Generator or converter problem??

xraymiller · 10-15-2021, 04:27 PM

I'm driving home and while at a rest stop wanted to run the A/C so I started the generator. It cranked and sound like it was running without any issues; however, it seems like I wasn't getting the power to run the A/C's, microwave or inverter (stayed at 12.3 volts instead of the 13+ I usually get). Also, I heard a kind of sputtering (or something trying to catch but couldn't, separate from the generator) every 10 seconds or so coming from under the master bed. My guess is the converter. Any idea what might be causing and/or possible fixes?

At the next stop it took about 5 minutes or more before it kicked over and I was able to run the generator.

Grumpy · 10-15-2021, 04:52 PM

Sounds like low geny output or a bad transfer switch. If the transfer switch doesn't sense the proper voltage it won't close properly. The noise you heard was probably the relays trying to close.

JimD · 10-15-2021, 06:38 PM

No voltmeter measurement = no way of knowing what is happening. For now, ignore the converter, inverter, and everything 12 volts. Your problem is in the 120 volt side of things.

If you can do a shore power hookup that would tell you if the problem is generator related. You may be getting low or no output from it. I would think if it was low it would be trying to speed up to compensate and sound weird.

Anyway, plug a voltmeter into any power outlet and fire up the generator and measure what is being fed to your rig. This will tell you a lot and then things can be narrowed down.

I have attached some basic troubleshooting documents that may shed light on things.

Mike-NM · 10-16-2021, 08:59 AM

Most likely the automatic transfer switch....is having a difficult time making the connection or going bad. Are you in Florida? If so, your contacts are probably corroded. If you have not used it in a while it could have pitted the contacts or the wires may be loose enough for an unstable connection which will ultimately get too hot and melt the connectors. What year make and model of your unit?

Here is a decent video explaining the transfer switch.... skip to 9:20 to get to the transfer switch.

https://www.youtube.com/watch?v=7xxWagd-Q8Q

xraymiller · 10-16-2021, 02:33 PM

On shore power everything is fine. I will try what you suggested, but I do have a question. If the inverter shows 12V instead of the higher 13V when hooked to shore power or the genie running with things on as normal, I would suspect that I will not get any reading off the 120V outlets. Isn’t it all or nothing? Either the relay or transfer switch is on or it’s not?

Thank you for the manuals, I will add them to my RV Book of Knowledge.

Grumpy · 10-16-2021, 02:35 PM

The INVERTER is reading your battery. No connection to 120v.

xraymiller · 10-16-2021, 02:48 PM

I do live in FLorida and although we keep the RV plugged up to the house with the A/C’s set to 80 and keep a dehumidifier on, I think you're right. At least from my observations it sounds as if the transfer switch is having a difficult time connecting.

I have to take the RV in to have LazyDays in the Villages to fix my macerator leak (that they didn’t fix last time even though I was charged) so I might have them check that out.

xraymiller · 10-16-2021, 03:07 PM

I understand that. Let me rephrase, when the genie is on and the 120V is flowing, the batteries are being charged and the inverter shows 13+ volts. So when I'm not getting the power from the genie I don't get the 120V, the batteries are not being changed and the inverter shows 12 volts. It seems to me the two things are related.

JimD · 10-16-2021, 03:37 PM

Quote:

Originally Posted by xraymiller

I understand that. Let me rephrase, when the genie is on and the 120V is flowing, the batteries are being charged and the inverter shows 13+ volts. So when I'm not getting the power from the genie I don't get the 120V, the batteries are not being changed and the inverter shows 12 volts. It seems to me the two things are related.

The converter is powered by either the shore feed or the generator feed and will produce the 13+ charging volts for the battery. The inverter is connected to the battery and can display the battery voltage.

Seems like the generator is not outputting voltage to the converter which would result in the lack of charging voltage. The inverter is simply acting like a voltmeter on your 12 volt supply.

The transfer switch is controlled by the generator meaning that when it senses generator voltage it will switch to the generator feed. It is nothing more than a heavy duty relay. When the generator is on, "click" it connects the contacts to the generator. Generator turns off and "click" it now returns to the shore power connection.

Here is a very simple test to see if it is switching states. Connect to shore power and look at your inverter display. I assume it will be showing charging voltage. Now, while still connected to shore power, fire up the generator and look at the inverter display. Don't worry about having both power feeds at the same time as they are totally isolated from each other and won't interact at all. I do this all the time when I run a small inverter generator on my shore power line and then temporarily fire up the big generator to run a microwave or whatever. It switches over to the big genny and then when I turn that off it returns to my little genny.

Anyway, I will guess that the voltage displayed on the inverter will still show a charging voltage because the transfer switch will not have changed position. In this case you would still be connected to shore power and the generator would be doing absolutely nothing.

If all of this holds true you either have no generator output or the transfer switch is bad. The first thing I would do is reset the circuit breaker on the generator itself. If it is tripped you will have no generator output.

The actual power output can be measured inside the transfer switch but I do not recommend a novice poke around inside there as there are lethal voltages involved. The simple check with both power feeds at the same time is completely safe and may give some additional info.

xraymiller · 12-05-2022, 09:31 PM

Sorry, I thought I made a follow-up on this problem. While on my trip from Florida to Maine I noticed the problem seemed to happen more when I was further south so I started thinking about what I was doing differently. I tested my theory at different stops and at the very least I found a work-around.

What was different was the A/C units had the fan set to ON. Normally if I was hooked up to power the A/C’s fans would come on as soon as I turned on the breaker. When we were in warmer climates, I had the fan set to ON all the time, but the further we went north the A/C’s were off and I used the heat. I think it was trying to draw too much power immediately which was causing the system not to switch over to the 120V.

I tested my theory at every stop on the way home and I did not have the problem again. There may still be an underlying issue, but it works and I don’t have to take it in for service.

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