Stupid Electrical Trick - A Reminder

[Thom]

Duh .....

Let's see, I put in a new transducer last week, and had the batterys out when I did that. Cleaned up some wireing and put it all back together. Everything was turned off of course.

Got a new speed/temp transducer yesterday and hooked it up to make sure it was working. Went back and flipped on the battery switch, then into the cabin to turn the breakers on. No indicator lights on the breaker panel didn't seem right, and I looked back towards the back of the boat. Smoke was billowing out of the transom hatches. Quickly flip the battery switch off and open the hatch.

Lesson 1: Do not breath that smoke. One battery terminal melted and several burned cables.

I removed wires in a hurry.

Lesson 2: Do not touch a wire that has just had its insulation melt, no matter how excited you are.

Now to figure out what was wrong.

Lesson 3: Mark the positive and negative terminals with white paint in big symbols in the future.

One battery was connected backwards. My mistake, no one else's. The batterys are marked by very small embossed + and - Symbols in the case, I had a hard time finding them to confirm my suspicion that I had put them on backwards. I think I may just take a can of red spray paint and shoot a blob of red paint onto the side of the battery that is Positive. That should be hard to miss in the future.

The moral to this story: pay attention.

Thom

[Nimrod]

Hey Thom, Can we laugh if we've been there before?

[HOTSPOT]

Thom,

I had a trolling motor harness do this to me last year under the front casting deck. I also grabbed the melted wire and got burned. My brand new fire extinguisher would not fire, my son threw me a bottle of water to put out the fire on top of the battery. It was a mess, scary as hell. The trolling motor circuit breaker failed and the wires overheated and melted together causing the whole thing. We had just used the trolling motor to get over a sand bar and were bragging on how good it was pulling us along.

I feel your pain, hope you did not get burned too bad.



Support THT and become a Captain's Club Member

HOT SPOT <'})))><<

Sea Pro SV2300 Yamaha F200
Ford F250 SD 4DR 4WD PowerStroke

[cfwegman]

Thats why we engineers call the first power-up of any electrical device after any wiring work "a smoke test"

Product Engineer, SMITH Marine Products, 21 Seacat, 2500HD Duramax/Allison

[BW23]

Thom,
It sure must be difficult to admit that you are taking advance education courses at Murphy's Law School. I've been there more than once.

Glad the damage was not more serious.

Now.....does a fuse/breaker protect the wire/cable or the equipment?

[Preoccupation]

Yup, Thom let the smoke out, it won't work anymore! Glad you're around to tell the tale...

BW23...a breaker or fuse is intended to protect the upstream wiring and system. A breaker or fuse is designed to open on abnormally high levels of current, not normal operating currents. Any device won't draw more current than normal operation unless something is wrong, like an internal malfunction or miswiring, etc. In any case the device itself is usually history, so the game is try to limit the damage to the upstream wiring and equipment...

[auguste]

Thom . . . glad you're OK

My neighbour is totally colour blind . . . his solution is what you did . . . he painted large + and - signs in white . . . he was unlucky in that his son lost two fingers in trying to pull burning wires from incorrectly connected cables (he didn't think of turning off the switch).

Again, glad you are OK !



. . . just thinking out loud . . . yes, I'm "Miss-Be-Haven"

"49.6 mph on a beautiful calm day . . . fully loaded . . . going down hill"

" The only boat without a ding or four, is the one that never gets used!!! "

[Think Tweiss]

I feel I can now come out of the closet....

I installed two new batteries early in the morning, started the boat and ran out to fish on battery 1. Pulling up to the reef, I decide to turn the battery switch to #2 for the return trip. I Turn the perco switch to BOTH on it's way to 2 and spark/smoke/engine dies..no power. Opened battery access and saw smoke. Pliers and cloth to remove wire from one battery very quickly.

Just in cellular range and sea tow to the rescue. Yup...put in one battery backwards. Must have welded the inside of the Perco switch and destroyed (internally) one of the new batteries.

Cost to fix was $30 and that included replacing the Perco, two links in the engine and a couple of other fuses. Battery was replaced under warrantee. (what me do something wrong...must have been a bad cell).

Scary as hell...still thinking about the explosion and fire that fortunately weren't...or if I went out another mile. (yup, now have lots more safety gear on board than I had when this happened).

Oh yes, I should tell you that I am an electrical engineer....

The views and/or opinions stated by the author in this post are the views and opinions of the author

[Birdman]

Oh...I've done ALOT dumber and stupider things than that!! That almost classifies as a smart thing that I've done.

Ever try putting your hand flat down on a red hot cast iron burner (for cooking), and wonder why it is slippery and feels "wet"? That slippery wet stuff your feeling oddly enough, is your hand melting right in front of your eyes!! And no, it doesn't hurt at all, I did not feel a thing, until about 10 seconds later at which time I'm pretty sure Thom herd me scream all the way up in the mountains 600 miles away even though he was still in the bilge of his boat trying to let the smoke clear.

Birdman, Capt of

Scout Abaco 280 Click here!

[gbutler]

Thom,
Glad your OK and dont feel too bad short story to add.
New boat.

Convinced wife we needed dual batteries for safety.

Not a problem worked for years as a mechanic simple install honey.

Mis connected 1 little wire.

Lots of smoke.

To this day she makes me take it to a shop for anything electrical.

Fortunatly was only a small harness easialy replacable.

Greg

[gerg]

OUCHHHHH!!!

Ok, so I trust you are ok and the big ducer still works? phew.

thanks for the reminder......

** yeahah **

[trouty]

You won't be the first or last to have to admit to human error Thom.

Even when we know how to fdo it we can still make mistakes.

So - what was your mind REALLY on while you were hooking up the battery terminal wrong?

Accidents happen usually when our minds somewhere else, you know - I nodded off at the wheel the other day, found myself half way into the oncomming lane, luckily no one comming the other way.

It's happened before, many years ago (strangely enough in almost the same place) when I needed glasses and didn't know it - turned out I was short sighted (myopic).

Maybe I need new glasses again?

Learning to heed the warning signs is half the battle.

Man can only do one thing at a time (like connecting batery terminals) andf your mind was somewhere else solving another problem (or solving a potential problem with say the transducer or some other part of the wiring circuit ahead of you) then - thats likely the cause.

They show a great TV advert here just lately for beer..guy in a crowded bar trying to remeber the order for his groups round of drinks..and muttering it to himslef over and over again.."a vodka and orange, two bundy and cokes and a scotch", "a vodka and orange, two bundy and cokes and a scotch" etc etc etc.

As the guy in front walks away from the crowded bar with his drinks, he fronts the bar and this drop dead gorgeous blond with big hooters in a white tee shirt with 'cougar beer' printed on it, beams him a big smile and says "what'll it be?" and the idiot with eyes out on stalks replies, "ahh, 5 beers thanks!!!"

Keeping the mind on the Job can be tough anytime, we are all human.Bet your still kickin yourself Thom. Don't be too hard on yourself.

Cheers!

[Mumblerone]

Thom...if this could happen to you; I'm paying more attention. Thanks for the reminder. I'm glad things worked out!

Boston Whaler, "MUMBLER", 24' Outrage, twin 175 HP Evinrude Ocean Pros. Snowball, the cat...