Electrical power question

westxsrt10

Perfict Senior Member
Headed out tomorrow for a short trip to Ute Lake NM and i'm checking things out to find: I have my shore power 120 ac connected and everything works, but when I disconnect my battery (disconnect switch) I have no 120ac power or 12 volt power. Basically nothing works with the AC plugged in and battery disconnected....is that normal?
 

SouthernNights

Past South Carolina Chapter Leader
I understand about the 12 v side not working when you shut off your battery. Sounds like the convertor is not working or not working properly.

I sure cant figure out why your 120 v would stop though.
 

2010augusta

Well-known member
Why are you disconnecting the batteries while using the trailer?

Maybe 120v transfer switch has some 12v component function.
 

newbie

Northern Virginia
There isn't any other power source to the transfer switch other than the 120/240 power source either from the gen set or shore power.

The 120v power is independent of the 12v lighting and the battery disconnect should have no effect on the 120 power.

Try checking a receptacle with a meter and see what it reads.

John
 

westxsrt10

Perfict Senior Member
Why are you disconnecting the batteries while using the trailer?

Maybe 120v transfer switch has some 12v component function.

The trailer is in my garage right now...i wanted to slow charge the batteries before we leave. I dont leave the unit plugged in while not in use as the factory builtin charger may overcharge. It could be the way i have the master battery cut-off switch wired? ( I have one leg of the switch bolted to the frame and the other leg connected to the neg. terminals of the batteries.)
 

dreamer

Member
I think you have tripped a breaker on your land power and that would explain both the lack of 120 volt and 12 volt when you do not have the battery in place.
I think your problem sounds to be in the wiring of the disconnect switch.I would wire it with one leg attached to the negative battery post and the other leg attached to the wire you took off the negative post. The way i understand you have it wired it is either doing nothing or causing a short.
Hope this helps
 

westxsrt10

Perfict Senior Member
I think you have tripped a breaker on your land power and that would explain both the lack of 120 volt and 12 volt when you do not have the battery in place.
I think your problem sounds to be in the wiring of the disconnect switch.I would wire it with one leg attached to the negative battery post and the other leg attached to the wire you took off the negative post. The way i understand you have it wired it is either doing nothing or causing a short.
Hope this helps

I checked all the breakers and none are tripped. Its weird that by disconnecting the neg. battery terminal shuts off the shore power. I havent really changed any wiring by having the cutoff switch in series with the battery ground. :confused:. The 120 ac works perfict with a battery in the system. Maybe all the units operate this way? We're leaving for 3 days in the morning so i'll dig deeper to find the answers next week.
 

SmokeyBare

Well-known member
I have discovered when I am at a Campground that has LOW AC power... my converter shuts down. When the converter shuts down the whole RV loses power.

First time this happened I was at a Gainsville Georgia County park... the electrician found one leg was about 109 Volts. We would start the FAN ONLY on the A/C... then switch on the COOL... which would kick in the A/C compressor... that was when the Converter would shut down.

It's happened only a few times but I've since bought (Yeah more accessories) a surge guard - Auto-Former to protect the electronics of our BigHorn.

Marv
 

KENNY COCHRAN

MCNEESE STATE COWBOYS #1
I don't leave the unit plugged in while not in use as the factory built in charger may overcharge.

I WOULD NOT WORRY ABOUT THAT. THEY ARE DESIGNED TO WORK 24 HOURS A DAY. I HAVE HAD MY RV'S PLUGGED IN FOR THE LAST 7 YEARS WITH NO PROBLEMS. I HAVE MORE PROBLEMS WITH HURRICANES BLOWING THE RV OFF OF MY LOT SO I HAVE TO MOVE IT WHEN THEY COME;)
 

Elevatorman

Active Member
I checked all the breakers and none are tripped. Its weird that by disconnecting the neg. battery terminal shuts off the shore power. I havent really changed any wiring by having the cutoff switch in series with the battery ground. :confused:. The 120 ac works perfict with a battery in the system. Maybe all the units operate this way? We're leaving for 3 days in the morning so i'll dig deeper to find the answers next week.

Do you think that by disconecting the ground side of the battery you might be opening the ground circuits for the 120vac also, or maybe ahead of the converter? You never know how they may have run the ground loops. To them a ground is a ground, they just tie them all together. All of them should end up to the chassis somewhere!
 

Chainsaw

Saskatchewan Chapter Leader
since this is the closest I could find on the transfer switch, has anyone has problems where the shore power does not work until after you run the gen set for a few minutes? I called CS at HL and was told to look at the switch. I did and I didn't see anything< don't know what to look for. Any ideas, has anyon ehad this problem?
thanks
 

Rickhansen

Well-known member
since this is the closest I could find on the transfer switch, has anyone has problems where the shore power does not work until after you run the gen set for a few minutes? I called CS at HL and was told to look at the switch. I did and I didn't see anything< don't know what to look for. Any ideas, has anyon ehad this problem?
thanks

I don't have a genset or transfer switch, but my Surge-Gard protector has a delay of about 90 seconds before it applies power to the coach. It is to prevent short cycling of the A/C's when power is restored. I'll bet your transfer switch is the same.
 

westxsrt10

Perfict Senior Member
This is a very old thread but my problem was the converter.....it went 100% out a few months later. I'm not sure why this happened but a new converter and removing the battery cut-off switch solved my issue. I think my converter was bad from day one as the lights always dimmed every few minutes.
 

newbie

Northern Virginia
The transfer switch by default should connect to shore power. When it see's generator power, after about a 30 second delay, the transfer switch will switch to generator power. Once the generator power is shut off, the switch will switch back to shore power. Also, if you are plugged into shore power, the transfer switch will still switch to generator power after it "sees" generator power.

If the generator power should drop below (about) 105 volts, the transfer switch will instantly drop generator power and switch back to shore power (if connected) or an open state if not connected to shore power, until the generator power goes above (about) 105 volts. This will happen if you try to restart an air conditioning unit on a hot day shortly after it has been shut off (the air conditioner has very high head pressure and requires a ton of amps to restart resulting in a big voltage drop)

Hope this helps,
John
 
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