12 Volt Trips Then Comes Back On.

[tbashin]

I recently purchased a 1976 31' "Canadian wired" Excella 500. Last week I installed a full propane tank and got my heater up and running. I also got the stove/oven working as well. Now it seems when either are on, the converter starts to trip intermittently but it resets itself within a few seconds.
Am I correct in assuming I have a overheating issue with the converter? Looking through the side access panel I found a 120 Volt fan and a 120 outlet in a blue box store outlet box just inside this access panel above the 12 Volt fuse panel. You have to reach into that area to plug the fan in. It has no switch.
It is not the original converter but I can't see the brand or model through this side access. It's behind the stove by the way.
Is that fan original maybe? Am I correct in assuming I have an overheating converter? It is tripping inadvertently, not every time I light the heat sources near it.

[A W Warn]

It might not be the converter.
Sounds to me like a self resetting 12 volt breaker/fuse. Overload or short will heat them causing the circuit to open. When they cool, they reset. Sometimes they just fail and need to be replaced.

Look for something like this >>
https://www.delcity.net/store/12V-Au...iABEgIjDvD_BwE

These are available at almost any automotive parts store.

There are several in the 12 volt electrical box behind the sofa in both of my trailers. There are also a couple in the area around the converter that are mounted to the floor and/or wall.

Has your trailer been re-wired?

[tbashin]

I will look for that type of self resetting fuse. Our trailer is 99% all original and has not been rewired. The converter seems to be the only new device in the electrical system before we got it. I did install a new radio and door bell and door bell button. The radio is next to the door. There is a 12 Volt terminal block mounted to this entertainment cabinet fed by heavy gauge red and white 12V wire. The door bell, radio, and exterior flood light are fed from this block. There is an inline 12V fuse on the heavy hot wire but it’s a standard glass auto fuse, not a self resetting one. It’s strange because it has sat on shore power continuously for about 5 months without tripping.

[HowieE]

You have 2 completely different electrical systems in your trailer. 120 volt AC that feeds the convertor, the 120 volt side of the frig, and any other 120 volt receptacles. A 12volt DC system powered by the batteries that feeds the lights, control for the heater, control for the frig, water pump, and the monitoring panel if equipped.

Sounds like you are describing a 12 volt circuit. My first thought would be to check the batteries since they were plugged in for so long. If your convertor does not have a battery monitor function they may be cooked and you are tripping a 12 volt circuit breaker.

The convertor requires fan cooling and should be plugged in when ever on shore power. The fan should be cycled by a thermal switch in the convertor itself and come on as needed.

[tbashin]

I do not have a battery installed. This model had only one battery and it was toast when I got the TT so I have been running strictly on shore power. It's definitely only the 12V system. I'll put a fresh battery in once I get ready to start camping; still cleaning and fixing finishes (and chasing a 12V trip) for now.
Since it was a Canadian model, the 120 V Breaker box is in the closet on the road side. Also in the closet are two 12 volt wire sets which are wire nutted off. I have no idea what they are supposed to feed. Any ideas on those?

[Boxite]

Oh, come ON! You are there looking at 'em and can't tell what they are for... but you expect us to read your words and decipher it for you?

It sounds like you need to get someone qualified (like an electrician) to help you with this.. but I'll tell you this....
... a battery should be in your circuit because a battery does more than power things directly/alone. A battery in the circuit also behaves like the huge capacitor it really is... In other words...a battery acts like an electrical "shock absorber" and will level-out surges, overloads, etc etc.

I truly advise you to get someone qualified on-scene to help you with this one.

[A W Warn]

Originally Posted by tbashin

I do not have a battery installed. This model had only one battery and it was toast when I got the TT so I have been running strictly on shore power. It's definitely only the 12V system. I'll put a fresh battery in once I get ready to start camping; still cleaning and fixing finishes (and chasing a 12V trip) for now.
Since it was a Canadian model, the 120 V Breaker box is in the closet on the road side. Also in the closet are two 12 volt wire sets which are wire nutted off. I have no idea what they are supposed to feed. Any ideas on those?

The 120v breaker box in the closet is not unusual. I owned a mid 70's US trailer that had the breaker box located there.

The original converter did require the battery as stated above. However, depending on which converter was used as a replacement, the battery might not be a requirement. For the two converters I installed in my trailers in the last few years, the instructions said specifically a battery is not required for proper operation. Check the manual for your converter to be sure. That could be contributing to your problems.

In the mid 70's model trailers there was some type of sway control system that was offered as an option. I do not know how it operated or were the components were located. Could it be those two wires might be for powering that option? Or, those wires could have been added, not original. Photos would help.

The sway control option is shown on page 79 in the manual for your trailer. This is a link where you can download it.
https://www.airstream.com/wp-content...xcella-500.pdf

The wiring diagrams in the manual should help you sort out where the wires go.

[CBWELL]

As per the Airstream shop manual, the sway control is to be mounted on the floor, below the front lounge. Color of wires are: White, off the shunt. Blue, off the brake line (12volt). Black, off the breaker (12volt). White is ground, Blue controls the synchronizing valve for brakes, and Black is power. I suspect that the wire in the closet is something a PO installed. Track it to the source. The only difference in a "Canadian" 120 volt wiring is the location of the 120 volt panel. Different code for distance from water closet and sinks. Possibly different line amp requirements, and grounding. Nothing major. You will probably do damage to the converter if you don't have a battery installed. Suggest that you install ASAP.

