Strange amp readings - 2000 Vantare H 3-45

[D Lowe]

The coach is set up to run 2 A/C's on each leg. Sometimes it will be pulling about 35 amps per leg which seems about normal. Other times it will show 50+ amps on one leg and 0 amps or close to 0 on the other leg. At that point I have to shut down one A/C or it will for sure blow a circuit breaker. I never know when it is going to be normal. Sometimes it will stay OK for days and other times it may be abnormal from the moment I turn on the A/C's. When it is abnormal it will still be showing all the amps on one leg even when I turn all the A/C's off. Any ideas what is going on?
D Lowe, 2000 Vantare H 3-45, 2 slides

[Mark3101]

Where are you seeing this? On an inverter panel, or a dedicated voltmeter? I don't see how you can get a load to jump to another leg without something shorting out. Are you having any other issues with your electric systems?

[Jon Wehrenberg]

D,

All our coaches should be set up so if we have four AC units they are split between the 2 120V legs. Your amp draw with all four ACs on at about 35 amps per leg is what I would expect to see.

I think your coach has all of the electric circuits going through the inverters instead of just certain dedicated circuits. Is it possible one of the inverters is dropping off line? I am just guessing because I cannot think of any reason why only one leg would start carrying all of the load and the other leg none of the load.

[nrhareiner]

When you are seeing the amp draw being uneven, is one inverter bank showing the amber light indicating not in float charge mode, while the other bank showing 2 green lights? If yes then check and see if one inverter is reading float charge with inverter amp reading a negative 9-15, and the other leg reading a charge rate at the same value on the positive end of the scale. Then check amount each leg load versus input and that may get you the answer as to what real draw from pedestal is looking like. Hope this helps.

[D Lowe]

I'm seeing it on the inverter panel in the coach. I have a dedicated voltmeter but haven't tried that yet. I don't believe anything is shorting out. This is the most serious issue I'm seeing but I don't think my electrical system is acting just right. Another response I received suggests it may be an inverter problem and I'm leaning that way myself. I don't fully understand the system in the Vantare but I think everything goes thru the inverters.

[D Lowe]

I'm beginning to lean toward thinking this way. The inverter doesn't seem to be dropping off line but it doesn't seem to be carrying the load. This is giving me some ideas to try.

[D Lowe]

Yes. one inverter will be in bulk charge and the other is in float just as you describe. I will check as you suggest. Are you suspecting an inverter is causing this?

[D Lowe]

Just returned from the coach after reading these posts. I've been in Prevosts for a long time but I'm still learning things, some of it that I knew in the past & had forgotten. I realized this bus has a manual switch to bypass the inverters. When I did that and turned on all 4 A/C's I was only pulling between 28 & 30 amps on each leg which is what I consider very normal. I've owned this bus 4 years and I don't believe the house batteries have been changed in that time. I believe that I have some bad house batteries because when I bypassed the inverters one inverter immediately showed to be in float charge and the other one was in bulk even though it had just before switching been in float also. Am I on the right track?

[Jon Wehrenberg]

D,

One thing we all learn is that batteries have a significant impact on the function of inverters.

I have zero knowledge of Vantare so I don't know if they split the batteries up into two separate circuits or if they are charged as a single bank, but one bad battery can have a major impact on charging loads. If you are not sure of the battey condition or age separate them and test them individually. It is possible one or more are bad.

If that is the case replace them all as a set. Our own guy Truk can help you with your battery purchase.

[nrhareiner]

Vantare does have an unusual circuit for charging, each battery bank is not connected to a single inverter. If possible do an easy test. Turn off all A/C units for around 2 hours (may want to do this at night if not too hot where you are. I think all will be green in the AM.