Newbie electrical question

[PB2]

Our rig is a 30a coach. I understand i can safely plug into a 50a plug with the proper adapter/dog bone. My question is how often do you encounter campsites with only 50a service? I don't have the dog bone and wonder how often i would need one...


Thanks!

[Craig1960]

It's always the other way for me I find. No 50amp just 30amp.

[The Brews Cruise]

As a retired electrician, I wouldn't call connecting a 30 amp coach to a 50 amp circuit "safe". It can be done with a "dogbone" adapter. The problem I see is that your cord and internal wiring to your panel is sized for 30 amps, but the 50 amp overcurrent protection will not protect the wiring for overload. An overload condition could possibly allow 40 to 50 amps to flow on the smaller size wiring, causing it to overheat. If you had a way to have 30 amp protection connected to the 50 amp at the power post, then your wiring would be properly protected.
I'm sure that many people carry the adapters to connect their 30 amp coach to the 50 amp circuit, and they have had no problems...yet. You're going to get conflicting advice on this, and I'm sure there are plenty that disagree with me. With 47 years active in the electrical trade prior to retirement I've seen enough to know that it's not something I would do.

[Epp]

It only takes one time and you will need it. LOL.
On our last trip we stayed on site at a car show being held at an older airport. Where I had to park the rig my 50 amp cord would not reach the power box. So I used a 50 to 30 adapter and ran my 30 amp cord over to the power box only to discover the power box only had a 50 amp and 20 amp connection. I carry every adapter known to mankind except for 30 to 50. I have one of these now. So yes some places do only have 50 amp outlets, the adapters really don’t take up that much space for the convenience of not having to run out to the store to pick up an adapter when you’re setting up camp.

The post above brings up a good point about whether or not you have a 30 amp breaker installed in your rv breaker box to prevent an overload. This was not a factor in the example I gave for my particular situation.

Epp

[hamm2018]

Originally Posted by PB2

Our rig is a 30a coach. I understand i can safely plug into a 50a plug with the proper adapter/dog bone. My question is how often do you encounter campsites with only 50a service? I don't have the dog bone and wonder how often i would need one...


Thanks!

We are going to a Famcamp in Mayport, Osprey Cove, it only has 50 amp.
But when we run into a situation like you are asking, it is only 30 amp, 50 amp not available. Some times we run across this in some Thousand Trails parks.
Carry a dog bone with you so you will be prepared.

[CLIFFTALL]

This will depend on how often you camp and where. It only takes one time to realize it’s a good investment. I wouldn’t leave home without it when I had a 30 amp RV and conversely a 50 to 30 when I had a 50 amp RV.

Originally Posted by PB2

Our rig is a 30a coach. I understand i can safely plug into a 50a plug with the proper adapter/dog bone. My question is how often do you encounter campsites with only 50a service? I don't have the dog bone and wonder how often i would need one...


Thanks!

[PB2]

Originally Posted by The Brews Cruise

As a retired electrician, I wouldn't call connecting a 30 amp coach to a 50 amp circuit "safe". It can be done with a "dogbone" adapter. The problem I see is that your cord and internal wiring to your panel is sized for 30 amps, but the 50 amp overcurrent protection will not protect the wiring for overload. An overload condition could possibly allow 40 to 50 amps to flow on the smaller size wiring, causing it to overheat. If you had a way to have 30 amp protection connected to the 50 amp at the power post, then your wiring would be properly protected.
I'm sure that many people carry the adapters to connect their 30 amp coach to the 50 amp circuit, and they have had no problems...yet. You're going to get conflicting advice on this, and I'm sure there are plenty that disagree with me. With 47 years active in the electrical trade prior to retirement I've seen enough to know that it's not something I would do.

Really good advice - thanks! I have a 30a surge protector with EMS. Does that offer me some level of protection if i plug into 50a service?


Thanks all for the comments. I think having one in the kit will be a good idea.

[mrboyer]

Originally Posted by PB2

Really good advice - thanks! I have a 30a surge protector with EMS. Does that offer me some level of protection if i plug into 50a service?


Thanks all for the comments. I think having one in the kit will be a good idea.

Not knowing which EMS you have, I suggest that you check the specifications to see if it has over current protection. I doubt that it does. One could make their own 50 to 30 adapter with a 30 amp breaker in the line. If you dont know how, please don’t try it.

