different voltages

[mannyb]

We are installing a Mitsubishi split system HAVC 2 condensers on roof with limited roof penetration for conduit. i want to run 1 conduit to each unit But a 3 wire needs to return to VFD blower in room. The HVAC people say its LV which means IDK til I see it tomorrow BUt In regards to which of these classes will this type of install will this fall into as class 1 2 or 3 wiring. which of these can run in same conduit with AC power cable? can 24v run with 240v as long as same installation type? I am pretty sure class 1 wiring can but not so sure class 2 or 3 to be honest I have no freakin idea. i want to go into this with a little fore knowledge. Thanks for any help

 

[Dennis Alwon]

I think this is the section you need. Art. 300.3

(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.

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
medium-power network-powered broadband communications
circuits unless permitted by 725.136(B) through (I).
(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.

 

[mannyb]

I think this is the section you need. Art. 300.3

my first thing will be to establish voltage from condenser to blower. i understand its a VFD that controls blower. if Im still working with same voltage i am in the clear. if not i will need to try to fit one extra conduit for LV wiring or class 2 or 3.

BTW Could i install the 120v gfci requirement for HVAC unit outlet in same conduit thru disconnect to a bell box to meet receptalce outlet requirement?