Some genius decided that 1" PVC was all that was needed from building to gate opener location. There is quite a bit of pavement between the two. Looking for an alternative to installing a second conduit. Could the conduit be used as a sleeve, and TC or UF pulled for the power with communication wiring alongside it?
power cable and comm in same u/g conduit?
- Thread starter Todd0x1
- Start date
- Status
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- New Jersey
- Occupation
- Journeyman Electrician
Sure.
As long as all wiring is general use and the same voltage rating it can all be together whether it is electrically sound or not. Industrial plants run shielded comm wiring with power wiring all the time. 24 VDC control in particular is almost immune to noise from AC systems.
- Location
- Bremerton, Washington
Can you quote the code section that allows running shielded comm and power wiring together?
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
It's a sleeve. You can put UF and burial rated low voltage cable in it together, no worries. Same as running NM and CAT6 in a stud bay together.
-Hal
-Hal
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Well, all rated at least as high as the highest voltage involved.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Can you cite one that prohibits it? (
Burden of proof and all that jazz.)That’s a little different. NM is both cable and raceway in one. CAT6 does not meet minimum AWG (not 18 gauge or larger) so must fall in chapter 7. The PVC is a duct bank. So technically the NM is in its own raceway separated from the outer raceway (duct bank) carrying the CAT cable. It could be just THWN but then you need to follow power limited rules (chapter 7). However a lot of control systems use #16-18 control cable using basic DC or AC signals or low speed low voltage signals like RS-485. Ethernet is generally immune to 60 Hz in the first place (1500 V of isolation, notch filter at 50-60 Hz), and the twists neutralize inductive pickup. The other types are low bandwidth and need some kind of shielding from interference or again twisted pair. As long as the cable is #18 or larger and high enough voltage insulation it can be intermixed and falls under chapter 1-3 wiring rules. No specific Code rule it’s just that it’s not a current carrying conductor as such but it’s still a conductor same as running THWN.
Now im even more confused. Can tray cable share a conduit with cat6, provided that conduit is not part of a conduit system? ie: its open on one end with the cables coming out.
Tray cable is general use. CAT 6 is not and would be chapter 7. So it is only allowed if it is power limited (chapter 7). The issue with CAT 6 is the conductors are too small for general use (#18). Does not matter if it’s armored or anything else.
In a tray if you install a divider to make it two trays, you can put them on each side of the divider but you have to maintain that split.
It’s all about the #18 minimum size (chapter 3) even though the Ethernet spec calls for 1500 V if isolation on both ends so the requirement is silly with Ethernet but NEC will not budge, especially when they allow power limited situations in chapter 7 which allows it to be run with other controls, just not major power conductors.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I agree. That answers the OP's question.
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
Sure.
Going to confuse you all even more. Type TC is a listed 600V cable. It is available in 18/2. I've proposed before that there is no reason not to use it in a raceway or conduit along with individual THHN conductors that supply line voltage to 0-10V dimming fixtures. It meets all the requirements and solves the dilemma of how to run 0-10 CL2 low voltage to fixtures installed with conduit.
Type TC just doesn't get any respect.
-Hal
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
The 2020 NEC 725.136(I)(1) now has type TC listed a one of the allowable choices. So you can do what you want if either all the power is TC or all of the CL2 is TC.Going to confuse you all even more. Type TC is a listed 600V cable. It is available in 18/2. I've proposed before that there is no reason not to use it in a raceway or conduit along with individual THHN conductors that supply line voltage to 0-10V dimming fixtures. It meets all the requirements and solves the dilemma of how to run 0-10 CL2 low voltage to fixtures installed with conduit.
Type TC just doesn't get any respect.
Providing your jurisdiction is on the 2020 cycle
- Location
- Bremerton, Washington
For the OP, you can install the power in any chapter 3 wet location wiring method with the wet locations communications wiring. As mentioned TC or UF
There is a lot of misunderstanding (including answers in this post ) of section 300 3 C 1,
(1) 1000 Volts, Nominal, or Less. Conductors of ac and dc
circuits, rated 1000 volts, nominal, or less, shall be permitted to
occupy the same equipment wiring enclosure, cable, or raceway.
All conductors shall have an insulation rating equal to at
least the maximum circuit voltage applied to any conductor
within the enclosure, cable, or raceway
What is overlooked is the IN
Informational Note No. 1: See 725.136(A) for Class 2 and
Class 3 circuit conductors.
Following the IN, the NEC says nope, you can't mix power and C2 and C3 conductors
Some of the answers here are about induction from power to comm ckts, the NEC does not care if your equipment does not work due to noise.
The reason for the separation requirement is for fire and shock prevention. If the power conductors short to comm conductors, the communications equipment is not rated to withstand the higher voltage
For example, the power and C2 wiring compartment for a gas furnace are physically separate.
There is a lot of misunderstanding (including answers in this post ) of section 300 3 C 1,
(1) 1000 Volts, Nominal, or Less. Conductors of ac and dc
circuits, rated 1000 volts, nominal, or less, shall be permitted to
occupy the same equipment wiring enclosure, cable, or raceway.
All conductors shall have an insulation rating equal to at
least the maximum circuit voltage applied to any conductor
within the enclosure, cable, or raceway
What is overlooked is the IN
Informational Note No. 1: See 725.136(A) for Class 2 and
Class 3 circuit conductors.
Following the IN, the NEC says nope, you can't mix power and C2 and C3 conductors
Some of the answers here are about induction from power to comm ckts, the NEC does not care if your equipment does not work due to noise.
The reason for the separation requirement is for fire and shock prevention. If the power conductors short to comm conductors, the communications equipment is not rated to withstand the higher voltage
For example, the power and C2 wiring compartment for a gas furnace are physically separate.
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
They just clarified it. It always was permissible if you read the fine print. Put together information from maybe three different Articles. Maybe there is some hope for the NEC when they start thinking like me.
-Hal
The TC is a cable not a conductor, so it seems that would not apply so long as the power conductors stay inside the TC jacket when. A TC for power + a cat6 in a pipe seems no different than if they were both direct buried in the same trench, or as someone else mentioned a NM and a cat6 next to each other in stud framing.
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