Power and low voltage same raceway

[mstrlucky74]

Have an application where a # 18 cable to control ballast and #12 for power has to go to each light. Problem is we want to run it in the deck with these cables under one PVC jacket( cable) and NYC amended the code not allowing low and line voltage in the same raceway. Any ideas how to still do this efficiently in the deck? Thanks

 

[GoldDigger]

Have an application where a # 18 cable to control ballast and #12 for power has to go to each light. Problem is we want to run it in the deck with these cables under one PVC jacket( cable) and NYC amended the code not allowing low and line voltage in the same raceway. Any ideas how to still do this efficiently in the deck? Thanks

Does the NYC amendment still apply when the low voltage conductors are insulated for the higher voltage? That configuration was specifically allowed under NEC. Also no NYC exception for low voltage wires associated with the operation of the same equipment that the high voltage wires are feeding?

If you are only using an outdoor-rated cable assembly in a protective sheath, there is no "raceway" for them to share. A cable, by itself, is IMHO not a raceway.
Of course the point where you break the wires out of the cable to go to high and low voltage terminals might still be considered part of one raceway, I suppose. Either that or part of a single listed control assembly, without an intervening raceway?

How are the wires terminated at each light/luminaire? Is there even any provision for attaching two separate raceways there?

 

[mstrlucky74]

Does the NYC amendment still apply when the low voltage conductors are insulated for the higher voltage? That configuration was specifically allowed under NEC. Also no NYC exception for low voltage wires associated with the operation of the same equipment that the high voltage wires are feeding?

If you are only using an outdoor-rated cable assembly in a protective sheath, there is no "raceway" for them to share. A cable, by itself, is IMHO not a raceway.
Of course the point where you break the wires out of the cable to go to high and low voltage terminals might still be considered part of one raceway, I suppose. Either that or part of a single listed control assembly, without an intervening raceway?

How are the wires terminated at each light/luminaire? Is there even any provision for attaching two separate raceways there?

I believe it does apply when LV conductors are insulated for the higher voltage. No sure about the association of LV cables operating same equip as HV, will check. Good point about the raceway. So a pvc coated mc cable you would not consider a raceway? You lost me in your paragraph where the wires breakout of the cable assembly.
THe LV wires terminate on an Lutron Ecosystem ballast and the 120v wires terminate....hmm thata a good question. The detail surely shows the LV & HV cables going to light fixture and those who have looked into this understand that.

Thanks.

 

[GoldDigger]

I believe it does apply when LV conductors are insulated for the higher voltage. No sure about the association of LV cables operating same equip as HV, will check. Good point about the raceway. So a pvc coated mc cable you would not consider a raceway? You lost me in your paragraph where the wires breakout of the cable assembly.
THe LV wires terminate on an Lutron Ecosystem ballast and the 120v wires terminate....hmm thata a good question. The detail surely shows the LV & HV cables going to light fixture and those who have looked into this understand that.

Thanks.

2011 NEC, Article 100 Definitions:

Raceway. An enclosed channel of metal or nonmetallic materials designed expressly for holding wires, cables, or busbars, with additional functions as permitted in this Code. Raceways include, but are not limited to, rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, liquidtight flexible conduit, flexible metallic tubing, flexible metal conduit, electrical nonmetallic tubing, electrical metallic tubing, underfloor raceways, cellular concrete floor raceways, cellular metal floor raceways, surface raceways, wireways, and busways.

Cable is not defined, but if conductors cannot be removed from or added to the inside of the protective covering of a cable, that protective covering would not constitute a raceway. (NEC does not allow you to assemble raceways with the conductors already inside them. You have to pull them in after assembly. Except for something that is an integral part of listed equipment.)

 

[don_resqcapt19]

The voltage is not the real factor in the NEC rules for control wires in the same raceway or cable as the power wires. The Class of the power supply for the control wires is the major factor.
It appears the control wire for that ballast can be either Class 1 or Class 2. Class 1 conductors are permitted to be installed with the power conductors as long as they have insulation rated for the highest voltage that any of the associated conductors is carrying. In general Class 2 circuit conductors cannot be installed with power conductors.

