RV Power Monitor

Introduction: RV Power Monitor

About: I am currently converting a 1988 40' Bluebird school bus into a motor-home / workshop that I plan to live, work and travel in. This is my second such project. This one will probably be my retirement home. Sti…

I wanted to be able to monitor my RV power grid from the drivers seat and anywhere in the bus. So the wheels got to turning again.

Step 1: Supplies

This is a very simple and inexpensive project. However it can save considerable hardship and foresee problems. Total cost for this was less that $40.00.

Step 2: Mount Your Meters

I couldn't find a blank 4 gang wall plate, (I didn't really look that hard). So I purchased a 4 gang switch plate. Start by mounting your meters in whatever configuration you want them. I drew the pattern on the back of the switch plate and used a multi-tool to cut out the squares. You can also do this with an X-ACTO knife. Make constant checks for fit as there is not much lip holding the meters in place. The good part is that the switch plates are so inexpensive that if you cut the opening too big you can start over. This is important as you don't want these things to move or shake lose while you are driving.

Step 3: Wire Them Up

On my setup, the top meter monitors the house battery. The second meter from the top monitors the chassis battery. The third and fourth meters from the top monitor each leg of the AC circuits. I can see this while I am driving and from most anywhere in the bus.

Step 4: Reasoning

In the DC circuit:

  • I can watch the to DC monitors and tell how my battery levels are at any given time.
  • I can also tell if my battery isolator is operating properly.
  • I can see the need to shut something down if the low voltage alarm or cut off should fail.

In the AC circuit:

I used two AC meters so I can tell if I am on a 240 volt line or a 120 volt line tied to both legs of my 240 volt wiring. This is good to know if you have two air conditioners in your unit and want to run them both. If both numbers always remain the same no mater what you turn on, you are most likely sharing the same 120 volt line. When you turn on a heater, AC, water heater or any electric appliance with considerable current drain, one line should be slightly lower than the other. It may only be a volt or two but it should be different.

If you have 30 amp service you should only need one AC meter.

As usual there is much more to come. Check back often or signup to follow me. You can follow my entire school bus conversion and my travels at leonardsteward.com.

Thanks for looking,


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