30 amp vs. 50 amp cord re-visited..

[Bill-N-Donna]

I’ve seen and read discussions on other threads about using the 30 amp cord verses the 50 amp cord. I have in the past been using the 30 amp cord to avoid the nuisance and hassle of the anaconda cord. On our last recent trip during the past couple of weeks, the end of the plug really burnt. Apparently the socket we plugged into was bad not allowing a good enough connection causing it to overheat. As a result the plug on the end of our 30 amp cord and the socket burnt up enough not to be able to use it until it was repaired. All of this happened before it tripped out the breaker.


I was thinking that because I was using the washer/dryer along with the A/C and the electric water heater, I probably was asking for it. However, after the repairs were made a test was done to see what I was pulling and it measured only 22 amps with the washer/dryer, water heater and A/C turned back on. I’m not sure during the test if the water heater was actually pulling anything or not at the time.


This leads me to asking this question; When using a 50 amp cord is the power usage split between two legs on the source rather than pulling everything on one leg as in using a 30 amp, or is it still coming through the same path as it does when hooked up on a 30?

Would the philosophy of “bigger is better” actually hold true in this case or with a bad connection would it still melt down?

On another note, 50 amp service wasn’t available and the 30 amp receptacle was all that was available where I was parked. In this situation would it make any difference on the 30 vs. 50 amp cord?

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[H. John Kohl]

Bill,
It is my understanding that 50 amp has two legs L1 and L2.
When using a 30 amp to 50 amp adapter the 30 amp single leg is jumped to both L1 and L2 on the 50 amp side. So I believe you are correct that 50 amp splits the legs on your circuit breaker panel.

Those with professional knowledge should be along and give you the accurate answer.

[Bill-N-Donna]

Another question, if you’re plugged into a 30 amp service then would it matter one way or the other whether or not you were using the 30 or the 50 amp cord? Doesn’t the 30 amp cord adapt when plugged into the camper? My thinking is that you couldn’t plug in at all without an adapter regardless which ends the adapter is on. I have an adapter that plugs into the camper and one that hangs on the receptacle. Is there any difference in how they work?

[NCFischers]

Bill,
John Kohl is right about the 30 amp adapter feeding both hot legs in the 50 amp power cord. Both adapters work in the same way to supply power to both busses in the circuit breaker panel.
Jim

[camper4]

Bigger is usually better but still no sure thing. A bad connection can cause issues no matter what.

If you only have a 30 amp service at a campground, you can use either the 30 or 50 amp cord. But, you will still have to have an adaptor to connect one end of the cord because of the differences in the plug configurations.

I agree with John on the 50/30 amp connection inside of the camper.

I would suggest that having the fewest number of cords, adaptors, and connections possible is the preferred way to go.

As for the 22 amp draw, that is the constant draw amps. A bad connection can fail at a lot less than that. When the AC compressor kicks on it will cause a momentary current surge. Once running, it will settle down to something less. Your washer/dryer will typically draw more current when it is drying than washing. So you could be pushing it but your circuit breakers are designed to kick you out if you overload.

Never hook a 50 amp source up to a 30 amp cord.

[BB_TX]

The weak link was the 30 amp receptacle, not the cord. Even if you had used the 50 amp cord with a dog bone adapter, you would have had the same problem. A poor connection in the 30 amp receptacle causes resistance, and resistance causes heat. So you would have burned your adapter instead of your cord.
Part of your Monty is wired to one leg of AC hot and the rest wired to a second leg of AC hot. When using 50 amp service, whatever is being used at the time draws power thru its respective leg. But when using 30 amp service, both legs are tied together in the 30 amp cord or in the 50/30 amp adapter and everything draws power thru the one and only leg available.

[Bill-N-Donna]

All good information, thanks!

[KDS MONY]

I always use the 50 amp power cord regardless of what is at the pedestal. If it is 30 amp I just add a 30/50 dogbone adapter. I'd rather burn up the dogbone than a good 30 amp cord. Seems the 30 amp recepticles are often in poor repair at many campgrounds especially older ones, Best wishes, Jay and Kathy

[richfaa]

We do have a 30 amp cord that we keep in the back of the truck for those occasions we are at a rally with 30 amp service only.We use the 50 amp cord at all other times as we want the ability to run everything if we so choose.

Right now the main A/C is running on leg one drawing 13 amps and the dryer is on the dry cycle drawing 17 amps on Leg 2. The fridge is on ac. the Tv is on.The Pc is on and that is about it. We are drawing 30 amps total on the two legs.. If we were on a 30 amp cord and we turned on one more light we would be dark.

[mhs4771]

Rich, I'll bet that if you were on a 30 amp service, you would already be dark!

[awaywego]

I have a 30 amp cord to use when that is all that is available. I figure on replacing the male plug once a year due to campground connections being so poor.
I think it is easier to replace the plug on the cord than on the dog bone.
I loaned a 30 amp cord to a neighbor in a campground and he brought it back melted. It was a new plug and he was only using the AC and wh.

[Larry-P]

Okay, I'm a newbee to this sort of thing.
All things being as there are described in this discussion, if I connected the dogbone to the CG 30amp plug & the 50amp end to my surge protector, would the surge protector prevent the plug from melting ??

Larry P

[wersqu]

I use the 30 where 50 isn't available or the 50 won't reach. What I have found also is the adapter between the 50 & 30 bends in the direction of the heavier 50 am cord which twists the 30 slightly causing it to burn/melt. This happens most in cold weather when there is little flexibility in the 50.

[HOOK]

I have an adapter that is configured as a "Y". The long end is 50 female. One leg is 30 and one is 20. I also have a 30/20 adapter. Most pedestals have 50, 30, and 20 receptacles. The adapter is approx. 3 feet long and weight does not have a great effect. In the past I have had plugs melted on SOBs that only had 30 ser. The pedestal is always an unknown, so if you can support the weight of your cord by using a bungee or any good idea to prevent twist it is good. Larry

[mhs4771]

Larry P, most likely not, since the surge protector would be after the 30 amp plug. As mentioned most likely the 30 socket had been burnt from numerous plug-in/un-plugs with power applied plus just the constant usage creating less pressure from the contacts all makeing for increased resistance and the by-product from the resistance it heat, thus things melt. The surge protector is there to protect things down stream, in our cases the Monty.