RV voltage drop

[Matt Mckenzie]

What is the lowest recommended voltage to use on a 120 volt 30 amp RV? We have an RV 1000 feet from the power source that is reading 120 volts.

 

[kwired]

Depends on what the lowest voltage any equipment you are powering can tolerate.

An air conditioner will have a lower limit before performance is impacted, an incandescent lamp will just run dimmer but will not hurt anything otherwise

 

[Little Bill]

What is the lowest recommended voltage to use on a 120 volt 30 amp RV? We have an RV 1000 feet from the power source that is reading 120 volts.

Put a small load on it at the RV such as a drill or heat gun and read your voltage again. You will probably see quite a drop depending on the size of the conductors.

That's if I'm understanding what you said. I took it you had a run already to the RV and was reading 120V. If not, just find out the tolerance of any/all items in the RV then use a voltage drop calculator to determine conductor size to meet that tolerance.

 

[kwired]

Put a small load on it at the RV such as a drill or heat gun and read your voltage again. You will probably see quite a drop depending on the size of the conductors.

That's if I'm understanding what you said. I took it you had a run already to the RV and was reading 120V. If not, just find out the tolerance of any/all items in the RV then use a voltage drop calculator to determine conductor size to meet that tolerance.

Pretty sure same OP had another thread asking about how large of conductor was needed for 1200 foot run to an RV. Now he is apparently asking how much voltage drop is acceptable, though he maybe should have asked in the same thread that was already started because it is pretty much the same topic of discussion just one other aspect of the problem that was brought up there.

Matt, if you do have 120 volts while your circuit is loaded you are doing very good or you have very little load. How much your voltage drops after you have a reasonably normal load operating is what your main concern should be. If the load never or very seldom goes over say 15 or 20 amps you will have better voltage drop results then if it actually reaches the 30 amps capability of the circuit quite frequently.

Other things to consider is (in an RV the biggest load is usually AC) the starting current the AC needs just to get it started. You can have some pretty severe drop during startup or even severe enough it fails to start if you have a long run with small conductor.

 

[JFletcher]

114V.

 

[ActionDave]

If my volt meter read 105V or above under full load I would call it a good day.

 

[mgookin]

I think some are misunderstanding what he's saying.
If I'm reading that right, he has a 120V power source 1,000 feet from an RV. In doing his voltage drop calcs, he's asking what minimum voltage he should design for.
And with that information he can see what the conductors cost to run it at 120V vs. buying transformers to boost the voltage then drop it back down.
He needs the comparison to make an informed decision or to show the customer and let them make the decision.

OP am I right? A little off? Totally wrong?

 

[Smart $]

I think some are misunderstanding what he's saying.
If I'm reading that right, he has a 120V power source 1,000 feet from an RV. In doing his voltage drop calcs, he's asking what minimum voltage he should design for.
And with that information he can see what the conductors cost to run it at 120V vs. buying transformers to boost the voltage then drop it back down.
He needs the comparison to make an informed decision or to show the customer and let them make the decision.

OP am I right? A little off? Totally wrong?

Without knowing the exact loads and their tolerances, the standard is a steady state 104.4V (ANSI C84.1).

 

[kwired]

I think some are misunderstanding what he's saying.
If I'm reading that right, he has a 120V power source 1,000 feet from an RV. In doing his voltage drop calcs, he's asking what minimum voltage he should design for.
And with that information he can see what the conductors cost to run it at 120V vs. buying transformers to boost the voltage then drop it back down.
He needs the comparison to make an informed decision or to show the customer and let them make the decision.

OP am I right? A little off? Totally wrong?

Like I mentioned he already questioned large conductors in another thread for this application, and others have already suggested stepping up voltage then back down or having the service brought closer to the point of use. Now he is asking what amount of voltage drop is acceptable, which wasn't asked in the other thread from what I can recall. Probably would have been less confusing if that were asked in the other thread.

Maybe a moderator can merge the threads.

Add: here is the other thread