can I run control wiring 24V ac to the condenser in the sane conduit with the power circuit.
All conductors are the same insulation THNN.
24v is taken from the transformer with in the unit( evaporator).
What happens when you land those wires on a standard T-stat that is probably not listed for the instance you describe.
725.130 Wiring Methods and Materials on Load Side of
the Class 2 or Class 3 Power Source. Class 2 and Class 3
circuits on the load side of the power source shall be permitted
to be installed using wiring methods and materials in
accordance with either 725.130(A) or (B).
(A) Class 1 Wiring Methods and Materials. Installation
shall be in accordance with 725.46.
Exception No. 1: The ampacity adjustment factors given
in 310.15(B)(3)(a) shall not apply.
Exception No. 2: Class 2 and Class 3 circuits shall be
permitted to be reclassified and installed as Class 1 circuits
if the Class 2 and Class 3 markings required in 725.124 are
eliminated and the entire circuit is installed using the wiring
methods and materials in accordance with Part II,
Class 1 circuits.
Informational Note: Class 2 and Class 3 circuits reclassified
and installed as Class 1 circuits are no longer Class 2
or Class 3 circuits, regardless of the continued connection
to a Class 2 or Class 3 power source.
I would rather say that the NEC tells us that the T-stat wiring may be reclassified as Class 1, but that at that point it would not be legal to connect it to a t-stat which is rated only for Class 2 or Class 3 use.Darn good question and the NEC does not tell us it is possible, only that the NEC will permit it.
I would rather say that the NEC tells us that the T-stat wiring may be reclassified as Class 1, but that at that point it would not be legal to connect it to a t-stat which is rated only for Class 2 or Class 3 use.
You could use a line voltage stat if you want, although if you have a self-contained thermocouple powered millivolt circuit for heating a line voltage stat may have too much contact resistance.
As long as the relay is not limited to Class 2 power input you should be fine.LV power (24v) for the remote condenser (relay) is coming from the evaporator and not from the thermostat. Those are the control wires that I am referring to.
those are 2 wires that I am running up to the roof and I am planning to use 2#14 THHN conductors together with the power wiring 3 Phase 208V in the same conduit.
Although there may be some inspectors who do not agree that the relay signal is "functionally related" to the unit power.
LV power (24v) for the remote condenser (relay) is coming from the evaporator and not from the thermostat. Those are the control wires that I am referring to.
those are 2 wires that I am running up to the roof and I am planning to use 2#14 THHN conductors together with the power wiring 3 Phase 208V in the same conduit.
But one of those two wires likely makes a loop through the thermostat before heading out to the condensing unit. If you "reclassify" the circuit to a class 1 circuit you must do so for the entire circuit which includes the wall thermostat, outdoor temp sensors, automatic dampers, humidifier controls, etc.LV power (24v) for the remote condenser (relay) is coming from the evaporator and not from the thermostat. Those are the control wires that I am referring to.
those are 2 wires that I am running up to the roof and I am planning to use 2#14 THHN conductors together with the power wiring 3 Phase 208V in the same conduit.
Maybe 725.48(B)(1) [2011]?And what code would they cite to bring that up? :?
The case of A/C controls with A/C power seems pretty clear, but at least one member has reported an inspector who ruled that the voltage sensing wires for a generator controller were not functionally associated with the power output wires from that generator.Maybe 725.48(B)(1) [2011]?
Just reclassifying the circuit as Class 1 by itself does not give you carte blanche to mix those Class 1 wires with power circuits.
(And, in this section, I believe power circuits include power to lighting, FWIW.)
Maybe 725.48(B)(1) [2011]?
Just reclassifying the circuit as Class 1 by itself does not give you carte blanche to mix those Class 1 wires with power circuits.
(And, in this section, I believe power circuits include power to lighting, FWIW.)