Check packing lists, then meter the power

[Radiant]

We installed 8 new PAR 56s today in one of the kids' buildings we're renovating. The debut service is tomorrow morning. It should've been 24 PARs, but the shipment was royally screwed up. We received two dimmer packs of the eight ordered, some random PAR 64 lamps that we didn't order, not enough clamps, and not enough safety cables. So with those 8 cans, I'm able to do only front light - no architectural light, no backlight. Bleh.

Ahh, but the power is, umm, interesting. We have seven circuits at our disposal, and I checked them all with my little polarity tester, and everything looked fine. But when I plugged in our spiffy new Elation Stage Setter 8, it didn't light up or function. The intern working with me moved the DC converter to an adjacent outlet, and noted that it was scorching hot. Long story short, about one third of the outlets are carrying 210 volts. It's completely random. There might be one 210 in a group with three 120's. Or all 210. I then remembered that I'd plugged in the dimmer packs (all two of them! Both!), but they don't appear to have suffered any damage.

It fried the DC converter for the console, but not the console itself. A quick dash to the corner Radio Shack, and I had a new white wall wart. I don't own a multimeter, but I will - tomorrow.

 

[MNicolai]

Sounds sketchy. You may want to not only find out which outlets are 210V (or any other voltage for that matter), but specially mark them. It's odd; my experience with any voltage besides 120V is that it should be designated with a different receptacle style. You may also want to use a circuit seeker or tone generator, if you have one, that works on various voltages to find out where the circuits go and see if there's another story with them, like they intended to run phase/neutral but "accidentally" ran phase/phase off of a double-pole breaker.

What kind of receptacle are they?

 

[Radiant]

What kind of receptacle are they?

They're all 15 amp Edison outlets. One of the guys tonight said they had some computers die when that building was last used. I think we know why now.

I asked they guy with the meter to mark everything 120, 210, etc. with a sharpie. I taped over the offending outlets, informed the facilities staff member, the kids' room directors, and a couple of the tech people who will be operating lights and sound in that room. I asked that we have a bona fide electrician come out and rectify this mess. We're fortunate that the total loss was about $25 for the Radio Shack converter. Other folks had already assembled the sound system and tested it a couple days ago, without incident. We easily could've roasted everything, and never known why.

Just remembered - a fella had his DeWalt charger blow up tonight. Literally, it tossed sparks about ten feet. That's when I tested every outlet with my polarity tester, thinking that was sufficient.

What's odd is we were just granted our occupancy permit by the city, following moderate renovations to the entryway, floor resurfacing, and other stuff I'm not really aware of. But wouldn't an occupancy permit inspection include metering a few outlets? Literally, one third of the outlets are over-voltage!

I'm pretty steamed. This whole thing is so sloppy.

 

[MNicolai]

Typically not. I think it's a given that in an existing building, there aren't any voltage surprises on 15A outlets. If you trace the voltage feed to a feed panel and they're feed via a double pole breaker, and were fed phase/phase instead of phase/neutral, you could get fix that so everything is 120V without having to replace anything. Inspecting would be as far as I would go, and then I'd have an electrician do the work. You might have a couple options though; feed 120V on the existing wires to the existing outlets, or keep the 208V and have proper receptacles installed to reflect the difference in voltage.

I would have an electrician inspect everything though. Wires that have been dead-shorted numerous times via blowing some 120V gear up may not be in the best condition. Additionally, those receptacles should be looked at for their condition; I'll bet they're rated ~120V, not 208V.

My first guess is still that a double-pole breaker intended to feed two branches of 120V was miswired and fed a single branch of 208V. That'd be the logical mistake if all of the outlets are edison at least. If that's the case, it's about 15 minutes to fix it and get your 120V feeds back. I'd still recommend you have them inspect and/or replace every receptacle fed the wrong voltages though to ensure no further problems later on.

 

[n1ist]

Sounds like you have a panel with a wild leg (110 to neutral on 2 phases, 208 on the third, usually "B" phase) and someone wired it up without knowing or metering. Time to get an electrician in to straighten things up.

For now, tape over the 208V recepts and turn off the breakers feeding them, or if you feel safe doing it, turn off the breakers, pull the recepts, cap off the wires and use blank plates.

/mike

 

[icewolf08]

Sounds like you have a panel with a wild leg (110 to neutral on 2 phases, 208 on the third, usually "B" phase) and someone wired it up without knowing or metering. Time to get an electrician in to straighten things up.

For now, tape over the 208V recepts and turn off the breakers feeding them, or if you feel safe doing it, turn off the breakers, pull the recepts, cap off the wires and use blank plates.

/mike

The ∆ (delta) power feed with wild leg is probably the most plausible idea. This is easy to test for with your meter. Just meter from each leg to ground. If you meter from hot to ground on a standard 115V circuit you should get 115V. From neutral to ground you should get 0V. If you have a two pole 208V circuit, both legs would meter 115V to ground and 208V to eachother. However, if you have a ∆ transformer then only one leg will meter 208V to ground and the other will meter 0V.

What was the building used for before you guys took it over?

 

[Radiant]

What was the building used for before you guys took it over?

We've owned the property for seven or eight years. We've previously used it for a kids classroom, then it was vacant for the last year or so. I'm not sure who the building's previous owner was, or their use for it. Our property comprises 6 total buildings over 25 acres. One building was demolished soon after purchase. It's an industrial area, so there likely was some need for 208 volt power, but what it was doing being fed through an Edison outlet baffles me. I don't think the church would've knowingly wired anything for 208. For what we previously used that room for, it wasn't needed at all.

Time to get an electrician in to straighten things up.

I've been muttering that for three days now...

