Community Forums

mikwallace · 01-26-2022, 09:44 AM

My 2013 Allegro Bus 43QRP is stored inside my shop connected to 50amp receptacle plug when not in use. Twice in the last 2 months I’ve found the “Power Monitor System” display indicates “No Service” and the inverter providing power. Both times I was fortunate that the house batteries were above 11v and still providing power to the frig. No breakers (either in RV or shop) had tripped and power at the receptacle was on. The fix was a simple unplug and plug-in the cable at the receptacle or receptacle circuit breaker off then on. Today (the second time it’s done it) before resetting the receptacle C/B or unplugging the power cable, I took the cover off the receptacle power box and checked voltage at the C/B. Voltage was ok. I turned C/B off waited about 10 seconds then on. Power was restored inside RV. After restoring power today I unplugged the power cable then installed my in-line surge protector, just as a precaution.

So, if there’s a momentary failure of incoming power; either an off/on or brown out condition, does the transfer switch sense this and disconnect; therefore transferring power to the house batteries and the inverter? If so, why would the transfer switch not transfer power back to the pedestal once it is available? Or do I have a transfer switch malfunction?

HarryStone · 01-26-2022, 10:00 AM

Transfer switch has nothing to do with the inverter. It only manages power between the generator and shore power. If you are having issues with shore power, I suggest opening up the transfer switch and checking the relays, if you are comfortable working with electricity.

mikwallace · 01-26-2022, 01:25 PM

Quote:

Originally Posted by HarryStone

Transfer switch has nothing to do with the inverter. It only manages power between the generator and shore power. If you are having issues with shore power, I suggest opening up the transfer switch and checking the relays, if you are comfortable working with electricity.

I can open the transfer switch cover. Looks like it is riveted closed.

So my question is:

If shore power cut off then on quickly or there was a quick brown out condition, will the transfer switch relay open and not close allowing shore power to resume?

jkroboth · 01-26-2022, 02:52 PM

I have had issues where my volt meter said the voltage was in the receptacle but nothing to the coach. Ended up a bad breaker that would let the volts show but did not carry any load. could be an intermittent breaker issue. Good luck.

HarryStone · 01-26-2022, 03:48 PM

I believe the transfer switch defaults to generator (I could be wrong), but if so, when you lose shore power, then the relays would kick the transfer switch back to generator, and if they have a problem, may not revert back to shore power.

**Lt Dan** · 01-26-2022, 04:21 PM

Quote:

Originally Posted by mikwallace

I can open the transfer switch cover. Looks like it is riveted closed.

There are a couple of rivets on the cover holding some clamps, but there should be two small screws that hold it in place. Remove those and the cover pulls off. It has to have access as the electrical clamp connections are inside.

arcaguy · 01-26-2022, 04:40 PM

Quote:

Originally Posted by HarryStone

I believe the transfer switch defaults to generator (I could be wrong), but if so, when you lose shore power, then the relays would kick the transfer switch back to generator, and if they have a problem, may not revert back to shore power.

Some are generator priority and some are shore power priority, it depends on what the manufacturer put in. In any case it should detect the source of power and switch to that source, thus the name Automatic Transfer Switch.

RonAz · 01-26-2022, 05:40 PM

I have seen that faulty breaker problem. Shows voltage, but will not carry current. Try a load like a portable heater on the circuit without it being plugged into MH. If it doesn't work reset the breaker. If the circuit is then good buy a new breaker, they don't really cost much. Before buying a new breaker, make sure that the wire leads are tight "after you remove the breaker from the bus bars". Start looking for the problem at only one end, not in the middle.

mikwallace · 01-26-2022, 07:31 PM

Thanks everyone!! Lots of good information. One problem is that it's not consistently malfuntioning - yet. I will remove the ATS cover and look for obvious signs, i.e. discoloration of components, faulty connections, etc., etc.

Another tidbit of info that I just remembered. For the last few times we camped, when I plugged into the pedestal it would take longer than normal time before the Monitor Panel indicated 50A. And sometimes I would turn the pedestal CB off and on a couple times before it got power to the system. In reading this afternoon I found where it should only take 3-4 seconds for power after plugging into the pedestal, if the generator is not running.

I'll continue to read and discover. Also, I'll post any results here.

mikwallace · 01-28-2022, 07:47 AM

UPDATE:

I tried to upload a video of the ATS with the cover off, but I guess this forum won't upload .mov video files. The Shore Power Contractor is making a loud buzzing sound. With the cover installed and the basement door closed the buzz is barely noticeable. When the Generator Contractor is engaged it does not buzz. The failed condition I experienced has not happened again. But with the Shore Power Contactor making this noise, I fear its not far from failure. A quick search by google didn't come up with an identical replacement; will search further.

Anyone experienced this? Did you replace the contactor or the complete ATS?

Thanks!!

Updated Info:

Appears there's not any serviceable parts within the ATS. The only contactors I could find were 50Hz. A new ATS is now on-order and should arrive within 5 business days.

HarryStone · 01-28-2022, 09:00 AM

That buzzing shouldn't be normal. Sounds like you are on the way to a good fix.

mikwallace · 02-01-2022, 11:09 AM

UPDATE:

The transfer switch never malfunctioned again; however, the Shore Power Contact was “BUZZING/HUMMING” and the Generator Contact does not. Best I could find out is there’s not any replaceable parts inside the Transfer Switch. I did find a contact/relay but it was rated at 50 Hz not 60 Hz. I spoke with a Tech at United RV and he confirmed the “no replaceable parts” info. So, I ordered a new transfer switch; identical to mine, installed it. And no Buzzing/Humming!!!

I believe it’s checked off as “FIXED”! And a future malfunction averted!

Thanks for all the input.