The Wrong Components

Cariboocoot

Having just woken up from one of my utter-lack-of-power naps I reviewed several threads and notice an odd coincidence: every one of them mentioned some inappropriate use of one component or another, and often with not-at-all hilarious consequences.

From switching out breakers to picking the wrong batteries to expecting AC controls to handle DC it's all been done, and never are the results what the user intended.

So go ahead guys: tell us your tales of "You won't believe what they were using for this!"

South Africa

Re: The Wrong Components

There where a few times I was dumber than a rock, more stupid than soil. :-)

Whilst re-configuring batteries, with careful concentration, double checking everything, I started by connecting the pos and neg on 2 batteries. (24v).

A bunch of friends for the kids arrive. When I got back to the job on hand, started where I left off ... by connected the pos and neg of the batteries.

The moment I saw that last wire becoming drops of molten metal, with the droplets starting to melt into the casing, all I could think of if this explodes now ... :-)

Apparently it was a sight to see me lifting off straight into the air. (was standing legs spread over the batteries.)

Good thing I kept hold of the connecting cable. Thanks to it melting, with me taking off, I took it with me, breaking the circle of death. :-)

One battery was done there and then, the other failed a few months later.


Another time I got this brainwave! Why not connect the 150w inverter direct to the charge controllers output. I mean, it made sense if you want to use the power on / off feature based on current from the panels! And the wires, they fitted. :-)

One (cheap) controller had the smoke leave it, and we all know that without the smoke kept inside electronic equipment, it does not work.


Last one.
Another time I carefully made all the wires neater, trying to make it look professionally done. Right at the end I discovered that I forgot the battery temp wires coming over the shelf instead of through it.

No problem. I mean, all I have to do is disconnect them inside the controller and pull them out. Simple.

Mistake!

As I pulled them out, they touched. They became an instant heater element. The smoke from the insulation burning was like a whiteout. Grabbing the wire to rip it off, mistake, resulted in the smell of human flesh burning, over and above the acrid smoke. That stench stayed for a while.

The scissors I grabbed to cut them, ... mistake, do not use metal objects ... 1 pair of scissors, destroyed.

In the end I had to step back, take a deep breath, calm down, then find the spanner and proceeded to carefully disconnecting the battery pole connector.

Luckily nothing was damaged bar my ego.


I teach my kids: If you are stupid, your body is going to pay the price. Lessons above proved that beyond any reasonable doubt. :-)

waynefromnscanada

Re: The Wrong Components

And then there was the time I was installing my first "real" battery bank, using wrenches to tighten the nuts/bolts securing the various battery cables. No need to cover all the terminals I wasn't working on, I knew how dangerous it would be to rest a metal object (wrench) across those terminals, so wouldn't do it. Only someone stupid would do that right? And I was correct - - until I was wrong, and that happened when a wrench slipped out of my hand and landed - - that's right, you guessed it.
The explosive blast of current flow, along with melting terminals and parts of the wrench, or was it my guardian angel, threw the wrench off the terminals and the event was over as quickly as it started. I'll never know why the battery didn't explode, the flames were all over the vent holes in the fill caps.
It was then I decided that perhaps I should do as told and cover the battery tops with a blanket, leaving exposed only that terminal on which I was working.
Seems some folks enjoy learning safety practices the hard way.

RandomJoe

Re: The Wrong Components

Not solar-related, but power-related. This fun chain of events happened over the past few months, ending just a couple weeks ago.

We have one customer with an air-cooled chiller outside an auditorium. They don't exactly know what maintenance is... The chiller had a hard life and needed a LOT of work. We replaced the compressors, expansion valves, a couple control boards and got it running. Then the fun began! Among a number of crazy events, the most head-shaking were:

The chilled water pump died. Investigate, find the underground conduit bringing power to the pad has gone bad and shorted one of the wires to ground. We notify the customer (they are the HVAC maintenance guys for the facility) and they say they'll fix it. When we come back we find they ran ONE 12-gage wire - white, no less! - in OPEN AIR around the perimeter of the room. It enters the pump starter at one end, the switch gear at the other. They were still using two of the wires in the underground conduit. (This is a 460V 3-phase motor!) Another wire grounds out in the conduit, so they stretched ANOTHER wire (black this time) around the room - but NOT alongside the first! What the HECK???

The starter soon died as well - bad contactor coil - and instead of fixing it they just jumpered power-in to power-out, eliminating the overloads. The motor died a couple weeks later...

But the coup de grace was when they finally said they had everything ready to start the chiller (we hadn't been able to do a proper startup due to all the other issues). We arrive, turn on the disconnect, missing a phase! "Oh, yeah, one of the blades in the disconnect doesn't always go in. Just hammer on it and it'll go in."

Of course my boss says no way in h-e-hockysticks so the guy comes out himself, picks up a hunk of damp 2x4 (it had been raining earlier that day), opens the disconnect (again, 460V 3-phase, something like 300A fuses) and hammers on the dodgy blade with the 2x4! Everyone else is busy backing far far away...! When asked about it the guy even admitted that yeah, he'd been shocked "a bit" when he did the same procedure a few days before!!!

Geez... This guy has always been a bit - eh - lax? - when it came to safety, but I'm thinking he's gone off the deep end now...

OceanArcher

Re: The Wrong Components

Again, a power issue where the safety rules, improperly applied, could have been catastrophic ...

Working in a marine environment, on very large equipment (480v, 3-phase, input breakers rated at 500amps). System needed to be secured to perform maintenance. Equipment was shut down, and the journeyman electrician was instructed to obtain the insulated grounding rod, and bleed off the residual charge on the input filter bank. I was waiting for the "all clear" when I was greeted with a tremendous arc/flash and accompanying report from the other side of the compartment.

Upon rushing to the source of the disturbance, I found a the dazed journeyman standing in front of the opened filter enclosure, holding the insulated grounding rod which was now missing nearly an inch of rod. When I asked him what happened, he said, "I waited until the equipment was shut down, then I opened the filter enclosure, connected the grounding rod and tried to bleed the filters - just like this..." AND HE DID IT AGAIN!

Needless to say, we were treated to a second round of flash/bang. After the additional excitement settled down, I asked him where his safety check-off list was. He said that it was at the other end of the compartment, but that was OK, as he remembered what it said. I corrected him at that point, and motioned to the main feed breaker that had not been secured nor had it been tagged out in accordance with the safety check-off list. Fortunately no one had been injured, but everyone has to remember, safety check-off lists are there for a reason...

mike95490

Re: The Wrong Components

Glad he's not an airline pilot !