How to connect recessed lights to existing EMT pipes

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  #1  
Old 10-15-11, 07:11 AM
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How to connect recessed lights to existing EMT pipes

I have a situation where EMT conduits were directly piped to a series of recessed lights. Meaning, they mount the lights to the joists first, then they hard piped the EMT conduits to the little junction box. From that junction box, they pipe to the next. So except for the first and last, each of the light's junction box has two pipes connecting to it.

I am going to remove all these lights because they are 40 years old and corroded, and beat up during demolition. They are the expensive Lightolier ones with no current parts available anyways.

My question is, since the junction box is actually part of the housing assembly, if I remove the light, I will have a pipe with conductors coming off it. If I mount a new light, I am sure it's junction box will be somewhere else close by but not exactly there.

What is the best way to handle this?

(A) Connect a handy box to the existing conduit. Then mount new housing. Use a NM or MC cable to go from handy box to new light junction box.

(B) Mount new housings where you want them, then bend new EMT conduit from the end point to the new housing box.

(C) Cut the pipe back a foot or so, and install a proper 1900 box somewhere mounted to the rafter or joist. Then mount new light and connect with NM or MC cables.

(D) Only keep the pipe to the first light in series. Mount a junction box there. Remove ALL downstream intermediate pipes and go with all NM or MC cables.

These lights are about ten to twelve feet apart, along one wall then another. Six in series.
 
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Old 10-15-11, 07:30 AM
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I would leave the pipe coming up from the switch but remove all the conduit and housings. I would replace it with new NM-B.

The amount of time to rework the old conduits and still need to install 90 degree C rated conductors just isn't worth it time-wise.
 
  #3  
Old 10-15-11, 11:15 AM
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I guess there is yet another option. Which is to leave everything in place except the actual can and cable. In other words, the can is connected to the box with an MC cable, I can disconnect the MC cable and leave the old box alone, and for the new lights, remove the cable from the junction box of the new housing, and connect the cable to the old box instead. That work work if the old box is close enough and the new box will just be abandoned.

Hmmm...no, too much trouble. Never mind.

I think I will just rewire all.

Any thoughts as to using NM-b versus MC cables to jump from light to light? Cost wise it is about the same.
 
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Old 10-15-11, 11:36 AM
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I would use the MC cable. Your house was wired with EMT/MC, why downgrade to romex.
 
  #5  
Old 10-15-11, 11:44 AM
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Originally Posted by Justin Smith View Post
I would use the MC cable. Your house was wired with EMT/MC, why downgrade to romex.
Why do you consider NM-b a downgrade. NM-b is a fully approved wiring system. Just because something is harder doesn't make it better.
 
  #6  
Old 10-15-11, 06:54 PM
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Cost wise, MC cables and NM-b are about the same where I live anyways.

I really don't know if MC is better or worse then NM-b. I prefer EMT because it is easier to run more wires or route wires without getting up into the attic. I did realize after a while the problem with EMT is not the conduits, but the tendency to share neutrals between circuits, it's too easy to do so and then it is difficult to know which neutral goes with which when you are dealing with three pigtails with 10 white wires. With NM-b I guess you always have them together and the neutral is more likely to be dedicated, is that correct?

I found MC cables to be more rigid and easier to see in the attic (I can always run a flash light from the attic hatch and see where the MC cable goes to) but with NM-b I have to actually trace it since it tends to settle into or under the insulation.

Are there other advantages and disadvantages of MC vs NM-b, if cost is not a consideration?
 
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Old 10-15-11, 07:26 PM
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I think the big difference is NM cables are easier to work with and romex connectors are considerably cheaper than MC connectors. As far as price, 12-2 solid MC is about 6 cents a foot higher than 12-2 NM, 12-2 stranded MC would be about 15 or 16 cents a foot higher. NM cables typically only require a few staples in the attic where MC cables are typically secured with one hole straps such as a Jiffy 125. I'd go with the NM cable in a residential application.
 
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Old 10-15-11, 07:36 PM
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MC also uses an aluminum jacket and an insulated ground.
 
  #9  
Old 10-16-11, 06:27 AM
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Originally Posted by Justin Smith View Post
MC also uses an aluminum jacket and an insulated ground.
MC is commonly available with a steel jacket and also commonly available without an insulated ground, but I don't think these are differences the OP is looking for. OR...maybe they are.
 
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