 

[mstrlucky74]

2011 NEC, Article 100 Definitions:



Cable is not defined, but if conductors cannot be removed from or added to the inside of the protective covering of a cable, that protective covering would not constitute a raceway. (NEC does not allow you to assemble raceways with the conductors already inside them. You have to pull them in after assembly. Except for something that is an integral part of listed equipment.)

Great explanation...thanks.

 

[mstrlucky74]

The voltage is not the real factor in the NEC rules for control wires in the same raceway or cable as the power wires. The Class of the power supply for the control wires is the major factor.
It appears the control wire for that ballast can be either Class 1 or Class 2. Class 1 conductors are permitted to be installed with the power conductors as long as they have insulation rated for the highest voltage that any of the associated conductors is carrying. In general Class 2 circuit conductors cannot be installed with power conductors.

Thanks. So how exactly do you determine whether a wire is class 1 or 2? The power supply gives that info? I have been trying the find the cose section that explains Class 1&2 wire in the same raceways as power wires.....which section?THanks

EDIT: Is it 725.48? Thanks.

 

[GoldDigger]

The voltage is not the real factor in the NEC rules for control wires in the same raceway or cable as the power wires. The Class of the power supply for the control wires is the major factor.
It appears the control wire for that ballast can be either Class 1 or Class 2. Class 1 conductors are permitted to be installed with the power conductors as long as they have insulation rated for the highest voltage that any of the associated conductors is carrying. In general Class 2 circuit conductors cannot be installed with power conductors.

My second question is just what the NYC amendment actually says, if this is not just the applicable NEC cycle's restrictions being applied.

 

[hurk27]

Also beyond what the code requires, their may be problems caused by capacitive coupling of the higher voltage current to the low voltage control wires which may or may not affect the operation of the light controls, you might want to check with the manufacture to see if this could be a problem, I saw this problem first hand on a Leviton remote motion detector where the installer had ran the LV conductors from the relay within the same conduit that the HV conductors ran in, it kept the lights on even hours after anyone triggered the motion detector, once the motion detector pulled the relay in the phantom voltage was just enough to keep it pulled in, ran a 18/3 class 2 cable between the relay and MD and it worked just fine.

 

[don_resqcapt19]

Thanks. So how exactly do you determine whether a wire is class 1 or 2? The power supply gives that info? I have been trying the find the cose section that explains Class 1&2 wire in the same raceways as power wires.....which section?THanks

EDIT: Is it 725.48? Thanks.

For Class 2 and 3 conductors the rule in is 725.136(A).

Class 2 or 3 power supplies are so marked. The voltage and current limits for those power supplies are found in Chapter 9, Tables 11A and 11B.

 

[infinity]

The voltage is not the real factor in the NEC rules for control wires in the same raceway or cable as the power wires. The Class of the power supply for the control wires is the major factor.
It appears the control wire for that ballast can be either Class 1 or Class 2. Class 1 conductors are permitted to be installed with the power conductors as long as they have insulation rated for the highest voltage that any of the associated conductors is carrying. In general Class 2 circuit conductors cannot be installed with power conductors.

I agree and these Lutron ballasts are designed for either class 1 or class 2 operation. We have installed thousands of fixtures with these type of ballasts with power and control conductors together using THHN for both in a common raceway or cable.

Also there is no NYC amendment to 725.136(A).

 

[mstrlucky74]

I agree and these Lutron ballasts are designed for either class 1 or class 2 operation. We have installed thousands of fixtures with these type of ballasts with power and control conductors together using THHN for both in a common raceway or cable.

Also there is no NYC amendment to 725.136(A).

