Fuses, what fuses?

[safariuser]

[/IMG]My 85 sovereign has a fuse panel but instead of fuses I've got these little relay looking things? What are these and how do they work?

[safariuser]

[pmclemore]

Those are your 12-v self-resetting circuit breakers.

[safariuser]

Thanks! They must work as all the circuits are good. Now all I have to do is replace the converter that died yesterday.

[dbj216]

Converters are transformers. They "convert" 115v AC to 12v DC. I don't hear about them failing very often. When they do, it can be a smelly melt down of the coils. They are usually plugged into a regular 115v outlet that is protected with a standard 115v circuit breaker. There can be a fuse protecting the 12v output of the converter. My son's 69 Globe Trotter has a little fuse panel located behind a piece of tin on the converter itself. If you still have the original converter, you might look for a couple of sheet metal screws holding a metal cover. That may be why you are not getting any output from your converter. It's hard to blow a 20 amp 12v fuse. There may be a 12v wire touching a ground causing a high draw short. Maybe there is a 12v motor somewhere (furnace, vent fans, water pump) that is jammed from rotating and thus drawing a high load. And maybe the 12v battery is shot drawing a high current load trying to charge itself.

David

[safariuser]

Thanks for your reply rivet master. I checked, no fuse, batteries are new, motors are all turning. This thing hums but produces no juice. I'm going ahead with a replacement. Do you know anything about these self resetting circuit breakers?

[dbj216]

Hi safariuser. These circuit breakers are bimetal strips that open up when they get good and hot. They will re-close as they cool. I don't think they are as fast responding as a fuse or a 120v circuit breaker, but I really don't know. Here is a little description of the devices...

Automotive Circuit Breakers | WiringProducts

I test them like a do a fuse. If I have continuity with my ohm meter, then I assume the circuit breaker is good. You might verify that all the circuit breakers in your box are closed, not open, and have very little resistance across the posts.

A humming converter is a good sign. Mine hums away too. My converter had one heavy 12v wire to power all the trailer's 12v circuits, and one wire to charge the battery. So if you are plugged into shore power and your converter is humming away, I would expect to see something like 13.8 volts across the battery terminals. With the converter off, I would expect to see something like 12.8 volts across the battery terminals. This would be a sign the converter has a 12v output to the battery.

By the way, I assume all your 12v devices run when on battery power only. Airstream was one of the first to make all devices (lights, fans, water pump, etc) 12v. They called this "univolt". So your trailer worked the same plugged in or not. Your 12v system receives power from the battery OR converter. Everything down stream does not really know how its being powered.

Now you would need to test the main 12v supply wire out of the converter. Mine is red in color. Follow that wire along and see where it connects to your Safari's 12v system. Test the end of that wire to ground. I would expect to see about 13.8 volts on my meter. If no volts, then maybe the wire is disconnected somewhere.

It is possible to replace your converter and have the same problem! So I think its important you find the cause of no converter output.

By the way, welcome to AirForums. I have found all sorts of people who have helped me with my questions. And I have found there are no silly questions. Responses are helpful and informative.

A "rivet master" is a AirForums user that has made something like a 100 posts. I see you have earned one rivet already. Soon you will be a rivet master too, and that plus a dollar will get you a cup of coffee!

David

[pmclemore]

Is there a chance that you have a switch (mine is on the streetside wall next to the couch) that turns your converter on and off?

Pat

[safariuser]

My switch shuts off the power to the trailer while allowing the batteries to be charged. The converter charger is on if I'm plugged into shore power. Since I've now replaced the converter charger I have 13 or so volts feeding the trailer and the batteries. Thanks DBJ for the information on the self resetting circuit breakers. That's now a solved mystery for me!

Here is the information on my new converter charger.
PM3-55 POWERMAX PM3-55 12 VOLT DC 55 AMP POWER CONVERTER CHARGER WITH 3 STAGE AUTOMATIC SMART BATTERY CHARGING

• 55 AMPS DC OUTPUT
• INPUT VOLTAGE: 105 - 130 VAC
• MAXIMUM CONTINUOUS POWER OUTPUT 780 WATTS
• ALL POWER MAX CONVERTERS ARE AUTOMATIC THREE STAGE SWITCHING POWER SUPPLIES, THE CONVERTER SENSES WHICH MODE IT NEEDS TO BE IN BY CHECKING THE RV SYSTEM VOLTAGE
• WEEKLY EQUALIZATION FOR LONGER LIFE: IF THE POWERMAX VOLTAGE REMAINS IN THE LONGTERM STAGE FOR MORE THAN 7 DAYS THE SMART TECHNOLOGY WILL AUTOMATICALLY DELIVER A BOOST CHARGE FOR A PREDETERMINED TIME THEN AUTOMATICALLY RETURN TO THE NORMAL FLOAT STAGE
• REVERSE BATTERY PROTECTION: THIS FEATURE PREVENTS PERMANENT DAMAGE TO THE CONVERTER FROM AN INCORRECT BATTERY CONNECTION
• ELECTRONIC CURRENT LIMITING: AUTOMATICALLY SHUTS DOWN POWER DURING OVERLOAD OR SHORT-CIRCUIT CONDITIONS AND RETURNS TO NORMAL OPERATION AFTER CONDITIONS ARE CORRECTED
• 3 STAGE CHARGING: ABSORPTION MODE, BULK MODE AND FLOAT MODE
• AUTOMATIC COOLING FAN: THE FAN IS VARIABLE SPEED AND CURRENT CONTROLLED
• OUTPUT VOLTAGE RANGE:13.6V - 14.4V DC
• OUTPUT VOLTAGE TOLERANCE - NO LOAD - + OR - 7%
• OUTPUT AMPERAGE, MAX CONTINUOUS: 55 AMPS
• INPUT VOLTAGE RANGE: 105 - 135 AC
• INPUT VOLTAGE FREQUENCY: 47 - 63 Hz
• MAXIMUM AC CURRENT @ 108VAC : 10 AMPS
• TYPICAL EFFICIENCY: 85%
• MAX INRUSH CURRENT, SINGLE CYCLE: 40 AMPS
• SHORT CIRCUIT PROTECTION
• OVERLOAD PROTECTION: >100%
• LINE REGULATION: 100mV ms
• LOAD REGULATION <1.0%
• THERMAL PROTECTION
• WORKING TEMPERATURE RANGE: 0 - 45C
• STORAGE TEMPERATURE -20 TO 80C
• WITHSTAND VOLTAGE: 120V @ LEADS
• UL LISTED AND cUL LISTED
• FCC COMPLIANCE CLASS B WHICH MEANS THE CONVERTERS ARE DESIGNED NOT TO CAUSE INTERFERENCE WITH TELEVISIONS, RADIOS OR OTHER SIGNALS
• DIMENSIONS: 8W X 3.6H X 9D
• WEIGHT: 8 LBS
• 2 YEAR WARRANTY