Electrical Fireworks

[Lin]

After many months of no use, we have finally gotten away and are camping in the Mojave National Preserve.  It's quite nice except for the weather turning cold.  It was down in the 40's all day today!  Anyway, I was sitting quietly minding my own business when a heard a weird buzzing sound that seemed like it was coming from the radio speaker above the driver's seat behind my back.  I noted it, and went on with my activities.  A few minutes later, it happened again.  This time though, I noticed a flash of light by one of the kitchen counters.  As a looked, a little surge protector that was plugged in there burst into flames.  Fortunately, the flames died before I got to it and it just continued to smolder.  I was able to quickly pry the surge protector from the outlet with a handy spatula.  

I don't know why the breaker didn't pop if things were getting that bad, but I must say I am a bit uncomfortable with leaving anything plugged in when going to sleep tonight.  The only thing plugged into the surge protector was a cell phone charger without the phone even connected.  The charger seems to be fine, so I do not think I can blame it.  However, I will definitely unplug that when I am not around!

[Iceni John]

Do you have a true sine wave inverter, or a "modified sine wave" one?   I'm wondering if the power going into the surge protector has anything to do with the fireworks.   Maybe it's just the Made In China effect rearing its ugly head?

John

[Lin]

It's modified sine wave.  I didn't think of that possibility, but who knows.  I guess I will take it apart when I get a chance and see if there is anything noticeable , but I have my doubts about finding anything conclusive.  The thing has been plugged into the same outlet for years.

My wife has not totally freaked out about it but has presented the rhetorical question, "What would have happened if I had been out for a walk."  I was going to comfort her with saying the dog would have gotten it, but I knew she would have countered by saying the dog would be walking with me. I could have then suggested that it would be safer for her to walk the dog from now on, but that might have been counter productive!

[wg4t50]

Lin,
Agree, could been a bad situation, I have never had such an experience YET, and why I installed a Progressive Industries unit, they are from North Carolina, it is a 50 amp unit, that keeps look out for voltage range of 108 to 132 VAC, and frequency of 57-63, anything out of those ranges, it disconnects from what ever it is gtting power from, Generator Or the Pole. So now I have removed all the small units that were standard in my coach.
The unit I installed is the wired in 50 Amp model with the remote display, tells incoming voltage, Amps per leg and frequency of what is connected to, Pole or Genset. Listed at $309, but you can find them for less.
Cheers
Dave M

http://tweetys.com/electrical-management-system-hardwire-50.aspx

http://tweetys.com/progressive-industries-surge-protectors.aspx

[Nick Badame Refrig/ACC]

Hi Lin,

Once in a while, I get a brief loud buzz out of my dash radio speakers but

only while I'm driving.. I'm thinking that there is some kind of loose connection

that I have to track down. Now that some have said it could be inverter related,

I will have to further investigate.

Nick-

[Dave5Cs]

Lin what else is on that same circuit. You might check to see if anymore plugs or what ever is there also. Check wires in that plug too where the strip was plugged in.

Dave5Cs from Galaxy S III

[Lin]

Hopefully, the picture of the surge protector loads.  Notice the left outlet is the most burnt, but the two others show soot also.  I am not even sure which one the adaptor was plugged into, but I think it was the middle one.

Nick-- I do not think it was the invertor in this case.  My guess is that the shorting of the device itself sent out enough electrical noise for the speaker to pick up.  I also do not know why the breaker didn't throw.  Maybe I should change it.

[Seangie]

Lin - is that the outlet in the wall?

I had an issue with electrical this past fall.  I had a 20amp circuit (20 amp breaker) and was only using 2 x 15 amp rated outlets on the circuit.  It seems that having the heater hooked up to the same outlet with the microwave running at the same time was just enough to pull more than 15 amps but not enough to pop the 20 amp breaker.

Well over time the plastic on the 15 amp outlet got warm enough and eventually I started hearing a crackle and seeing a flash when I plugged something in.  Took it apart and it was looking a little toasty.  Like burnt marshmallow.   Now I am starting to just use 20 amp rated outlets for everything.

Might be something worth checking into.

-Sean


Fulltiming somewhere in the USA
1984 Eagle 10S
www.herdofturtles.org

[oltrunt]

Wow!  Looks like you got really close to a real big fire!  Glad you caught it in time.  Your comment about the breaker not blowing got me to thinking.  I've rewired a good number of automotive electrical burns and by far the most common cause was a bad connection--be it a loose ground, corroded connectors or poor contact where something plugs in (like a headlamp)  None of these will blow a fuse or trip a circuit breaker as they don't over draw amps until after they start a fire.  A "high resistance short" occurs and generates heat and melts the insulation from the wires.  Only then does a short occur and a breaker pop.  Generally by this time the vehicle is fully ablaze.  Its sort of like a kitchen toaster.  Its hot enough to start a fire but not drawing enough power to trip the breaker.  Without actually seeing your rig I'd have to suspect the problem to have been the zip strip itself and a poor bite on whatever was plugged into it.  I'll be interested to know what you finally come up with.

[Lin]

Sean- that's the plug-in surge protector.

Oltrunt -  thanks for the info.  It makes sense.

[jbnewman]

You might consider an arc-fault circuit interrupt (AFCI) breaker as part of an upgrade.