Power Management - Line 1 Line 2

[vegasmun]

2012 Winnebago Tour plugged into 50 amp service. It's hot where we are, from morning til night. Came back to RV park to find rear A/C not working and circuit breaker flipped off. Flipped breaker back on, cycled the three A/C units off, eliminated all other noticeable draws, cycled three units back on, so far so good.

Please understand I know next to nothing about electrical. My portable EMS and on board EMS, right after cycling units back on and all three units kicked in, read L1 115v @ 44 amp and L2 118v @ 5 amp. I assume the energy management system did it's thing and eventually the readings were L1 115v @ 33 amp and L2 117v @ 5 amp.

Questions:

So low voltage is likely a result of the heat and power draw from the packed RV park? (Very nice, modern RV park.)

So I'm assuming only two of the three units are now working at any one time. Which seems to indicate that all three units work off of L1? I thought the idea was to spread the load between the two lines?

Any info, insight, education or what to do would be most appreciated!

 

[jerichorick]

2012 Winnebago Tour plugged into 50 amp service. It's hot where we are, from morning til night. Came back to RV park to find rear A/C not working and circuit breaker flipped off. Flipped breaker back on, cycled the three A/C units off, eliminated all other noticeable draws, cycled three units back on, so far so good.

Please understand I know next to nothing about electrical. My portable EMS and on board EMS, right after cycling units back on and all three units kicked in, read L1 115v @ 44 amp and L2 118v @ 5 amp. I assume the energy management system did it's thing and eventually the readings were L1 115v @ 33 amp and L2 117v @ 5 amp.

Questions:

So low voltage is likely a result of the heat and power draw from the packed RV park? (Very nice, modern RV park.)

So I'm assuming only two of the three units are now working at any one time. Which seems to indicate that all three units work off of L1? I thought the idea was to spread the load between the two lines?

Any info, insight, education or what to do would be most appreciated!

I am having a bit of trouble following you. Some of this may be due to the eye surgery I had the other day. lol

If the compressors on all three units are running you will have a 14+A draw on one leg and a 28+ draw on the other. If just the fans are running these readings are much lower. This is all true when on 50A service. Things change on 30A service.

On 30A service your Power Control ... Panel plays a greater roll in keeping your essentials functioning on this limited power. When you scroll through the screens with the up or down buttons you can see what loads are shed. You will never be able to run all 3 A/C units at the same time on 30A. If you run the microwave you will lose the water heater (on AC) for the duration of the microwave cycle and be able to run 1 A/C unit. (This is not the best example because the inverter will supplement the microwave.)

The breaker probably tripped because you either went to brownout voltage and the EMS didn't respond quick enough, or you are having connection issues in the wiring someplace. On 50A the EMS should respond to any brownout condition by isolating the coach from the shore power. I have had this happen a few times over the years.

I suggest that you learn where all of your AC connections are made. This sounds worst than it is. You have the ATS located where the shore power cord connects to the coach, your on board service panel/sub panel and your inverter. These are your main AC power sources. All the wires connected to these devices MUST be re-tightened from time to time. Heat and vibration loosen these up.

I recommend that you do the following:

-Disconnect from shore power.
-Shut off the breaker at the generator.
-Remove the cover of the ATS (Automatic Transfer Switch) and tighten all of the terminals. (Close it back up when done.)
-At the service panel shut off all of the breakers. Remove the cover. Tighten all of the screws on the buss and the breakers. Put the cover back on and turn on the breakers.
-Set the generator breaker back on.
-Connect to shore power.

I often find the neutral loose for some reason when I do this routine. Another common problem is with the shore cord plug. I recommend cleaning the prongs from time to time with fine sandpaper or emery cloth and then apply a fine coat of anti oxide compound, found at HD, Lowe's, a hardware store, etc in the electrical department.

I hope I have been helpful to you.

Happy trails,
Rick Y

 

[Superpacer]

We are in an Itasca Ellipse (sister coach to the Winne Tour) and had a similar issue with our rear AC unit. Our issue tuned out to be a bad ground wire to a control relay (at the AC unit on the roof). Jerichorick (above) has suggested a good plan to eliminate possible issues one at a time. Tightening the connections is nearly an annual task!
Enjoy the day,
john

 

[skyking-WO]

Listen to JericoRick. Loose connections happen.
Example: My Adventurer was showing about 12.5 volts charge to house batteries when on shore power. Being an electronics buff, I thought that strange. I found that the power output terminals on the converter (under refrigerator) were very loose. Tightened them with a screwdriver and mirror and all is now well. Over 13 volts when on shore power. I thought that they were never tightened at the factory. Maybe so, but maybe time and travel had an effect as JerichoRick stated.
I'll start checking the other high power connections!