by Barry and Cindy 1997 U270 36′
These ideas are based upon our 1997 U270 Motorhome configuration…
Our 8000 watt Power Tech generator generates 110 volts that leave the generator control box after being wired through two separate 35 amp circuit breakers that are mounted on the generator control box. One of these circuit breakers could be weak and not holding. Try to switch them off and on several times.
When one side is not working, open the generator control box and put a meter on the output of the circuit breakers to see if one is zero volts. These circuit breakers could be bypassed with a wire nut and tape if one is bad until you get a replacement.
Now on to transfer switch (ours is under the bed).
Disconnect shore power (I know you are dry camping) & keep generator off. Open transfer switch box.
Our transfer switch has two relays inside, one for shore and one for generator. There is a mechanical plastic part that prevents both transfer switches from closing at the same time.
Figure out which relay switches generator wire feed. It’s the same situation if you only have one relay. Make sure all screws holding down all wires are very tight. Take a piece of emery cloth or fine nail file, etc and clean points on relay. Do not remove much metal as there is a coating on the points. When you have the failure, check wires in and out of the relay to see if the problem is there.
Now onto main circuit breaker panel…
Our panels are the same ones used in homes and have two copper vertical bars to which circuit breakers are connected. Since it seems that all of one side is failing at the same time, I don’t think it is any of the individual circuit breakers in the panel.
With all current off, tighten real tight, the main red and black wires on the main circuit breaker (and all other screws while you are at it). Switch on and off this main breaker as it could be the problem. You could remove and replace the main breaker so the backside connections to the two copper bars get a renewed connection. Clean anything you want with emery cloth or file. No coatings here to be careful of.
After using emery cloth anywhere, clean the area by blowing, etc to remove any emery particles, if possible. During a failure check the main circuit breaker wire screws and the copper bars to see if zero volts show up.
A bad connection may show up as some voltage above zero, but not around 110 where it should be. This would be caused by a high resistance connection caused by a dirty or loose connection or failing switching part.
In our motorhome and in your stick home the incoming electricity is made up of two separate 120-volt hot wires (red & black) and one common neutral (white) plus a safety ground that does not carry any current (green)?
So in our homes, we have two separate 120 circuits and one could go out and one could still work. What is on one side or the other is determined by the location of the individual circuit breaker in the main panel. Usually, every other breaker is on the same input wire. I made a list that I have hanging inside a kitchen cabinet that shows what is on leg 1 and leg 2. I use this list to turn off somethings before I turn on other things if the electric voltage is not strong.
By the way in a stick home, 220-volt appliances like an electric clothes dryer or electric stove or electric hot water heater get its needed 220 volts by being connected to just the red hot and black hot, not the white neutral. Motorhomes do not have any 220-volt appliances since 220 volts is not available in all campgrounds.
Each 120-volt outlet is connected to one hot side and one common neutral to supply the energy for our appliances.
Since only one side is going out, it does not sound like the problem is on the neutral side of things.