# Commercial wiring?



## 480sparky (Feb 1, 2009)

We Fix Houses said:


> ............I'll pass along another tip if you install machines and your concerned about grounding, residual electricity, PLC's, electronic controllers. You can source all the conditioners you want but driving a ground rod into the floor and attaching a ground wire from the frame is an excellent way to deal some grounding issues. This is in addition too, not a substitute for recommended machine wiring.


Please explain this one. :blink:


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## 480sparky (Feb 1, 2009)

BCConstruction said:


> Also trying to decided on the lights. I suggested around 10 metal halide 400w fittings but they are concerned with electric and start up time from hot and cold. Someone see that high pressure sodium lights have much sorter start up time from hot and cold but I'm almost certain they are the wrong color temperature light for in a warehouse. The light we were looking at were around 4k-6k but the sodium ones are About 2k.



Metal halides & soiumds will take 5-10 minutes to turn on, so you'll have a dark warehouse for a while. Add a couple fluorescents to provide enough light to get around until the HIDs get up to speed. Other down-side..... if there's a flicker in the power, they'll go off for up to 30 minutes.


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## We Fix Houses (Aug 15, 2007)

I researched this too. Wish I could remember all....? 400 w MH and HPS are hi - bay only. They now have 250 w low bay. High bay means they need to be mounted at least 16' above the work space. I assure you any less you'll be seeing spots all day. Not sure about the mounting height of low bay but I believe its about 12'. Of course MH is whiter, HPS is yellow and didn't make the cut. You need 208 / 277 v for the lights or they'll cost a ton of elec. 

I called my local Grainger outlet and they sent out an independent lighting consultant and gave us options and mapped everything out. It was no obligation but we did a lot of biz with them. Try to find a supply house that can do this for you. In the end the boss said to just buy one 250 or 400 w MH and see how it works. You'll use it some where. I did - too white and hard on the eyes for our people and product. We are what is called high inspection light, colors, etc so we went with flours. 

Oh yea......check your lighting voltage first ? Too many owners ordering lights not to the avail voltage ?

Hope this helps


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## 480sparky (Feb 1, 2009)

We Fix Houses said:


> .......You need 208 / 277 v for the lights or they'll cost a ton of elec. ..........


The voltage feeding the lights makes no difference on your utility bill.


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## The Coastal Craftsman (Jun 29, 2009)

480sparky said:


> No. NM (Romex) is for dry locations only. UF is for wet & direct curial.


Oh right. That means 6242y type cable is the same as romex then. Just looks the same as UF. http://www.rapidonline.com/1/1/24-twin-earth-cable-6242y.html

That's another UK-US term I now know. Its hard work keeping up with different terms for exact same stuff. Hard work talking to my UK mates when I use US terms on them.


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## We Fix Houses (Aug 15, 2007)

480sparky said:


> Please explain this one. :blink:


I can't intelligently say why but the previous plant manager of 30 yrs had evey enineer, rep, CH, AB, Siemens conditioner product recommended installed with machines, still had plc and resid load problems. As soon as they left he just hooked up the ground rod again and no problems for years on end. I will say many reps can't explain it either....?


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## The Coastal Craftsman (Jun 29, 2009)

The light I see where quad voltage so not sure how that will save me money using more voltage.


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## We Fix Houses (Aug 15, 2007)

480sparky said:


> The voltage feeding the lights makes no difference on your utility bill.


Please explain it to the op and myself so we'll know. I could be mistaken....it the watts regardless ?

The voltage allows more efficient use of the SE amps since it has limitations ?

You can clear it up for me.

I'm not an electrician.


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## Tinstaafl (Jan 6, 2008)

Higher source voltage will allow you to deliver power over a greater distance with a lower percentage of voltage loss due to resistance in the line. But if you're consuming 100 watts, it's still going to be 100 watts no matter what voltage you're using to deliver it.


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## The Coastal Craftsman (Jun 29, 2009)

Just reading some info about this quad voltage thing on the lamps. Seems that recommended RMS voltage is 280v on a 400w MH Ballast/bulb setup. so how does the light run on 120v. Does it use more current to deliver the higher Voltage needed to run the light? 

Reminds me of my rc car charger. I can charge a battery at 16v from a 12v source it just uses more amps than it would with a 16v source. Could this be the same for these fixtures?

So as an example if you were running a light at 240v at 6amps would a 120v bulb at 12amps cost twice as much to run than the 240v version?

If this is a yes then I understand why running higher voltage would save you money as you would need less current.


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## We Fix Houses (Aug 15, 2007)

Let me get my eraser out....

Single phase 120v x 20 amp breaker = 2400 watts x .90 safety factor = 2160 watts avail for that circuit. 2160 div 400 watt MH = 5.4 fixtures can be hooked up to that circuit.

208v x 20 amp breaker = 4160 watts x .90 safety factor = 3744 watts avail div 400 watt MH = 9.36 fixtures that can be hooked up to that circuit.

I guess I stand corrected. Watts are of no significance. Look it over teach ? And thank you Sparky.

Just to add if you have a 200 amp, or 600 amp service careful using up your amperage on low voltage lighting cause you may run out of SE amps for future machines, hvac or addl sub panels. That's the reason I believe lighting and machines are often 208 / 240.


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## 480sparky (Feb 1, 2009)

Let's use a plumbing analogy.

Say you want to fill up a 100-gallon tank. That 100 gallons is analogous to 100 lumens of light. It matters not whther your water pressure is 20psi (120 volts), 40 psi (240 volts) or 100 psi (480 volts), it still takes 100 gallons to fill the tank.

And you don't pay your water bill based on psi, you pay it based on the total gallons that go through the meter.

Electricity is the same way. You don't pay for voltage or amperage... you pay for watts. Kilowatt-hours, actually, which is simply 1000 watts over the course of an hour.

In order to produce 1000 watts of light over the course of an hour, the voltage nor the amperage is not relevant.


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## The Coastal Craftsman (Jun 29, 2009)

Right I understand now. Not paying for amps and voltage but paying for wattage. I see :thumbsup:


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## Tiger (Nov 21, 2007)

BCConstruction said:


> That's why I'm wondering about the wood stud walls having NM Romex installed without raceway. We are gonna be in this building for a good few years so wanna make sure its done good no matter the cost. If NM romex is fine then we won't bother and wont have the cost of the extra raceway.


EMT will serve you well in the long run. If you need additional circuits for future needs additional wiring is easily added to the conduit.


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## 480sparky (Feb 1, 2009)

See how easy electrical is? It's so easy, a 12-year old................. well, a 12-year old could do it. :laughing:


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