Heat aand dropping voltage

[TimeTraveler]

Temp today is over 100 headed to 108+. Voltage on 50 amp cord when  it gets warm drops into the red wit the two ACs running. The cord is extend about 25 ft to the 50 amp plug.

Even the water into the coach is hot enough for a shower.

We cannot run the convection/microwave on that and may be endangering the heat pumps.

I turned on the generator and all is good but don't wish to do it until the temp  drops down to 90 or so after dark...unless I have to

I don't know if the circuits in our Relative' garage and home, where we are plugged in are that low or not.

First instinct is that the cord is getting too hot and causing the voltage.

Anyone else noticed this and how did you shield the cable and did that work, or did you do something else?

Edited August 14, 2020 by TimeTraveler
more info

[kaypsmith]

Start by checking voltage at other plugins at your location, not in the RV. What gauge wire is the cord that you are hooking the RV to the plug? 50 amp needs to be 6 gauge for the two hots and neutral 8 is ok for ground. If wiring is correct and voltage before the plugged cord to RV is ok, then an inspection of the box that you are plugged into needs to be checked for bad possible connection, and for proper wire size feeding the box, if too small there can cause problem as described also. If all these are ok, check to make sure the AC's are not pulling more than their fair share, most roof airs only pull a maximum of 12 to 15 amps, and usually will trip a breaker if they pull more. Also the breaker that fees the 50 amp may have loose wires or may not be properly seated.

[wildebill308]

What is the voltage on your surge guard on each leg? I bet you have low voltage where you are plugged in.

Bill

Edited August 15, 2020 by WILDEBILL308

[txiceman]

If your voltage at the pedestal is under about 112 volts on either leg with no load on the circuit, you will have problems with the low voltage in the coach when the A/C is running.  Most A/C units do not like to operate below 108 volts.

If you are operating the RV fridge on electric, switch to propane.  Same goes for the water heater.

The problem with campgrounds now is a lot of them are older and the wiring was not set up for an many big rigs as they get now.  Check the voltage on other sites in the park if they are not occupied.

If you are mooch docking and powered from a garage circuit, other loads on the circuit can drop the voltage.  But first thing to do is to check the voltage at the power source.

 

[rayin]

As Ken said, nominal voltage in the U.S.A. is 120VAC, plus or minus 10%. Outside those parameters inductive motors are slowly being damaged - permanently. It's called "bruising", an analogy would be: you are hit on your shoulder repeatedly,  each time hurts worse, until you can't use your arm/it fails to operate.