[bigchick]

Originally Posted by PB2

Really good advice - thanks! I have a 30a surge protector with EMS. Does that offer me some level of protection if i plug into 50a service?


Thanks all for the comments. I think having one in the kit will be a good idea.

the EMS will provide over / under voltage protection. it will not provide overload protection. that is the job of the circuit breakers on the pedestal and the main breaker in you distribution panel.

[twinboat]

Originally Posted by The Brews Cruise

As a retired electrician, I wouldn't call connecting a 30 amp coach to a 50 amp circuit "safe". It can be done with a "dogbone" adapter. The problem I see is that your cord and internal wiring to your panel is sized for 30 amps, but the 50 amp overcurrent protection will not protect the wiring for overload. An overload condition could possibly allow 40 to 50 amps to flow on the smaller size wiring, causing it to overheat. If you had a way to have 30 amp protection connected to the 50 amp at the power post, then your wiring would be properly protected.
I'm sure that many people carry the adapters to connect their 30 amp coach to the 50 amp circuit, and they have had no problems...yet. You're going to get conflicting advice on this, and I'm sure there are plenty that disagree with me. With 47 years active in the electrical trade prior to retirement I've seen enough to know that it's not something I would do.

You are only carrying a 50 amp potential thru the power cord, ATS, and short wire to the 30 amp main breaker.
Any overload beyond that will trip the 30 amp main breaker.

I mentioned 50 amp potential because you will probably need a dead short to draw over 30 amps.

Its no different then plugging a lamp, with 16 gauge wire, into a 20 amp outlet. You just can't put a big enough bulb in to trip the breaker.
Cut the cord and connect the wires together and it will probably trip the breaker.

[MSHappyCampers]

I've never seen a campground with 50A service that didn't also have a 30A outlet on the same post.

The dogbones aren't expensive, so I would have one, just in case!

[Wrapped]

Get the dog bone, 30 amp rig pulled in next to us an the park pedestal had the normal 50 30 20 amp plugs but the 30 amp receptacle was broken and unusable, they called, campground maintenance, they showed up checked it out and gave them a 50 to 30 amp dog bone to use until it could be fixed.

[Ldubs]

Originally Posted by The Brews Cruise

As a retired electrician, I wouldn't call connecting a 30 amp coach to a 50 amp circuit "safe". It can be done with a "dogbone" adapter. The problem I see is that your cord and internal wiring to your panel is sized for 30 amps, but the 50 amp overcurrent protection will not protect the wiring for overload. An overload condition could possibly allow 40 to 50 amps to flow on the smaller size wiring, causing it to overheat. If you had a way to have 30 amp protection connected to the 50 amp at the power post, then your wiring would be properly protected.
I'm sure that many people carry the adapters to connect their 30 amp coach to the 50 amp circuit, and they have had no problems...yet. You're going to get conflicting advice on this, and I'm sure there are plenty that disagree with me. With 47 years active in the electrical trade prior to retirement I've seen enough to know that it's not something I would do.

Good stuff, thanks for sharing. I am wrong to assume that if I used my 30 AMP power/surge guard I would be protected? EDIT: Sorry, I see this was already addressed. Thanks.

[Podivin]

Originally Posted by The Brews Cruise

As a retired electrician, I wouldn't call connecting a 30 amp coach to a 50 amp circuit "safe". It can be done with a "dogbone" adapter. The problem I see is that your cord and internal wiring to your panel is sized for 30 amps, but the 50 amp overcurrent protection will not protect the wiring for overload. An overload condition could possibly allow 40 to 50 amps to flow on the smaller size wiring, causing it to overheat. If you had a way to have 30 amp protection connected to the 50 amp at the power post, then your wiring would be properly protected.
I'm sure that many people carry the adapters to connect their 30 amp coach to the 50 amp circuit, and they have had no problems...yet. You're going to get conflicting advice on this, and I'm sure there are plenty that disagree with me. With 47 years active in the electrical trade prior to retirement I've seen enough to know that it's not something I would do.

Seems to me that's what the 30 amp main breaker in the RV is for. The RV isn't going to pull more than 30 amps, if it tries to it will trip the main.