Odd Electrical Issue (Converter Fuses)

[Dan_Frisbie]

My rig has the 25 amp reverse polarity fuses on the converter, 3 of them. Occasionally, for no reasonable or apparent reason, they will blow. I am not operating or working on anything.
I use a Bulldog power monitor and have very little running inside the rig (it’s in my yard).
Since it’s at home, I am in the MH once or twice a week and occasionally will find the batteries drained and when I do, the fuses are blown.
This has been happening since I bought the MH nearly two years ago.

Any ideas?

For the latest solution to keep from depleting my batteries, I have the battery switch “Off” and an external charger/maintainer on the batteries.

 

[GTS225]

Just speculation on my part, but maybe there's voltage spikes or drops happening on your grid that effects the fuses? (Yeah, I might be "reaching".) As an industrial electrician, (retired), I did very occasionally run into fuses that seemed to be rather sensitive to anything other than "clean" power. It might be worth asking someone knowledgeable in fuse construction.
Hmmmmm.....is it always the same fuse that's blown?

Just my brainstorm part.....Roger

 

[Kevin D Pem]

When you say occasionally, what does that mean?

Depending on what that means, I would have two ways to proceed. Short time duration, I would remove all the house 12v fuses (be sure you log fuse values). Considering normally short duration replace fuses one at a time till you have a failure! Then look for a short in equipment on that circuit.

Long duration problem!
Pull half the fuses, and wait. No failure! remove those fuses,and replace the fuses you had removed previously. When you get a failure. Remove half of remaining fuses, and repeat the above until you have isolated the bad circuit and hunt down the faulty equipment.

Keep in mind that wires can be compromised by staples or screws also.

Any other answers will come to you when you have isolated the circuit.

My first thought is, once a week visit, resulting in dead batteries, says you have a hefty load turned on. That is not normal with everything turned off! And the issue with the converter says we are talking 12 volt system.

 

[Wemustrv]

In addition to other posts take the time to check the wiring going to the fuses for loose connections. These are houses moving down the road and vibrations and bumps can cause loose wires. Loose connections causes resistance which in turn causes heat and heat can result in nuisance tripping of the thermal element of the circuit breaker or fuse.

 

[Dan_Frisbie]

Just speculation on my part, but maybe there's voltage spikes or drops happening on your grid that effects the fuses? (Yeah, I might be "reaching".) As an industrial electrician, (retired), I did very occasionally run into fuses that seemed to be rather sensitive to anything other than "clean" power. It might be worth asking someone knowledgeable in fuse construction.
Hmmmmm.....is it always the same fuse that's blown?

Just my brainstorm part.....Roger

All three fuses blow.

 

[Dan_Frisbie]

When you say occasionally, what does that mean?

Depending on what that means, I would have two ways to proceed. Short time duration, I would remove all the house 12v fuses (be sure you log fuse values). Considering normally short duration replace fuses one at a time till you have a failure! Then look for a short in equipment on that circuit.

Long duration problem!
Pull half the fuses, and wait. No failure! remove those fuses,and replace the fuses you had removed previously. When you get a failure. Remove half of remaining fuses, and repeat the above until you have isolated the bad circuit and hunt down the faulty equipment.

Keep in mind that wires can be compromised by staples or screws also.

Any other answers will come to you when you have isolated the circuit.

My first thought is, once a week visit, resulting in dead batteries, says you have a hefty load turned on. That is not normal with everything turned off! And the issue with the converter says we are talking 12 volt system.

Occasionally, as in there is no time, reason, circumstance, or any type pattern that I can discern.
It seems completely random.

 

[Kevin D Pem]

Occasionally, as in there is no time, reason, circumstance, or any type pattern that I can discern.
It seems completely random.

That is a problem, as time to troubleshoot will be extended. The positive side is you probably have a screw or staple causing the issue that may be found by wiggling wires around.

 

[GTS225]

All three fuses blow.

Now, THAT causes me to raise an eyebrow and start questioning the high voltage side of the inverter. I worked in 3-phase AC, and anytime I found all three supply fuses blown, I strongly suspected the load.....in this case your inverter. (My loads were motors more than anything else, but also VFD's.) If it were something on the low voltage side, I would think a low voltage fuse would pop, rather than your reverse polarity fuses.
But....."we" haven't ruled out something you may be doing, that you haven't realized is related to the issue. Try to think back to each time you've found blown fuses. Did you do something with your household power that may have influenced this? (Start an air compressor, plug in a high pressure washer, etc., etc.?) Unplug the RV, and maybe plug it back in? Did anything happen to the grid power that you can recall?
These are the type of questions I would ask machine operators, to try to give me better info when I did my troubleshooting.

Roger

 

[Kevin D Pem]

Now, THAT causes me to raise an eyebrow and start questioning the high voltage side of the inverter. I worked in 3-phase AC, and anytime I found all three supply fuses blown, I strongly suspected the load.....in this case your inverter. (My loads were motors more than anything else, but also VFD's.) If it were something on the low voltage side, I would think a low voltage fuse would pop, rather than your reverse polarity fuses.
But....."we" haven't ruled out something you may be doing, that you haven't realized is related to the issue. Try to think back to each time you've found blown fuses. Did you do something with your household power that may have influenced this? (Start an air compressor, plug in a high pressure washer, etc., etc.?) Unplug the RV, and maybe plug it back in? Did anything happen to the grid power that you can recall?
These are the type of questions I would ask machine operators, to try to give me better info when I did my troubleshooting.

Roger

He said converter.

 

[GTS225]

He said converter.

OOPS! Don't get old....the memory starts to slip, and body parts start failing.

Roger