both legs of the RV, much like a 30A to 50A dog bone. The second output would be fed from the other 50A pedestal leg and terminate in a receptacle that could be used to charge an EV.
Campground power grids aren’t designed for EV charging since the NEC only use 9,600 watts per pedestal for load calculations. Any individual EV charging stations at campsites will probably require a secondary grid installed. Campgrounds are not happy with charging an EV while an RV is being powered.
Mike,
Great article. I have a question about the breaker wiring in the Campground Service Panel.
Given how you have diagrammed the wiring in the Pedestal, it is possible to draw 80A from one of the legs going back to the Service Panel. Are Service Panels wired to account for this potential draw? Or is it assumed one would use either 30A or 50A but not both?
A simple example. Let’s say a person is towing a 30A trailer with a Tesla on a hot day. They plug the trailer into the 30A receptacle, turn on the air and hot water heater, drawing 28A. Then they plug the Tesla into the 50A receptacle to charge it up for the next day, drawing the full 100A (50A from each leg).
The service panel should have a circuit breaker sized to protect the conductors. So if it’s fed by a 2-pole 50-amp breaker, then once you exceed 50-amps on either leg of the pedestal it will soon trip. Pedestals are not required to provide 50+50+30+20 amps of current. It’s kind of a name game…
https://rvelectricity.substack.com/p/is-there-such-a-thing-as-a-100-amp
Question: Have EMS for 30 Amp 2014 Itasca Sunstar. While plugged into pedestal, breaker flipped off. Was cg tech correct claiming perfect storm ? Ran gen during 2 hr drive in 90 degree temp to run coach ac and frig. Soon after plugged into 30 amp recepticle with ac, frig, water heater, br fan on electric, breaker went off. Water heater and 1 ac pulled about 28 amps. Tech said breaker went off due to draw over 30 amps and converter trying to recharge batteries. Switched to gas water heat abd no problem. Thanks
I’ll do a full article on this later. Remember that your Air Conditioner compressor can easily pull 50 amps of inrush current on startup, so your 28-amp measurement is while the air conditioner is running.
When connected to 30-amp shore power you generally need to run your water heater on propane, not electric. Do you have a Soft Start unit installed on your air conditioner? Here’s how they work.
https://rvelectricity.substack.com/p/the-rise-of-hrdl-high-rate-data-logger
Thanks for putting these together. I learn something new every one of these I read. Just wanted you to know you are appreciated!
Great article Mike! Thanks for put all of this in one place. Will a good surge protector detect the error you mentioned where the campground mis-wired the hots of a 50 A receptacle with a single hot leg where the hot pole to hot pole voltage is zero? Do a surge protector know or care if 3-phase power is being used and there is 208 V pole to pole?
I don’t know of any brand Surge Protector that will detect a single-leg 50-amp receptacle. However, SurgeGuard monitors the neutral current and will shut down power if it reaches some threshold, 70 amps I think…
Also, Surge Protectors don’t monitor for WYE 3-phase 208-volts. But an advanced EMS will detect and shut down a High-Leg Delta connection miswired with 208 Volts.
Would it be accurate to say, then, before plugging in, to use a meter on the two hot legs to ensure 208-240v, and then the Power Watchdog (in my case) would confirm everything else is OK?
Yes, that’s the safest way if you’re in an iffy power situation.