12v Systems Check

[sixkilo]

Blew a converter on Class C due to unit failure itself, or improperly wired 30 amp outlet(ie; dual pole breaker = 240 instead of single pole 120). Or at this point unknown overload? Hooked up to newly installed 30 amp RV outlet and tripped both coach and house side breaker. Reset each and had a thump come from Converter location with another tripped scenario. Plugged in generator and had both pop and smoke from converter. . New converter on the way but how do I check 12v furnace ignition, refrigerator ignition, water heater ignition? AC runs off generator. Any thoughts? Thanks.

[Rambeau]

While you are waiting for the new converter to arrive go buy a Progressive Industries Portable RV Surge Protector. I know not what you you asked but if you had had one it probably would have saved your coach. Check part of system you asked about by disconnecting the main 12V output from the converter and hooking directly to a 12v battery.

[Skip426]

It would be nice to know if plugging into a 240 volt wired 30 amp outlet was the cause of the failure , because many of the RV systems could have been damaged by the power surge.

Is your roof A/C controlled from the same t'stat as the furnace ?
If the t'stat , won't control the furnace , and you've checked all the 12 volt fuses, then damage to the furnace control board is also possible.
Does the fridge control panel light up ? LED's on ?
Do any of the RV's interior 12 volt systems work ? Lights ?

[sixkilo]

Yes I did that last night. PGD is sending new unit as well. Furnace cycles but does not light and same for water heater. Refrig sans ignition and shows failure code. 12v lighting works. Water pump works.

[sixkilo]

Yes Skip, the thermostat controls both. I am home now but do not know how to proceed with converter disconnected. I am sure I should not go to shore power , right?

[Jon_C]

I second purchasing the progressive Protector., i just installed the 50a permanent mount unit. If everything on yours was working fine before and it sparked when plugging in to shore power your inverter / transfer switch could be fried. Whatever your cord is connected to inside should have taken the brunt of the damage and may need to be replaced. Pulling covers and burnt smell should be an easy way to confirm what is bad.

I did have an issue where the hot and neutral was reversed on 30a pedistal and it sparked and tripped the breaker when i plugged it in. In that case the hot was connected directly to ground by the cable and didnt cause any damage thanks to the breaker trip. I just corrected the pedistal wiring and all was good. ( this was at a friends house not campground) so maybe youll get lucky too.

[sixkilo]

After talking to ProDym and Winnebago I am still not sure how the 110v and 12v systems talk to each other. So after ohms testing water heater control board for function via youtube demo( result was good) still with no ignition. I decided once again to set wall thermostat to gas only and waited for ignition. It did not fire but nonetheless the refrigerator started a low growl hum. The refer breaker was off as well as panel mode. The converter is gone as well. Furnace cycled and stopped as well as refer hum

[Jon_C]

In my experience the 12v and 110v Systems do not talk to each other they are isolated.
You have battery 12v that gets charged from either a device that is powered from 110v or your alternator when your engine is running or a generator. If you have a generator you probably also have a transfer switch which automatically switches from shore power to the generator after a short delay. The generator then powers the 110v charging device to charge your battery.
The device that charges the 12v batteries from 110vac provides a lot of isolation between the systems which is what you want in cases like yours, that is why your 12v system is still functioning normally after experiencing bad wiring on the 110v side. If something is bad on your coach its most probably the 110v charging device or your transfer switch. Best i can tell from the symptoms you describe.

[Jon_C]

And im thinking maybe your batteries are very low due to not being charged thats causing your heater and refer issues Have you checked battery voltage?

[sixkilo]

Isn't the converter an interface between the 12v--110v? I checked voltage on house batts and they are fine.

[F76Marion]

Sixkilo,

What exactly does "They are fine." mean as a number and underload??

I have cleaned up after this a few times now, and have more that that in fully toasted converters. It could happen, but I have very rarely seen damage to the 12V house electrics for these events. When there was, it was a really old converter that should have been replaced.

Things like the heat, reefer and maybe the waterheater that are "on" all the time may have taken damage to the control boards, but most of those have input fuses and other protections.

Frank

[Jon_C]

Originally Posted by sixkilo

Isn't the converter an interface between the 12v--110v? I checked voltage on house batts and they are fine.

Yes it is. Heres battery voltage vs state of charge table.

[sixkilo]

The mystery of no spark at lp appliances was solved once the new converter was installed. I had stopped to fill up propane and the service person turned off service to coach but failed to turn it back on at finish. At my destination plugging in tripped circuit breaker for both converter and microwave. Focus went to the electrics and lp service forgotten. As of now the microwave is toast so something did go down on that shared circuit. What generally fails on a microwave? Box of chocolates indeed!!!

[Dennis4809]

Originally Posted by sixkilo

Isn't the converter an interface between the 12v--110v? I checked voltage on house batts and they are fine.

When you see “converter”, think battery charger.