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#50102 03/23/05 08:30 PM
Joined: May 2003
Posts: 2,876
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e57 Offline OP
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Been doing some work on a building for about a year doing odds and ends maint. stuff. For some reason ballasts and lamps are short lived. Lamps (flouresent) last about six months, same for HID. Incandesant either burn out after 3 months, or explode. Ballast seem to last about 6-9 months. Its not every light, but an inordinate amount of them.

Any ideas?

Harmonics? (Neutral = 700Hz - 1.2kHz, 3 phase Y)
Ghost?

Same place has some major equipment, lots of HVAC, motors. 3 elevators, etc. (One elevator has some issues... pulls 650A in-rush, and sounds like the four hoursemen. No-one knows why.)


Mark Heller
"Well - I oughta....." -Jackie Gleason
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... Job security,don't knock it..!! [Linked Image] [Linked Image]
Russ


.."if it ain't fixed,don't break it...call a Licensed Electrician"
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Bad conections on the neutral? If the neutral is bad, some circuits could see excessive voltage, thus blowing out the lights, etc.

Joined: Jun 2003
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D
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When in doubt, blame Elvis:

[Linked Image from populus200407.omnis.ch]

Of course, if you went to ULC and got ordainied, you could charge them for an exorcism:

[Linked Image from populus200407.omnis.ch]

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e57,
Hmmm,
Sure sounds like there are some power quality issues at that place.
I'd be checking the Neutral bus for a start.
Failing that, I'd get some sort of a Power Analyser connected to the Mains, to see what is happening.
Doug,
Looks like someone found the smilies webpage OK. [Linked Image] [Linked Image]

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e57 Offline OP
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Trumpy, thats more along the lines of what I want to hear. I have been wanting to do some PQM on this building since I first heard the elevator conduit rattle. Cant get anyone to pay for it though...

I just got done with 2 TI's there, and while there started doing ballast replacemnts for, and around the building. The building was gutted 'bout a year and a half ago, and it seems like anything with a transformer is on its way out. Makes me worry about waranteeing all my work there.

[This message has been edited by e57 (edited 03-25-2005).]


Mark Heller
"Well - I oughta....." -Jackie Gleason
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Posts: 8,407
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e57,
Quote
and it seems like anything with a transformer is on its way out
From that statement, I'd say that your problem is more than likely a Harmonic one.
Harmonic currents in a Transformer cause the windings and core to overheat.
What sort of motor controls are used on the Elevators?.

Joined: May 2003
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e57 Offline OP
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Soft start at 650+ amps!

Which is soft enough considering the data for the motor has LRA at 1300.

I had a post about it a while back, and was going to update the info, but cant find it.

Our silly PM is bidding to re-pull the conductors for it, against my advise. (I don't think it will solve anything, I have suggested PQM from the beginning.)Sometimes working for someone else is like wearing hand-cuffs. She thinks I'm a "Negitive Nancy", I think she should lay off the Prozac, and look at things objectively.

Today, I saw an HID fixture drop out as the elevator started! (You know when the elvator starts by the extreme "Short" sound when the conductors rattle in the conduit.) That has some confirmation for me for voltage drop due to waveform distortion. The elevator rep. and contrctor who did the base build have been fighting about it since day one. Mmmmm Politics!

They also have a bid to change out a UPS that hums so loud they can't rent the space near the room it is in.

If it is Harmonics, I just added 100 work stations, lots of flouresant lighting and several large motors to the mix, with my 2 TI's. We have a meter available, but need 3000A CT up-grade for testing this service, money the PM sees no need for.

If its a neutral problem, I think it is in the main, as the problem seems to be building wide, which also puts our work at high risk. PM not interested in spending some time with a thermometer. In fact, not interested in trouble-shooting at all.

Anyway, I should stop, I'm starting to _itch.


Mark Heller
"Well - I oughta....." -Jackie Gleason
Joined: May 2003
Posts: 74
J
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Bad conections on the neutral? If the neutral is bad, some circuits could see excessive voltage, thus blowing out the lights, etc.

Would this be an issue in residential as well, where the neutrals are NOT split?

[This message has been edited by jkraft (edited 03-26-2005).]

Joined: Jan 2005
Posts: 15
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Maybe the elevator wire is undersized,also you might try megging the wires

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