A/C and Fridge not working on shore power

[rsqfyrmedic]

Howdy all...hoping for some help. MH in question is a 1998 Damon Ultrasport 3670. Completely renovated with a new liquid roof, interior, laminate flooring, upholstery etc. Batteries all less than a year old. Replaced the power converter about 6 months ago. We just got back from a trip 3 weeks ago and everything worked peachy. I was going to prep for an upcoming trip and found all my batteries dead. Refrigerator and A/C don't work on shore power but the 110v outlets are. (Weird, no?) Everything works fine with generator power. (Once I charged the batteries.) The transfer switch is putting out 110v but I'm not getting any 110 voltage at the power converter. I didn't have time to pull out the converter but that's my next move...any suggestions?

[enblethen]

By chance did you have main engine running?
What make and model of genset? Is it possible it has a generator/starter?

[rsqfyrmedic]

I feel ridonkulously stoopid. Thanks for all the tips. I took everything apart and hit everything with the voltmeter. Shore power-122v in and out of the relay in the transfer switch (PD52) Same thing with the generator side, 120v in and out Took the converter out then noticed I missed 2 burnt fuses on the converter. Specifically, the main (30 amp) fuses on the DC distribution panel. Now my question is, why did everything work while on the generator? Thanks again everyone.

[Sam_Spade]

rsqfyrmedic wrote:
Breakers (in the house as well as the MH) good and I'm plugged directly into the 50 amp I've been using...no adapters, GFCI's are all good.

Sounds to me like there is some assuming going on there.....and that usually is a BIG mistake.

You need a meter to check the voltage one step at a time, starting at the 50 amp outlet that you are plugging into. Things fail, including wire connections and circuit breakers.

[doxiemom11]

We had 1 leg stop working on the power supply at the post in a campground and we also lost 1 leg of 110 when that happened. Check the power source too. Surprisingly it was ants nests in the circuit breaker on the 50 amp power box. Pulled circuit breaker, treated for ants, let treatment dry, installed new circuit breaker and all was good.

[MrWizard]

everything works on generator

some stuff does not work on shore power

you have either a bad shore cord
or a bad transfer switch

i know you say there is 110 at the TS, but there is a mistake in your diagnostics

you don't have a complete circuit supplying power thru the switch to the RV house breaker box, most likely one bad hot wire or contact
broken loose terminal in the transfer switch or shore cord

[wrgrs50s]

I would start with your transfer switch. It sounds like you are loosing one leg of power from the 50 amp output, therefore one leg is not powering your converter and other appliances, plugs, etc that are on that leg. The legs are usually labeled as L1 and L2.

Open up the cover of the transfer switch and first check for anything that may look burnt, or any loose connections with all power disconnected. Then connect to power and check for power on L1, then L2 on the output side while on shore power. Then switch to the generator and do the same check. I would bet that the contactors are losing one leg of power when on shore power only.

The refrigerator and furnace require 12 volts from your batteries to operate the circuit boards so that is one reason for them to not work if your batteries are dead.

[stickdog]

Had a fellow volunteer lose power to half his bus. It was the transfer switch. I helped him replace it he was an older guy so he was the brains and I was just labor.

[enblethen]

Look in transfer switch box for a control fuse.

[drsteve]

Batteries were dead, was the rig plugged in? If so I would suspect no power from the converter.

[time2roll]

rsqfyrmedic wrote:
I tested all the breakers and fuses...working fine on the genset but dead on shore power. There is power at the transfer switch so I don't think it's the twist lock plug. I'm thinking it might be the converter itself is dead but why would everything work on the generator?

Thermostat needs solid 12vdc on both the fridge and air.

Do the lights and water pump work?

Do you have a battery switch in the off or storage position?

What is the battery voltage?

Probably need a new transfer switch too.

[enblethen]

Bad transfer switch. Portion feeding from shore power.
Locate make and model, then post. if it is a dual relay system see if the relay pulls in for shore power.
Turn off power to rig. Check for continuity on the coils of transfer switch relays.

[ksg5000]

You tried firing up the generator and see if that changes anything? Seems to me that bad converter or bad transfer switch would be things to investigate.

[rsqfyrmedic]

I tested all the breakers and fuses...working fine on the genset but dead on shore power. There is power at the transfer switch so I don't think it's the twist lock plug. I'm thinking it might be the converter itself is dead but why would everything work on the generator?

[enblethen]

I would now start by:
1) turn off all breakers in rig, applying light pressure toward off.
2) Locate breaker for receptacle, turn it off applying light pressure toward off. Turn breaker on.
3) turn on main breaker in rig, followed buy branch breakers.
If this doesn't work, test the cable to the rig. Does it have a twist lock connector ate rig? If it does check for power there.
Do you have an energy management system? What does it say?