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Author Topic: Two Electrical Services in one Building  (Read 12448 times)

Mark Cadwallader

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Re: Two Electrical Services in one Building
« Reply #40 on: February 08, 2016, 11:14:10 PM »

I choose to wear a full face helmet, fully armored suit, gloves and boots while riding my motorcycle, regardless of how hot it is, but that's my personal decision. I don't know when I'll need it, but I want it there. Level III body armor isn't particularly cool, and most law enforcement officers will never need it, either, but department policy says to wear it, because you never know when you'll need it.  YMMV, but it is a reasonable thing (IMO) for an employer to require PPE.
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Tom Bourke

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Re: Two Electrical Services in one Building
« Reply #41 on: February 09, 2016, 02:08:43 AM »

I certainly didn't mean to imply that you should be flippant about gear.  I have worn FR coveralls over jeans and a long sleeve shirt hard hat and faceshield on a hot August day in Iowa inside a factory-no fun at all, but the hazard called for it.  I have also refused to wear fall protection when technically required-but there was no provision for an anchor point and management indicated I should use an anchor point roughly 9 feet off the floor-so they could check their box that we were following procedures.

Arc flash gear needs to be worn when the hazard requires it-but management mandating use of gear when there is truly no hazard present is silly.  The "I don't care how miserable or uncomfortable your job is, I'm not going to make the effort or expend the energy to  figure out how to do this best" sends the message that safety is really not as important as the temperature of the AC in the office.  Many times, I have seen overbearing safety mandates given lip service-so there is no real safety improvement. You need to take safety seriously enough and care enough to do it right-even if it takes more effort to understand it.
Today was an interesting day in regards to this conversation.  Nothing bad happened and I hope the safety concerns I raised are followed up on.  I know I will follow up on them.

Did a load out for a "the big game" party.  Felt no need at all for the blue fire shirt, however policy says I need it for ALL power above 125V so I have mine on just so I don't have to wait for some one to walk from the other end of the convention space.  150 ft run of feeder to a 400A lunch box distro for projector power, cool.  Proper procedure followed.  Individual loads off, little to no current flow, knife it off while standing to the side and facing away.  Did some other smaller power, what ever.

Late in the day I walk in on a conversation about some "special plug" on the catering hot boxes for the next event.  Look at the cell phone pic and it is an Edison with one blade side ways.  Umm OK, it is a NEMA 5-20 or a NEMA 6-20.  Not common enough that I know it by a glance.  If I see any Edison with a 90 blade I immediately go to the info plate on the device to see what the manufacturer says.  Seen too many items "repaired" with "that odd side ways plug."  OK 17.5A 120V and it is a NEMA 5-20.  Cool, how many? 25 boxes!?!?

OK, I have 100A 120/208 3phase  Hubbles and clear views.  Do the math and I come up with 12 boxes per 100A disconnect gives me 70A a leg.  OK, so 2 100A connections and a 1/2 dozen Circuits built into the wall gives me plenty of power.  I put my load calcs in sharpy on white gaff on each clear view and tape off the extra circuits with "at max load" written on it. Good to go.  Get every thing plugged in and powered up.  Clamp meter the current draw on the cams and 50 to 60A per leg plus 6 to 12A per neutral depending on how the thermostats are calling for heat.  Cool, makes sense given my calculations and the fact that not all boxes are the full 17.5A.

And now my safety inspection.  1 box was missing a ground.  It and another box set off my Fluke  NCVT and measured at 25V between it and the next box over on my Fluke 225.  One other box had a cracked cord end.  5 other boxes had cord ends too hot to touch after 30 min.  Over all I red tagged 1/3rd of the units.  Out of all of that I feel the fire retardant shirt gave the most protection from the 2 hot skin units.  Not from flame or arc flash but from my elbow  touching it.  By far the largest safety measure was me understanding the situation and doing appropriate, load calcs, visual inspections, and measurements.  My fresh hire co worker was at total risk since he had limited understanding of the risks at hand.
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Mike Sokol

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Re: Two Electrical Services in one Building
« Reply #42 on: February 09, 2016, 08:30:08 AM »

And now my safety inspection.  1 box was missing a ground.  It and another box set off my Fluke  NCVT and measured at 25V between it and the next box over on my Fluke 225.  One other box had a cracked cord end.  5 other boxes had cord ends too hot to touch after 30 min.  Over all I red tagged 1/3rd of the units.

