50A to 30A Source Distance Limitation

Hi,

I'd recommend checking the voltage drop under load at the 30 amp source. You may find that it drops off more than expected.

I check voltage with a 1500 watt heater running.

deercamp01 wrote:
Thanks for the good input. Regarding source voltage, I verified the source voltage is stable and 120. I agree having 50A service end to end would be preferred but unfortunately limited with 30A source service so I need to either "jumper" the end or use a converter plug at the source end (50A female to 30A male).

Thanks again for the guidance!

deercamp01 wrote:
Regarding source voltage, I verified the source voltage is stable and 120. I agree having 50A service end to end would be preferred but unfortunately limited with 30A source service so I need to either "jumper" the end or use a converter plug at the source end (50A female to 30A male).

If your unloaded source voltage is reliably 120 vac and you're planning on a maximum 30 amp load then you could actually do fine with 135' of 10 gauge rather than more costly 50 amp 6 gauge. Sure, voltage drop will exceed the nominally recommended max of 5% but you'll still be seeing ~ 112 volts at the camper under full 30 amp load. I in fact sometimes do this here in Ontario where runs to the campsite power post can often be quite long indeed. I carry ~ 140' total of 10 gauge main service cable and do find myself using all of it from time to time, 'though I typically don't draw anywhere near a full 30 amps at any time, usually 20 amps or less. It can be done though.

As far as connecting to that 50 amp service is concerned I'd just use a standard 50 amp male > 30 amp dogbone at the supply end to feed your 135' of cable. :)

I run a 100 ft. 10AWG cable from distant 30A sources to my 50A RV with very little problem as long as the shore power pedestal voltage is at least 120VAC. Make your cable a true 30A extension and use your 50A-30A adapter at the RV end. I do that often.

Thanks for the good input. Regarding source voltage, I verified the source voltage is stable and 120. I agree having 50A service end to end would be preferred but unfortunately limited with 30A source service so I need to either "jumper" the end or use a converter plug at the source end (50A female to 30A male).

Thanks again for the guidance!

deercamp01 wrote:
We have a 50A RV at our deer camp which provides a 30A dedicated connection. The RV is approx 135 ft from provided power (cannot move RV closer). My plan is to run direct buried 6AWG cable with a 50A female plug on one end (RV) and a 30A male plug on the other end (source).

Besides limiting us to a single AC unit, are there any other issues we might encounter with this design?

You haven't specified unloaded source voltage which nominally should be 120 vac +/- 5% or 114 vac to 126 vac. Unfortunately reality doesn't often meet expectation and if you start with an exceptionally low unloaded source voltage the situation will only get worse once you do add a load so regardless of the fact you're planning to use 6 gauge cable resulting voltage drop could still be sufficient to cause problems. IOW, have you verified what the unloaded source voltage typically averages at this deer camp?

csamayfield55 wrote:
You don't want to do that. You will only have one half of your trailer with power. You need an adapter to cross over to both legs of the 50 amp plug or only half the power panel in the rv has juice. You may be able to jumper one leg to the other in the plug but i am not going to tell you how to do that.

As far as distance goes, all depends on the amps your going to draw. I don't have an ugly's wiring in front of me to check runs but 6 gauge seems large enough as long as the supply wasn't wired with substandard wire to start with

Chris

I'm assuming, and yes we know how that is, that he is tying the two hots together to the one source and in effect is making a 50 ft long dogleg.
bumpy

You can jumper the two hots in the 50 amp female. That is what a 50 to 30 adapter does.

You don't want to do that. You will only have one half of your trailer with power. You need an adapter to cross over to both legs of the 50 amp plug or only half the power panel in the rv has juice. You may be able to jumper one leg to the other in the plug but i am not going to tell you how to do that.

As far as distance goes, all depends on the amps your going to draw. I don't have an ugly's wiring in front of me to check runs but 6 gauge seems large enough as long as the supply wasn't wired with substandard wire to start with

Chris

Without knowing the construction of the source circuit and how much power it can allow with permissible voltage drop, we would all be guessing.

AWG 6 will certainly be within 5% voltage drop for the 135 ft. of run stated.