50A trailer, 30A cord, 50A pedestal

pete100 · 04-26-2018, 01:36 PM

I have a situation I haven’t come across on this forum. My trailer came prepped for a second A/C and is wired for 50A. I’m never going to add a second A/C and at my age don’t like manhandling the 37’ 27 lb. cable. I bought a 25’ 30A cable that plugs into my 50A trailer connector and also to pedestal 30A service. I also have a 15’ 30A extension. The 50A cable stays home. So far nothing out of the ordinary here.
There may be times, however, when only 50A pedestal power is available in which case I will use the 50A-30A adapter I also bought. I believe this configuration will work fine as long as I don’t draw more than 30A since there isn’t a 30A breaker to trip to protect the 30A cable. I will need to carefully manage the power but I have done this before with a sailboat.
Anyone use this configuration?

5picker · 04-26-2018, 02:05 PM

People use 50a to 30a adapters all the time.
Your situation is a bit different than most.

Most folks who use a 50a to 30a adapter do so using a R/V with a 30a service/breaker box. Because of that, they can't feasibly draw more than 30a from the R/V and therefore, the 30a cord isn't at risk of overload. (there will be those who advise of risk or damage to the 30a cord if the cord somehow gets cut/shorted while connected on a 50a service but none the less, the adapters are readily available and legal to use)

Since your R/V is a 50a service, the weak link in the chain for your situation is the fact you are going to be using the 30a extension cord and TWO adapters. (one to adapt down at the pedestal and another to adapt up at the R/V with the 30a cord in between)

Since you have the capability to draw more than 30 amps from things in your camper and since the pedestal is protected by a 50a breaker, that could put your 30a extension cord at risk of overload.

While you 'could' use it if you were careful of your overall amp draw, I can't go on public record and recommend it.

rsdata · 04-26-2018, 02:22 PM

are there campgrounds that offer 50A power only? I would be surprised unless it was a high-end resort situation. I don't camp at those places... Then just cart your 50A cord also.

**ependydad** · 04-26-2018, 02:31 PM

Quote:

Originally Posted by rsdata

are there campgrounds that offer 50A power only? I would be surprised unless it was a high-end resort situation. I don't camp at those places... Then just cart your 50A cord also.

Nah, it's not high end places. High end places often have the pretty boxes but they still have all 3 outlets (50/30/15).

The times that I've seen it are at the Elkhart Campground, at a fairground, and at a little dump of a place right on the highway in Lafayette, LA (which I think is now closed).

xgarys · 04-26-2018, 04:00 PM

Quote:

Originally Posted by rsdata

are there campgrounds that offer 50A power only? I would be surprised unless it was a high-end resort situation. I don't camp at those places... Then just cart your 50A cord also.

I was surprised to only have 50 amp service at Craters of the Moon KOA. They have loaner adapters.

fonzie · 04-26-2018, 04:06 PM

You could change your 50 amp double pole breaker to a 30 amp double breaker in your distribution panel and all will be protected properly.

doc73 · 04-26-2018, 05:28 PM

I might be wrong, new to the 50amp world, but if he did that (my panel is at least) split in the middle with half the lads on each leg. By going to a single pole he'd loose power to half the camper. We had one A/C as well but it was still split down the middle.

fonzie · 04-26-2018, 05:37 PM

Quote:

Originally Posted by doc73

I might be wrong, new to the 50amp world, but if he did that (my panel is at least) split in the middle with half the lads on each leg. By going to a single pole he'd loose power to half the camper. We had one A/C as well but it was still split down the middle.

I did say a double pole 30 amp breaker....but if load is distributed across both sides, then he could still pull more than 30 amps on the power cord. Need to see what is hooked to his distribution panel to give more appropriate information.

doc73 · 04-26-2018, 05:41 PM

Quote:

Originally Posted by fonzie

I did say a double pole 30 amp breaker....but if load is distributed across both sides, then he could still pull more than 30 amps on the power cord. Need to see what is hooked to his distribution panel to give more appropriate information.

you did... my apologies. I saw 30amp and my head just ignored the whole double part... but yes he'd be able to pull 60amps total (30 from each "leg") so still overloaded.

formerFR · 04-26-2018, 05:48 PM

I actually don't think you'll run into very many, if any, '50a' only campgrounds or rv parks... and if there are any, it's probably not where you're going... so it's doubtful you'll ever need your adapter, regardless... use 30amps and enjoy : )

you probably already realize,though, that '50a rv service' is actually 100amps of available power(two 50a lines of power)... so you are 'giving up' 70amps, not just 20, when you adapt 'down' to a 30amp power outlet.

