Electrician Talk - Professional Electrical Contractors Forum - Commercial Electrical Forum http://www.electriciantalk.com For topics that are specific to commercial electrical work en Mon, 06 Sep 2010 04:34:59 GMT vBulletin 60 http://www.electriciantalk.com/images/misc/rss.jpg Electrician Talk - Professional Electrical Contractors Forum - Commercial Electrical Forum http://www.electriciantalk.com Quick question... http://www.electriciantalk.com/f30/quick-question-16315/ Sat, 04 Sep 2010 15:15:41 GMT First post... I must admit that I have been away from electrical work for quite a spell. My experience was mostly in commercial with a majority of... First post... I must admit that I have been away from electrical work for quite a spell. My experience was mostly in commercial with a majority of jobs being restaurant remodel.

I also admit that I am NOT a licensed electrician. I am helping a close personal friend (at no charge) to do a few mods to a building that will be a little take out restaurant.

I need to run some #6 for a residential type range.

My question regards type of wire allowed on current code for use in restaurants. The existing EMT is only 3/4" and has several circuits of #12 already so no room for the #6 conductors.

Will NEC allow the use, in commercial restaurant, of #6 SER overhead in a typical drop ceiling?

Trying not to cut open walls etc.

Thanks in advance...
Brent ]]> Commercial Electrical Forum hogdogs http://www.electriciantalk.com/f30/quick-question-16315/ white in SO cord as 3rd phase conductor http://www.electriciantalk.com/f30/white-so-cord-3rd-phase-conductor-16312/ Sat, 04 Sep 2010 12:33:53 GMT Hello All, I am new to this forum and this may be a dumb question but here goes: If I am wiring a 208 volt 3 phase piece of kitchen equipment that... Hello All, I am new to this forum and this may be a dumb question but here goes:
If I am wiring a 208 volt 3 phase piece of kitchen equipment that pulls 33 amps and will run more than 3 hours (continuously) I multiplied by 125% which is 41 amps so I sized my breaker to a 45 amp 3 pole and will be using 3 #8 copper THHN wires with a #10 green ground. The appliance came with no cord so I was going to use 8/3 with ground 4 wire SO cord on the equipment with a male plug. Can I mark the white wire in the SO cord blue for my 3rd phase? Also can I use a 125/250 volt 4-wire range cord with male range plug on it and a flush mount 4-wire range receptacle using the silver neutral terminal as my 3rd blue leg? I don't do much 3 phase work and may be looking at this all wrong. Is there a different type of cord with 3 colors and a green, no white, that I should be using? Do they make a 3 phase 4 wire receptacle and male plug just for such a 3 phase application? Hoping someone can set me straight. Thanks for any advice. ]]> Commercial Electrical Forum TBarwick1 http://www.electriciantalk.com/f30/white-so-cord-3rd-phase-conductor-16312/ Commercial Kitchen Fire Supression Systems http://www.electriciantalk.com/f30/commercial-kitchen-fire-supression-systems-16297/ Fri, 03 Sep 2010 21:51:20 GMT I've only done two of these before and each one was slightly different.

The 1st one I did, I needed to shut down the back wall receptacles located under the hood. I ran a dedicated circuit to the coil of a 3 pole contactor. I interrupted 3 existing outlet circuits and landed them on the the l/l terminals of the contactor. I energized the coil circuit and I was done at that point. Fire guys ran wiring at a later date to interrupt my coil voltage.

The 2nd one I did all I had to do is turn off the MAU. Sort of the same setup with the contactor except I had to wire up the micro switched to aux contacts on the contactor.

Both of these setups passed by the FM.

I did a job walk this morning regarding a small hood. All that needs to be controlled is a dedicated circuit for a convection oven. Circuit feeding the oven is approxametly 150' away. Do I need to run a dedicated circuit for coil voltage or could I use the circuit for the convection oven? All I have to do is do the setup like I did the 1st one. Fire guys will break where needed. Could I take the convection oven 120 volt circuit to the coil 1st, tap off of from there to hit the line side of a contactor and then load side to the oven? Then the fire guys could interrupt my wiring from the feed to the coil to drop everything out. Electrically it would work, just don't know if it will fly or if I do need a separate dedicated control circuit.

Thanks, I'm off to my boys 1st high school football game, so I will check back later tonight. ]]> Commercial Electrical Forum knowshorts http://www.electriciantalk.com/f30/commercial-kitchen-fire-supression-systems-16297/ 277 VAC question http://www.electriciantalk.com/f30/277-vac-question-16294/ Fri, 03 Sep 2010 17:42:30 GMT I've found that I have a 277v lighting circuit in a bathroom at my facility. My CEO has her heart set on a certain light fixture from Lowes.