Thanks Infinity. But as stated earlier class 2 can't be combined wih power but class 1 can so when you say you have done this thousands of times is that with class 1 wiring? You use a thhn cable for control to these lutron ballasts? What size? Since you seem to be very familiar with this application what would suggestion for these power and control cables to be run in the deck? Pvc coated mc? Thanks

 

[kwired]

Thanks Infinity. But as stated earlier class 2 can't be combined wih power but class 1 can so when you say you have done this thousands of times is that with class 1 wiring? You use a thhn cable for control to these lutron ballasts? What size? Since you seem to be very familiar with this application what would suggestion for these power and control cables to be run in the deck? Pvc coated mc? Thanks

Basically you follow part II of art 725 instead of part III. Class 1 conductors can be run with lighting and power conductors if they are functionally associated, insulation of conductors must be rated for highest voltage in the raceway or cable and all of the circuit must be treated as class 1. You can not run part of the circuit as class 1 and part of it as class 2, even though the equipment is designed to be used for either case.

 

[mstrlucky74]

Basically you follow part II of art 725 instead of part III. Class 1 conductors can be run with lighting and power conductors if they are functionally associated, insulation of conductors must be rated for highest voltage in the raceway or cable and all of the circuit must be treated as class 1. You can not run part of the circuit as class 1 and part of it as class 2, even though the equipment is designed to be used for either case.

Thanks for the info. What if the lv wires for the Lutron ballast control are class 2? Thats what i wanted ininity to answer because he said he has done it many times. Thanks again

 

[GoldDigger]

Thanks for the info. What if the lv wires for the Lutron ballast control are class 2? Thats what i wanted ininity to answer because he said he has done it many times. Thanks again

don_resqcapt19 has indicated that the Lutron specification allows connecting the ballast's control leads using either class 1 or class 2 wiring. I would assume that the same dual rating is applicable to the control end. Check the specifications....

 

[mstrlucky74]

don_resqcapt19 has indicated that the Lutron specification allows connecting the ballast's control leads using either class 1 or class 2 wiring. I would assume that the same dual rating is applicable to the control end. Check the specifications....

Thanks G!!!

 

[infinity]

If you look though the Lutron literature you will see that their eco ballasts are listed for class 1 or class 2 operation.

As far as MC goes, if I remember correctly you would need a 5 conductor cable (there are many different applications and wiring schemes so you need to check with Lutron for the conductor size/number for the specific Lutron ballasts). The two class one conductors can be #18 if the distance isn't too great.

Depending on how much deck MC cable you would need it may be cost effective to have someone like Southwire make the cable for you. In the past I have seen some contractors use off the shelf MC and re-identify the control conductors which can turn into a big mess.

 

[mstrlucky74]

If you look though the Lutron literature you will see that their eco ballasts are listed for class 1 or class 2 operation.

As far as MC goes, if I remember correctly you would need a 5 conductor cable (there are many different applications and wiring schemes so you need to check with Lutron for the conductor size/number for the specific Lutron ballasts). The two class one conductors can be #18 if the distance isn't too great.

Depending on how much deck MC cable you would need it may be cost effective to have someone like Southwire make the cable for you. In the past I have seen some contractors use off the shelf MC and re-identify the control conductors which can turn into a big mess.

Threy are calling for #16's for the control.

 

[mstrlucky74]

If you look though the Lutron literature you will see that their eco ballasts are listed for class 1 or class 2 operation.

As far as MC goes, if I remember correctly you would need a 5 conductor cable (there are many different applications and wiring schemes so you need to check with Lutron for the conductor size/number for the specific Lutron ballasts). The two class one conductors can be #18 if the distance isn't too great.

Depending on how much deck MC cable you would need it may be cost effective to have someone like Southwire make the cable for you. In the past I have seen some contractors use off the shelf MC and re-identify the control conductors which can turn into a big mess.

Can control conductor have thhn insualtion?

 

[kwired]

Can control conductor have thhn insualtion?

Sure they can. Insulation type used is determined by conditions it will be exposed to and not what type of load is being supplied.