**ependydad** · 04-26-2018, 07:28 PM

Quote:

Originally Posted by formerFR

I actually don't think you'll run into very many, if any, '50a' only campgrounds or rv parks... and if there are any, it's probably not where you're going...

Pssst.... scroll up. We listed 4 places.

But, I do agree it’s pretty rare.

**ependydad** · 04-26-2018, 07:30 PM

Quote:

Originally Posted by doc73

you did... my apologies. I saw 30amp and my head just ignored the whole double part... but yes he'd be able to pull 60amps total (30 from each "leg") so still overloaded.

Heh. I came REALLY close to posting the same thing before re-reading the double-pole breaker.

I did wonder if you could build something that you take a short piece of 50amp cable to a 30amp breaker and receptacle. Install this closest to the camper.

It wouldn’t weigh much but would allow proper 30amp protection.

Moosey1 · 04-26-2018, 08:16 PM

My friend, with this setup, you just gave your insurance police a way to skip out of paying you for any, I repeat any electrical damages using this set up.

Cypressloser · 04-26-2018, 09:09 PM

IMO, anything downstream from the pedestal should be rated for 50 Amp if the pedestal supplies 50 Amp and the trailer is wired up for 50 Amp or else, at one time or another, someone turns on another appliance and melts the 30 Amp 10 awg? cable or the cable ends burn up.

You should, as was recommended, replace the 50 Amp breakers in the trailer with 30 Amp or have a 6 awg 2 wire extension cord with the proper ends professional made which doesn't really make sense from a cost and weight savings perspective.

Another option to save on back breaking work would be, if you're willing to spend a small fortune, a powered cord reel.

LegacyFB38 · 04-26-2018, 09:16 PM

It seems to me that replacing the 50A breakers in the RV with 30A will leave the possibility of 60A being drawn from the 30 A cord.

Cypressloser · 04-26-2018, 09:39 PM

Quote:

Originally Posted by LegacyFB38

It seems to me that replacing the 50A breakers in the RV with 30A will leave the possibility of 60A being drawn from the 30 A cord.

No, because only one single 30 Amp rated wire, protected by (2) 30 Amp breakers would be connected, same as if he would plug the trailer into a 30 Amp pedestal.

LegacyFB38 · 04-26-2018, 11:22 PM

Quote:

Originally Posted by Cypressloser

No, because only one single 30 Amp rated wire, protected by (2) 30 Amp breakers would be connected, same as if he would plug the trailer into a 30 Amp pedestal.

If I'm visualizing this correctly, L1 and L2 in the trailer (originally wired for 50A) would now each be protected for 30A. They would then be tied together by the adaptor/power cord. This would allow a combined maximum of 60A.

To add to the confusion, at the pedestal the power cord plug/adapter would only be able to connect to L1 or L2...otherwise there would be a dead short across L1 and L2.

So, the pedestal would limit total current to 50A.

5picker · 04-27-2018, 05:19 AM

50a is the max amperage that would be phisically supplied.

The adapter at the pedestal would connect to one 50a leg.

The adapter at the R/V would connect that 50a leg to both sides of the R/V's breaker box.

Doesn't really matter whether they replace the R/V's 50a breakers with 30a because the capability to draw from both sides of the box could allow up to 60a of load to be connected (even though there is only 50a available) and still exceeded the rating of the 30a extension cord.

youroo · 04-27-2018, 05:52 AM

Quote:

Originally Posted by ependydad

Pssst.... scroll up. We listed 4 places.

But, I do agree it’s pretty rare.

Heck we have been to "Resorts" where the sites were Double 30s Only and the next site was Double 50s Only! Also a Ocean Site that Only had a 20 on a Tree!

Nothing Surprising in the RV world!

Youroo!!

formerFR · 04-27-2018, 07:39 AM

I think the smartest thing, in light of your concerns about 'ever' running into a 50a 'only' campground or rv park, is to carry/store your 50a cord, for those 'once in a lifetime' scenarios.
Your whole original post was the concern of not having to 'handle' the weighty cord, but if you hardly ever have to use it, you've help solve the situation without doing anything different or unsafe for power.

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