The fixture would normally be used in a 110V application, but can I wire it to 277V and use 277v light bulbs?

Thanks, hud ]]> Commercial Electrical Forum hudlow http://www.electriciantalk.com/f30/277-vac-question-16294/ CEC question... Bonding a step-down transformer http://www.electriciantalk.com/f30/cec-question-bonding-step-down-transformer-16287/ Fri, 03 Sep 2010 11:06:27 GMT In the 'things that make you go 'hmmm'' category, I was just wiring up step-down transformers that are taking 15A of 600V and producing 40A of 220V. The book says the primary side of the transformer can be wired with 14ga THHN, and it can be bonded with the same. But if the secondary side is producing 40A, then doesn't the primary side bonding need to be big enough to handle the potential fault current? I can't find anything in the book that covers this situation. Any thoughts?

Mike ]]> Commercial Electrical Forum Mike in Canada http://www.electriciantalk.com/f30/cec-question-bonding-step-down-transformer-16287/ Neutral connected to two panels??? http://www.electriciantalk.com/f30/neutral-connected-two-panels-16165/ Mon, 30 Aug 2010 18:49:39 GMT Hi,

Background. I normally do Home Automation in residential settings but with the advent of ZWave, I'm finding some applications in the commercial realm. Usually can't use X10 in commercial settings due to distance of line runs or 3 phase power. Since ZWave is a mesh network, distance can be overcome and 3 phase power isn't a problem since the ZWave devices just need power to run their own circuitry and communicate with each other via RF.

OK, now my question. I'm automating a gang of lights in a Church sanctuary. The switches are currently just hot loops to the lights (hot/feed comes down from light in conduit and no neutral present, the switch just breaks the hot/feed).

Most all ZWave switches require a neutral so the ZWave circuit has power so I have to run a bunch of new neutrals back to the panel for each circuit which isn't a problem since it is drop ceiling and a panel is near by.

The problem I discovered is some of the switches have a feed that comes from a different panel that is up stairs and hard to get to. So my question is ... is it OK if I run all of the new neutral wires for the ZWave switches back to one panel or do I need to run the neutral to the panel the hot/feed comes from???

Thanks,

Brian ]]> Commercial Electrical Forum hutchman http://www.electriciantalk.com/f30/neutral-connected-two-panels-16165/ going commercial and leaving residential http://www.electriciantalk.com/f30/going-commercial-leaving-residential-16161/ Mon, 30 Aug 2010 17:41:53 GMT i got a callback on from a fairly large commercial and industrial co. this am just waiting to hear what job ill be going to,,,,it wasnt easy to get.... i got a callback on from a fairly large commercial and industrial co. this am just waiting to hear what job ill be going to,,,,it wasnt easy to get. i had to pass a background ,drug screen and had refrences from g.c.'s..its a few dollars more with benefits,vacation time and paid days off for x amount of days there..very structured company so on the job should go alot better than residential.....for today im just thankfull for a chance to better myself in my field....and to be out of houses for a while. ]]> Commercial Electrical Forum zen http://www.electriciantalk.com/f30/going-commercial-leaving-residential-16161/ <![CDATA[20' long conduit]]> http://www.electriciantalk.com/f30/20-long-conduit-16158/ Mon, 30 Aug 2010 14:40:42 GMT I was in a supply house a couple weeks ago and saw a couple bundles of 20' long 3/4 Emt. After taking a pic of it the guy said he could get it in any size 1/2 thru 4. I thought it was pretty neat so I thought I would post a pic of it.
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]]> Commercial Electrical Forum william1978 http://www.electriciantalk.com/f30/20-long-conduit-16158/ Can someone explain the secondary of a 120/208v transformer to me? http://www.electriciantalk.com/f30/can-someone-explain-secondary-120-208v-transformer-me-16146/ Mon, 30 Aug 2010 02:32:00 GMT A 120/240v single phase transformer makes perfect sence to me. the neutral comes from the center tap of the 240v winding. but obviously the neutral... A 120/240v single phase transformer makes perfect sence to me. the neutral comes from the center tap of the 240v winding. but obviously the neutral on a 120/208v system doesn't come from the center of a 208v winding, you'd have 104 volts. someone please explain! ]]> Commercial Electrical Forum speedfreakian http://www.electriciantalk.com/f30/can-someone-explain-secondary-120-208v-transformer-me-16146/ Commercial steel stud romex installation http://www.electriciantalk.com/f30/commercial-steel-stud-romex-installation-16144/ Mon, 30 Aug 2010 01:37:22 GMT So am i a hack? I made some good money with a cheap bid. :thumbup: So am i a hack? I made some good money with a cheap bid. :thumbup: ]]> Commercial Electrical Forum Shockdoc http://www.electriciantalk.com/f30/commercial-steel-stud-romex-installation-16144/ Pulls with multiple drops http://www.electriciantalk.com/f30/pulls-multiple-drops-15968/ Sun, 22 Aug 2010 10:54:08 GMT When doing pulls through conduit with multiple drops, what do you feel is the best/easiest way to do it? Do you radically oversize the conduit so... When doing pulls through conduit with multiple drops, what do you feel is the best/easiest way to do it? Do you radically oversize the conduit so that you can pull the drops individually and have a prayer that they don't snag inside the pipe? Do you pull it all at once, drop your drops and tie them off at the pulling end so they don't get dragged in and snag?

