On becoming an electrician

The frightening part is just how little current can kill you.

With the higher voltages, you have to start worrying about it jumping across air gaps, and needing better insulation. For 120v I feel like rated boots, being dry, and not grounding out your dumb ass with your off-hand, those kind of things will keep you safe enough. But once you get over 600v that starts to mean little, if anything.

I was on a site years ago, and I was joking about breaking out a rubber mat for me to stand on. Dudes looked at me dead serious, and said they weren't allowed to use them any more because they wanted everyone to LOTO instead (funny enough, what I was working on was definitely live). I imagine that, given a choice, a lot of folks would have chosen the rubber mats and to leave stuff live...so NOPE! can't use them any more. That's the only time I've heard that, but I also haven't seen rubber mats in years (besides what linesmen use)

At least with 120v, I've never felt 'frozen'.

When/if I retire, part of the celebration will they that I somehow managed not to kill myself when doing something stupid

Borzak said:

Speaking of phases. I saw something that was odd to me but probably an every day thing for electricians and such. Company was hooking up some new heavy equipment to 3 phase. The new shit, had a info panel that would tell you when it was hooked up and turned on that the phases were on the wrong lug and had a diagram come up and tell you which one to move to where.

I'm a luddite, was new to me.

End result it took no time at all to change and booted up and then I was using the new equipment which was why I was there.

Click to expand...

If it's just a motor load, then like Kobayashi said you can just swap any two leads. We always swapped A and C, because that's what usually gets swapped inside reversing starters, I guess. B phase usually stay as B phase on both the Line and Load side of most 3-phase reversing starters. But if it's just a motor load, you're just looking for correct rotation. So you can 'bump' it, see if it's CW or CCW rotation, and if that's wrong then swap two leads.

Since it sounds like whatever you were using was more than just a motor, so it could have had some fancier stuff in it. Sensing a lost phase is pretty easy (single phasing) and we used to wire in phase detectors to trip out starters if you ever lost a phase (this kills motors). A newer option is a phase-loss, phase-sequence relay. This, or something similar, is probably what triggered your fault (internally).

Knowing what your equipment actually was, would probably tell us 'why' it had that warning. A lot of centrifugal pumps, screw compressors, some chillers/HVAC equipment, there's a lot of stuff that can be ruined by running stuff 'backwards' from having the wrong phase sequence. You might not even know what individual component inside your "big ass equipment" might be ruined, if it's all enshrouded and complex. But there is a real issue with a lot of stuff.

I've had NUMEROUS service calls where the electricians took the 'bad equipment' out, and dutifully labeled everything. When I show up to install the replacement, they assure me that all I need to do is read their labels and wire the new stuff in the same way the old equipment was. So I do...and the new equipment runs backwards. For the stuff I usually work on, it's not a huge deal, as long as I'm watching for it and can shut it down before a $50k-$100k valve gets destroyed. I don't think it's the fault of all those electricians, I just think there's either an unintended phase-swap in the controls themselves, or maybe it's just how a specific motor transitions the windings out to the motor leads (maybe someone at CheapMotorFactory DGAF what they labeled as T1, T2, T3 because they figured "hey, I don't get paid enough to care, let the field electricians figure it out")

Regardless, that's my guess. An internal phase sequencer saw the phasing was wrong, threw a fault back to the controls (maybe just a mini/micro PLC) and then you get the neat display error.

You can also wire a phase 'corrector' using a phase sequencer, at the 'electrician' level, using a reversing contactor. But instead of wiring the the phase sequencer back to your controls, DCS, PLC, etc, you just wire the phase sequencer back to a reversing contactor that's added for the sole purpose of changing ABC phasing to CBA phasing. But if you're an electrician thinking that this is needed, then some engineer will probably want to include themselves (LOL)

I'm starting at a new place next week. If they don't let me keep my old hardhat and insist I use a new 'tourist' company hard hat, I think I'm gonna buy some stickers because fuck it.