I need to learn more about electricity. That's been one of my goals for the last couple of years. I'm learning slowly as issues come up, but it's still beyond my abilities to open up a breaker panel. I'll see about locating the breakers feeding the receptacles and shutting them off.

turn off the breakers, pull the recepts, cap off the wires and use blank plates.

Is that an acceptable electrical practice, open hot wires capped with a wire nut? That would be a quick and easy stopgap, until we get the electrician over.

 

[Les]

I need to learn more about electricity. That's been one of my goals for the last couple of years. I'm learning slowly as issues come up, but it's still beyond my abilities to open up a breaker panel. I'll see about locating the breakers feeding the receptacles and shutting them off.


Is that an acceptable electrical practice, open hot wires capped with a wire nut? That would be a quick and easy stopgap, until we get the electrician over.

Pretty sure you would need an apprentice license minimum to do the work. At least that's the way it is in the residential field. Residence and Commercial are like two different animals. I've thought about looking into some formal electrical training. Wouldn't hurt to know how a breaker box is wired up. I was an apprentice electrician for a few years and I did learn to wire up a residential breaker panel but again there's quite a difference between those and what you would find in a commercial panel. Not only that but there is such a difference from say a small church or something and a large office building or grocery store.

As far as I know, and I don't know that far, capping live wires is a legal practice, at least in my state. There may be a difference in commercial vs. residential. I'm really just taking a shot in the dark at this, so don't take it as any formal advice, but people delete receptacles and light fixtures all the time, and wire nuts and a few wraps of electrical tape at the end of the wire is usually how it's done. Again, I have my apprentice residential electrician cap on right now, and never did we ever have to cap off live wires inside a junction or wall box. So I really have never consulted the NEC. Honestly as long as your wire nuts are good and tight, it's not like the electricity is just going to build up pressure and blow them off or something.

 

[derekleffew]

When in doubt, consult a Licensed Electrician. Note that even the opening of a panel requires a Qualified Person, per the NEC. Let's be careful to not overstep our bounds and violate CB's Content Policies/Safety.

Radiant, and anyone else, I suggest you LURK at http://forums.mikeholt.com/. Lots of good information there, but the board is intended for professional electricians, not do-it-yourselfers.http://www.controlbooth.com/forums/members/radiant.html Ninety percent of the questions are about some form of code-interpretation. Mike Holt makes a living by writing books and giving lectures on the NEC.

 

[TimMiller]

the 208 delta leg is never used by itself, and should not be used by its self under any circumstances. It is there to aid in the starting of 3 phase motors. Getting your phases off by one leg with the wild leg can get you into all sorts of problems. I would definitely get an electrician out, who knows your lights may be living off of a leg of 208V. Tell them right now there is nothing stopping someone from accidentally plugging something into the wrong outlet and getting shocked, or the building catching on fire. A leg of 208V can do a lot more damage before the breaker kicking off than a leg of 120V. If someone does get hurt the lawsuits will not be pretty and will run against your church as gross negligence. I am sure there is a member of the church who is a licensed COMMERCIAL electrician who will be more than willing to help.

 

[SHARYNF]

I have seen on occasion where a building is wired for 220 into the rooms perhaps for window air conditioners etc etc. At some point the decision is made to change things and standard edison outlets are installed, with the remaining hot leg simply wire nutted off. Problem occurs when say at some point someone decides to change the outlets or something and someone makes a mistake and connects up the outlets incorrectly.
Again as I said even in homes outlets with 220 or 208 for ac units are pretty common. It would be interesting to meter and see if what you have is 120 on each of the legs referenced to ground, VS 220 on a single leg referenced to ground.

IF you have 120 on EACH leg, then it is likely as I suspect someone hooked up either the outlets incorrectly using the additional wire that was intended for 220 OR someone was working on the electrical panel and connected the wires incorrectly (some one might have at one time not used the standard of white for neutral, and someone connected it to a breaker, or a neutral wire has come loose from the neutral bar and is now connecting to a hot side of a breaker.

If you have 220 or so on a single leg to ground then you are likely connected to the wild leg on a delta system, where some one made a serious mistake.
It is not all that uncommon where someone is used to wye service for three phase, and then connects things up not realizing that delta is very different, and causes this exact problem.

Get an electrician right a way to check things out

Sharyn

 

[Sony]

The question I'm thinking is..."Why is their Delta Power in a building." I always thought Delta power was most common on ships...never heard of it in buildings before. I think it's more likely that 2 legs of a regular 3 phase system got connected to a series of outlets by accident.

 

[SHARYNF]

Delta is also used on occasion where there are alot of motors, or where the wiring is for a "mechanical room"

Simple metering should confirm which is the likely problem
any single pin in the outlet to ground over 120 then it is likely to be a delta connection on the wild leg
if it is the two pins in the outlet together then I would guess it is a neutral wired up as hot or a spare hot connected to the outlet by mistake left over from an earlier socket used for A/C or something like that

Hopefully we will get an update ;-)
Sharyn

 

[TimMiller]

Delta is common around many industrial buildings. I worked at a production company that appeared to be a house with a large warehouse attached, they had 208V delta. What ever you do, do not connect a single leg of 208 to a fixture then neutral to the other to create 208V. They let out a lot of smoke. Delta is great for motors, it really drops your starting amps, but drives you crazy when connecting up 120V circuits. If you are tieing in, remember the orange leg is the wild leg. (Black, Red, Blue is 120/208V Y), (Black, Orange, Blue, or Black, Orange, Red is 120/208 Delta) Always meter any power before plugging in even if its just plugging in a furman with an LED voltage meter (btw they work really well for testing out confetti cannon wiring without actually setting off the cannons)