I recently did some really, really ugly pulls (9 drops), so I'm curious what you guys feel is the easiest way.

Mike ]]> Commercial Electrical Forum Mike in Canada http://www.electriciantalk.com/f30/pulls-multiple-drops-15968/ Problem with emergency light fixtures and battery.... http://www.electriciantalk.com/f30/problem-emergency-light-fixtures-battery-15937/ Fri, 20 Aug 2010 21:01:10 GMT Hey i have a parking garage at the casinos i work in and in the garage we have Lithonia emergency light fixtures CAT# IND12150 and the Lithonia... Hey i have a parking garage at the casinos i work in and in the garage we have Lithonia emergency light fixtures CAT# IND12150 and the Lithonia batteries (ELB 1255)were going bad because of the cold weather and them freezing you can see the batteries swelling. So we purchased battery heat blankeds a few years back and have been gradually installing them when we have time to do so. Someone in the department ordered replacement batteries for these fixtures but they are not the (ELB 1255) battery they are called Power Patrol CAT#1165 12V55Ah Sealed Maintenance Free Rechargeable Battery AGM, Non-Spillable. we installed some of these batteries in the emergency light fixtures and the self diagnosis shows a solid red light which means its charging the battery when fully charged should turn green but they have been charging for 3 days and still solid red and when you press the test button the lights do not come on the diagnosis flashes red and green meaning insufficient charge. Are we not able to use the batteries in this fixture or what seems to be the problem? I checked the fuses on the lights and they are good all the power is good. Help? ]]> Commercial Electrical Forum cshady143 http://www.electriciantalk.com/f30/problem-emergency-light-fixtures-battery-15937/ Triggering 110V with 347V http://www.electriciantalk.com/f30/triggering-110v-347v-15934/ Fri, 20 Aug 2010 17:36:56 GMT I wanted to start a 120V ceiling fan whenever the 347V lighting was turned on. I considered various ways to do it, but none were easy to source. I... I wanted to start a 120V ceiling fan whenever the 347V lighting was turned on. I considered various ways to do it, but none were easy to source. I could use a transformer to get 110V from the 347V and wire it in with the lights - no switching required. I could try to find a RIB relay with a 347V coil, or I could put a photo-eye on the ceiling fan. What would be considered the 'standard solution' for this problem?

Mike ]]> Commercial Electrical Forum Mike in Canada http://www.electriciantalk.com/f30/triggering-110v-347v-15934/ commercial piping http://www.electriciantalk.com/f30/commercial-piping-15841/ Tue, 17 Aug 2010 14:31:24 GMT I am moving from residental to commercial work and had a quick question. If I pull 3 current carrying conductors (black, red, blue) in one pipe... I am moving from residental to commercial work and had a quick question.

If I pull 3 current carrying conductors (black, red, blue) in one pipe can I run one neutral conductor and still put them on 3 single pole breakers or do i need to have a 3 pole breaker. And where in the NEC talk about this. ]]> Commercial Electrical Forum may electric http://www.electriciantalk.com/f30/commercial-piping-15841/ Electro Vox Interm http://www.electriciantalk.com/f30/electro-vox-interm-15811/ Mon, 16 Aug 2010 15:02:50 GMT has anyone a schematic for the old 5 wire electro vox apartment intercom? Probably cheaper just to replace but customer wishes to try to repair... has anyone a schematic for the old 5 wire electro vox apartment intercom? Probably cheaper just to replace but customer wishes to try to repair first.

Thank you ]]> Commercial Electrical Forum BwFrench http://www.electriciantalk.com/f30/electro-vox-interm-15811/