electrical question

[Tractorat]

This doesnt make sense to me. My power converter buzzes. I notice that if I turn off just the ckt breaker for the left side a/c outlets, the buzz goes away. At the same time, the 12 volt lights dim, and I see about a half volt dc drop at the voltmeter I have plugged into a cigaret lighter outlet in the trailer. Right side outlets still have power. Turn the breaker back on and the lights come up full and the voltage comes back up.

Does the main breaker protect the converter from amp spikes from shore power ? And the separate breaker that protects the left side a/c outlets also protect the trailer wiring from the converter ? That wouldnt make sense to me because the right side outlets still work. But my theory is that the converter, in addition to not powering the left side outlets, is now not charging the batteries.

 

[Bill Stockard]

Your converter produces about 13.6 to 14.6 volts when it is running charging your battery(ies). Your 12-volt lights dim when you turn the converter off because the lights are on battery power only which is around 12.2 to 12.6 volts at best. The approximate voltage drop is evident in the 12-volt bulb filaments. What you are seeing is normal.

The circuit breaker is for over current protection and not a surge protector.

Bill

 

[Tractorat]

Thats the thing. I dont think Im turning the converter off. The other ckt stays hot. Theoretically, this breaker should just be turning off the left side outlets.

 

[SnoKing]

If the lights dim, then the converter is turning off. It may just get its AC power from one of the house circuits and not be on its own breaker. Sounds like a 1990's trailer? SNOKING

 

[Tractorat]

Its a 1988. That must be it then. Thats what I thought it might be, but I just didnt believe it.

 

[Tractorat]

Interesting that it would have a main breaker as well as a breaker that shuts off the converter. BTW, the main breaker shuts everything off.

 

[SnoKing]

BTW, the main breaker shuts everything off.

As it should!!!!!!

Snoking

 

[Tractorat]

Then I guess the main breaker breaks the ckt from the house as well as the converter.

 

[Tractorat]

The breakers are not even close to being labeled correctly. Here is what Ive been able to figure out.

1. Left side outlets, includes refrig and converter.

2. Right side outlets only

3. Unused as far as I can tell

4. A/C only

5. Main Turns everything off. Even ckts that appear to bypass the converter.

The main bkr is 30 amp. The remaining 4 are all 20 amp.

The reason Im going thru this exercise is because I want to replace the converter to eliminate the buzz that the old converter makes. Im trying to spec out the new converter and I dont think the kid at the RV place is very knowledgeable.

So, with the above in mind, how many amps do I need on the new converter ? (the trailer is 30amp shore power service). And do I need to know the dc amperage ? (DC is protected by fusses)

 

[SnoKing]

You seem confused on what a converter is and what it does!

It is just a battery charger that turns AC into DC to charge the trailers batteries. The one minor difference is that most will power the 12V items with or without the battery in the system. It has no AC pass through capabilities.

It would be normal for it to have one of the 20 amp circuit breakers powering it. However as I said earlier it could be plugged into one of the two or three 20 amp house circuits that power outlets and AC lighting.

SNOKING

 

[Tractorat]

You seem confused on what a converter is and what it does!

Yes. But Ive got it figured out now. What confused me was looking at some converters on web pages. Im ok now, thanks.

 

[Bill Stockard]

A 45-amp converter at 12-volts is 540 watts. Changing 540 watts to 120-volts is 4.5 amps (If my math is correct). Presuming 100% converter efficiency, which it isn't, with the converter producing a full 45-amps output will require 4.5 amps at 120 volts. A 45-amp converter will probably draw around 5-amps at 120-volts at full output.

Bill