Air Conditioner Failing?

[Country Campers]

So I did a test when I got home, got the wife involved also, unfortunately I did not get the results I was hoping for.

I have the RV plugged into a 20 amp circuit thru a power strip with a reset on it, not sure what amperage it is. I started the AC and waited for it to cool and was watching the BMV as well as the Touch 50. When I had the wife turn the power strip off nothing happened the AC kept running. Puzzled I had her turn the shore power back on and noticed on the Touch 50 that I was in the "Assist" mode so the Inverter was already helping so there was no power "spike" to cause an issue. Going into the Touch 50 I had the incoming power set to 15 amps so with the AC on it was in Assist mode. I changed the input power to 50 amps and tripped the power strip where the camper was plugged in to. What does this mean? Did I learn anything? I am not sure. I will have to try on a 50 amp shore power site and see, sorry I do not have 50 amp here.

Brian

[howson]

Country Campers -- sounds like your setup is working perfectly.

[ncitro]

howson Interesting thought on the waveform. Never occurred to me since it's commercial power, but I've seen stranger things in the field. I know one of our three phases comes from a different pole than the other two (drunk driver took down the pole and we only lost one phase), and we occasionally drop a phase so it certainly could be. One of my guys has a scope, next time he's in the shop I'll check it out.

[Country Campers]

howson Interesting thought on the waveform. Never occurred to me since it's commercial power, but I've seen stranger things in the field. I know one of our three phases comes from a different pole than the other two (drunk driver took down the pole and we only lost one phase), and we occasionally drop a phase so it certainly could be. One of my guys has a scope, next time he's in the shop I'll check it out.

When checking this you will be looking for the "wild" leg, noted in most 3 phase wiring, one leg will be a little more "juicy" than the other 2. I think in our shop we do not use that leg for our single phase 120 v outlets.

Brian

[ncitro]

When checking this you will be looking for the "wild" leg, noted in most 3 phase wiring, one leg will be a little more "juicy" than the other 2. I think in our shop we do not use that leg for our single phase 120 v outlets.

Brian

Yeah some setups have a high B leg that gets you 277, I've seen that in the field when installing equipment but I'm pretty sure we don't have that. I think you get that with 480v when wired with a wye transformer or Delta with the extra high B leg. My physics was a while ago lol. I'm pretty sure our shop is wired for 208v three phase, so all phases should be the same but I'll definitely check.

[ncitro]

Just to wrap this up, seems like the issue was of my own making. I did the checks howson recommended, the waveform of our AC power here is rock solid, on all three phases. Frequency is right at 60hz. I tried disabling the UPS feature as well as adjusting down the PowerAssist boost factor after reviewing the Victron forums. I even changed my AC start capacitor on a whim. No luck with any of those. One time while starting the AC, I noticed my backup converter (installed from an issue a long time ago with the charging side of the MultiPlus) came on when the inverter was running. I keep this on L2, which is not connected to the inverter, and usually have the breaker off, but had turned it on to use the outlet in the front bay for something else. It was running because I was on shore power with it dialed way back to test the power assist, essentially I was inverting L1, and L2 was running off of shore power, running the converter. I turned it off any everything with the AC worked as normal. Power assist no problem, regardless of the current setting. Never did get an error on the MultiPlus, on either the Cerbo, VRM, or with the laptop connected. All I can figure is there was something funny with the converter running, a weird transient, or voltage mismatch. I did not have the scope with me so I could not check, but regardless that seems to have been the issue.

Thanks everyone for the idea bouncing.