150v Insulation in with 600v Insulation... Max enclosure voltage 120v

[AOGrady139]

We have a 3 gang box with 120v power and switch leg in it. The other side of the box has a 150v rated t-stat cable to control a LV card reader. Is it required to have a divider in this box since the voltage does not exceed the 150v that the t-stat insulation is rated for? Code ref. would be great!!

 

[jtinge]

300.3 Conductors
(C) Conductors of Different Systems.
(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.

Secondary wiring to electric-discharge lamps of 1000 volts
or less, if insulated for the secondary voltage involved, shall be
permitted to occupy the same luminaire, sign, or outline lighting
enclosure as the branch-circuit conductors.

Informational Note No. 1: See 725.136(A) for Class 2 and Class
3 circuit conductors.
Informational Note No. 2: See 690.4(B) for photovoltaic source
and output circuits.

Editorial comments from the Hdbk:
For systems of 1000 volts or less, the maximum circuit voltage in
the raceway is what determines the minimum voltage rating
required for the insulation of conductors, not the maximum insulation
voltage rating of the conductors in the raceway.

Informational Note No. 2 references 690.4(B), which prohibits
the location of solar photovoltaic circuits within the same
enclosure as conductors of other systems unless separated by a
partition. Additionally, 700.10(B) requires that circuit wiring for
emergency systems be kept entirely independent of all other wiring
and equipment.

 

[petersonra]

We have a 3 gang box with 120v power and switch leg in it. The other side of the box has a 150v rated t-stat cable to control a LV card reader. Is it required to have a divider in this box since the voltage does not exceed the 150v that the t-stat insulation is rated for? Code ref. would be great!!

presumably this is a class 2 circuit. i think you are probably Ok. read carefully what article 725 says about such things.

if not you can install the class 2 circuit in a raceway inside the box.

incidentally, I think you only have to maintain 1/4" of clearance between the class 2 circuit and the 120V power even if it is not in a raceway.

for raceway think carflex or something similar. or smurf tubing.

 

[iwire]

We have a 3 gang box with 120v power and switch leg in it. The other side of the box has a 150v rated t-stat cable to control a LV card reader. Is it required to have a divider in this box since the voltage does not exceed the 150v that the t-stat insulation is rated for? Code ref. would be great!!

725.136 is going to prevent running them in the same raceways regardless of the insulation.

As Bob mentioned you can bring them into the same box where required at the equipment.

 

[hbiss]

presumably this is a class 2 circuit. i think you are probably Ok. read carefully what article 725 says about such things.

if not you can install the class 2 circuit in a raceway inside the box.

Well, no you are not OK.

725.136 Separation from Electric Light,
Power, Class 1, Non–Power-Limited Fire
Alarm Circuit Conductors, and Medium-
Power Network-Powered Broadband
Communications Cables

(A) General. Cables and conductors of Class 2 and Class 3
circuits shall not be placed in any cable, cable tray, compartment,
enclosure, manhole, outlet box, device box, raceway,
or similar fitting with conductors of electric light, power,
Class 1, non–power-limited fire alarm circuits, and mediumpower
network-powered broadband communications circuits
unless permitted by 725.136(B) through (I).
Section 725.136(A) specifically includes cables of Class 2
and Class 3 circuits. Jackets of listed Class 2 and Class 3
cables do not have sufficient construction specifications to
permit them to be installed with electric light, power, Class
1, non–power-limited fire alarm circuits, and medium-power
network-powered broadband communications cables. Failure
of the cable insulation due to a fault could lead to hazardous
voltages being imposed on the Class 2 or Class 3
circuit conductors.

(B) Separated by Barriers. Class 2 and Class 3 circuits
shall be permitted to be installed together with the conductors
of electric light, power, Class 1, non–power-limited fire
alarm and medium power network-powered broadband communications
circuits where they are separated by a barrier.

(C) Raceways Within Enclosures. In enclosures, Class 2
and Class 3 circuits shall be permitted to be installed in a
raceway to separate them from Class 1, non–power-limited
fire alarm and medium-power network-powered broadband
communications circuits.

As Peter mentions, 725.136(C) allows you to run it in a raceway within the box but I don't think that's practical in your situation. Just install a divider.

-Hal

 

[JFletcher]

presumably this is a class 2 circuit. i think you are probably Ok. read carefully what article 725 says about such things.

if not you can install the class 2 circuit in a raceway inside the box.

incidentally, I think you only have to maintain 1/4" of clearance between the class 2 circuit and the 120V power even if it is not in a raceway.

for raceway think carflex or something similar. or smurf tubing.

The bolded part is in 725.136. The 1/4" is for associated systems, like the floor censor for radiant floor heat. Catx and MC into a box, you need a divider. The OP's install, I believe you need a divider since the card reader and switches for lights are not associated.