[tbashin]

Hey Mr. Boxite. Your comments are unwarranted. FYI: I consider myself pretty good at wiring, electrical, carpentry, plumbing, safety, etc. In my 62 years, I've wired street rods, import cars, tractors, my house, my barn, my shop, my other RV, HVAC controls in 60 story buildings, and much more. I am also a pipefitter, welder, and a licensed plumber by trade. I work for a "LARGEST" Mechanical Contracting company in the USA. Yes I know HVAC too. I say that to say that I consider myself pretty good at figuring out stuff without getting into trouble so hold the wise cracks because here in Texas where I was born and raised, we are taught that if you can't say anything good then don't say anything at all. Especially if you don't know all the facts.

Now for those willing to offer helpful comments, I do have the original 1976 Excella owner's manual, & the 1976 Excella Service Manual which shows MOST of the wiring, (not the 12V in the closet however).

AND... I found the original manual last night for the Converter in between the stove and the wall by the access panel. It had the receipt in it too dated 5/29/2009 from Best RV & Truck Supply in Boise, ID. It is a Xantrex XADC-60. Nowhere in the manual does it say whether a battery has to be installed or not. Advice requested if you know the facts here!
I also found none of the self resetting fuses in the trailer (have not removed the couch, cabinets, stove, etc. to look there). I'll look more tonight again. Here are a couple of pictures, the 12V wiring from the Service Manual, and the 12V mystery wire (it's not for the closet lights those come out of the ceiling through a grommet).
If anyone else has any ideas on why the converter shuts down then comes back on, let me know.
If anyone else has seen a 12V accessory or device in the closet of a 1976 Excella 500 center bath let me know too.

[Al and Missy]

In your third photo it looks like the wires might be interfering with the fan. Just for good practice they should be tie-wrapped out of the way. Assuming that is the AC powered fan you mentioned, if you plug it in does the problem go away? The furnace draws a significant amount of 12V current, the stove does not.

I changed the converter in my 2001 Safari. There were air vents in the cabinet it was mounted in that were configured for the original converter. I wasn't sure the new one would get enough air flow but it did. Check to make sure that the in and out air vents on your new converter are not obstructed by the way it is mounted.

I looked at the installation manual for the unit. I'm not a fan of the thermal design. The cooling air input and output are adjacent to each other on the panel. If mounted in a closed box the unit will be ingesting its own heated exhaust air for cooling. Over time the temperature may be building up and tripping a thermal cutout. If the input and output are not separated somehow, you might try building some ducting to pull intake air from the cabin area separate from the exhaust.

Al

[tbashin]

Al, Thanks for the input. I have not tried the AC fan, yet, because I would rather isolate if I am having an overheating problem with the converter first. I do know that the converter's fan is working. Whether the converter fan t-stat sensor that calls for "ON/OFF" cycling is working properly is yet to be determined. The converter fan does cycle itself on and off and it does so even when the heater and oven are on. By it turning its fan off while those heat sources are on, tells me that the fan is satisfied with the temp inside the converter according to its t-stat.

[Boxite]

Originally Posted by tbashin

Hey Mr. Boxite. Your comments are unwarranted. FYI: I consider myself pretty good at wiring, electrical, ...I say that to say that I consider myself pretty good at figuring out stuff without getting into trouble so hold the wise cracks because here in Texas where I was born and raised, we are taught that if you can't say anything good then don't say anything at all. Especially if you don't know all the facts. ...

I didn't mean anything disrespectful... I wrote what I did because YOU wrote:

Originally Posted by tbashin

....Also in the closet are two 12 volt wire sets which are wire nutted off. I have no idea what they are supposed to feed. Any ideas on those?

Think about how that appeared to reflect upon your experience-level...

My advice (based on the scant info about "two wires" "nutted off" "any ideas?") was offered in good faith. Cheers.

PS: I'm also very familiar with Chappell Hill, as well as your local law who once christened me with my first traffic citation waay back in 1966 when I was 18 and "testing" my brothers GTO. (He had the desired-effect on me, as I always still fondly remember that when I drive thru every so often.)

[CBWELL]

Do you have a thermostat on the outside of the closet wall that faces into the bedroom? In my 1976 there was a furnace thermostat above the night table that was against the closet wall. The wires ran through the closet very similar to yours.

[TG Twinkie]

Sounds to me like your converter is "crowbaring".
Shutting down due to an overload.
The converter may be faulty.
I would start by removing the loads one at a time. Checking to see if the problem goes away. If the power stays on, reconnect that load and move on to the next.
What is the Ampere rating of your converter?
Is it located where there is adequate ventilation?

[rmkrum]

Crowbarring usually happens when a protective circuit in a power supply shuts it dow in case of overly high voltage from some failure. The crowbar circuits typically do not let the output Ho back to normal unless the supply’s AC input is turned off completely or a reset button is pushed.

That said, the problem might be that that particular converter needs a battery connected to its output in order to function correctly...

[tbashin]

Thanks for all the input folks. I have a few other items to try now. I do have a t-stat in the bedroom and its wired and working great. Those mystery 12 V wires are coming out of the road side wall about 5' off the floor. They are not shown on any of the repair manual diagrams I have for this year and model. Nothing shown in the original owners manual either. Also the gray and black tank sensor wires are also coming out of the wall down low and they are not connected. I need to get into the access pan at the tanks to see which end it just laying on the floor there in the closet.