My son is in culinary, and we find that kitchens can be electrically more dangerous than performance stages. There's lots of grounded metal (stainless steel tables, etc...) and lots of metal chassis appliances (mixers, refrigerator, hot boxes, etc...). Plus many of these heating appliances run for extended periods at full rated amperage. So instead of a sound system with maybe a 1/8 ratio of actual power draw, if that portable hot-box is rated for 2,400 watts, it's going to draw 2,400 watts for hours on end sometimes. Add to this that kitchens are wet all the time, and there's always a rush. One of the first things I gave my son when he went to culinary school was a Fluke NCVT to check for electrically hot chassis in the kitchen, and made sure he knew how to inspect appliance plugs for any exposed wires, burnt contacts, melted insulation, etc...

Chris Hindle

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Re: Two Electrical Services in one Building
« Reply #43 on: February 09, 2016, 08:36:40 AM »

Your comment reminds me of an advert that we're getting at the moment.

YouTube link.
David, that advert is brilliant. Don't know what planet you'd be from to not understand the message.
An awful lot of safety is "inconvenient", right up to the moment that it saves your life.
Chris.
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Ya, Whatever. Just throw a '57 on it, and get off my stage.

Stephen Swaffer

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Re: Two Electrical Services in one Building
« Reply #44 on: February 09, 2016, 11:37:15 AM »

I choose to wear a full face helmet, fully armored suit, gloves and boots while riding my motorcycle, regardless of how hot it is, but that's my personal decision. I don't know when I'll need it, but I want it there. Level III body armor isn't particularly cool, and most law enforcement officers will never need it, either, but department policy says to wear it, because you never know when you'll need it.  YMMV, but it is a reasonable thing (IMO) for an employer to require PPE.

I agree 100%-in both examples the hazard demonstrably exists-for you as soon as you step on the motorcycle, and for the officer-especially these days-as soon as he puts on his uniform.

In every building I have worked in that has had arc flash studies done, the results are eye opening.  In a manufacturing facility using 480 volts and tons of 20, 30 and 60 amp circuits most everything was Level 0 (at that time)-and the hazard existed for only a few inches making gloves more important than a shirt.  That said, without a study you can't say a given circuit is OK because far more has to be considered that just the ampacity and voltage of the circuit.  By investing in a study, you not only can properly inform employees/contractors-but you also know where and why the hazards exist.  Far better to eliminate or mitigate the hazards (sometimes as simple as upgrading the OCPD) than to ratchet up the PPE requirements just to be extra safe.  On the other hand, I think skilled employees need to understand and be able to recognize hazards so they can recognize situations that really call for more PPE that the "book"says.  Tom's example of working with the food service boxes is a good example-OSHA might not have technically required PPE, but anytime I am working with electricity I don't like to have skin grounded by touching any metal object so I long sleeve shirt and gloves if you are touching something metal-even a hard hat in a low clearance situation might me a good idea.

I don't feel like "inconvenient" is a good excuse for anyone not to use PPE.  But from a management standpoint, unnecessary inconvenience will make it more likely an employee will ignore requirements when it reallyis necessary.
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Steve Swaffer

Jeff Bankston

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Re: Two Electrical Services in one Building
« Reply #45 on: February 09, 2016, 03:18:57 PM »

The same sort of management nonsense which now has our street cleaners wearing hard hats for no apparent reason.


Steve.
and job sites where theres only a dirt lot and the guys measuring and putting markers for where the foundation is going have to wear hard hats in case the sky falls. a guy i know wrote a worker up for walking across an empty lot holding his hard hat in his hand. i got yelled at by a job superintendent for taking my hard hat off while i was on the roof.
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Jeff Bankston

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Re: Two Electrical Services in one Building
« Reply #47 on: February 09, 2016, 03:26:14 PM »

Has the city got something against you ? Thats really strange to not allow you to install a larger new service. If I were in your situation I would order a 480V A/C unit.
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Re: Two Electrical Services in one Building
« Reply #47 on: February 09, 2016, 03:26:14 PM »


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