Low and high voltage in the same conduit

My advice is still: do not mix the voltage groups I mentioned above in the same conduit. I also think it is good practice to not mix 240 with 480 in the same conduit, even though it is Code legal. Our job is to create safe, efficient, Code legal installations. You can spend time trying to interpret the Code to let you do what you want, but can you convince an inspector to pass your job?

ked said:

My advice is still: do not mix the voltage groups I mentioned above in the same conduit. I also think it is good practice to not mix 240 with 480 in the same conduit, even though it is Code legal. Our job is to create safe, efficient, Code legal installations. You can spend time trying to interpret the Code to let you do what you want, but can you convince an inspector to pass your job?

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I am confused about this post.

ked said:

even though it is Code legal…… but can you convince an inspector to pass your job

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If it is code legal would not the inspector have to accept?

ked said:

You can spend time trying to interpret the Code to let you do what you want, but can you convince an inspector to pass your job?

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Yeah. I don't get your point either.
Inspectors do NOT write or make up the code. They ENFORCE it. That means no making things up as they go depending on their own moods and opinions.
They may not agree with a certain code but they have NO grounds to deny a "to-code" installation.



I spend LOTS of time interpreting the code to let me do what is CODE LEGAL and SAFE. Nothing else.

Is there any safe and effective way to run RG-6/RG-59 cable and romex wire (power cable) through the same piece of conduit. Is there some kind of device I can purchase to restore any disturbed signal? Also, what about CAT-5 and romex wire in the same piece of conduit? Finally, if I do have to run either of these in separate pieces of conduit, would it be okay to put them in the same trench?

NO, you cannot run them in the same conduit. A sleeve for protection is less clear but still not advised.

If you are talking about an underground conduit you CANNOT run romex anyway.

A couple of additional points. You can get direct burial coax. It would be safer for the cable if you put it in something. If you just bury it, make sure you bed and fill around it with something that is not full of stones and sharp pieces.

Don't use RG 59 for anything. RG 6 is much better for signal loss properties. If you are going to run phone, put it in with the coax and use cat 5. If you are going to run Ethernet, add another cat 5. You can also get direct burial phone wire.

Keep the coax as far away from the power as is convenient. A foot or two would help. The coax does not have to be as deep as code requires for power. But you don't want to dig it up by accident either.

As pointed out above, you must use individual power wires in conduit.

What about the wiring in a piece of machinery?

This turning beam will ultimately have a 480v 3-phase motor fed by a cord reel passing power on down to the hook, and we will likely use a transformer to get a little 110 for the hydraulic controls that are part of the balancing system that is pressurized by a 12-volt hydraulic pump. All considered, is it acceptable to have 12-volt DC and 110-volt AC wires running together in the pendant cord, or do we need to use contactors in a box on the beam and have a single control voltage? For fabrication and testing purposes, I presently send power up through the pendant cord.

Wow. A lot of different tangents in this old thread.

It's the voltage rating of the conductors that matters, not the voltage running through them. If all the conductors in the cable are rated for at least the highest voltage present then it is fine.

A few weeks ago, I was surprised to learn a 12v DC ground and a 120v AC ground together on the beam would not explode the hydraulic pump's supply battery!

An electrical engineer is laying out a control system to propose, and the ultimate decision about that will be made in relation to overall safety. Personally, I do not like the idea of 110 volts in the control pendant, and having two voltages there together could lead to confusion and trouble during future maintenance such as when replacing a bad switch. But, maybe all we really need to add to what we already have is the contactor for the 3-phase motor.

leejosepho said:

Personally, I do not like the idea of 110 volts in the control pendant, and having two voltages there together could lead to confusion and trouble during future maintenance such as when replacing a bad switch.

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This is why only qualified experienced people should be working on stuff like this.