Confirmation/clarification of 300.3(C)

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
The condenser control circuit wires can be in the the same conduit that is used for the condenser circuit, as long as the control circuit wires have the voltage rating of the highest voltage between any circuit conductors. Am I correct in interpreting the code section?
 

kwired

Electron manager
Location
NE Nebraska
The condenser control circuit wires can be in the the same conduit that is used for the condenser circuit, as long as the control circuit wires have the voltage rating of the highest voltage between any circuit conductors. Am I correct in interpreting the code section?
That part is true, but that class 2 circuit also now becomes a class 1 control circuit if you run it with the power conductors. Not just a portion of the circuit, the entire control circuit is now a class 1 control circuit. Your class 2 wiring to the thermostat as well as the thermostat itself now need to be class 1 rated and any other components that may be connected to this control system.

See art 725.136 (2017 NEC)
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
The condenser control circuit wires can be in the the same conduit that is used for the condenser circuit, as long as the control circuit wires have the voltage rating of the highest voltage between any circuit conductors. Am I correct in interpreting the code section?
Short answer in general, no. Look at one of the reasons in kwired's post.
 

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
That part is true, but that class 2 circuit also now becomes a class 1 control circuit if you run it with the power conductors. Not just a portion of the circuit, the entire control circuit is now a class 1 control circuit. Your class 2 wiring to the thermostat as well as the thermostat itself now need to be class 1 rated and any other components that may be connected to this control system.

See art 725.136 (2017 NEC)
Ohh I see.

Yes and no.
See the IN for that section
I followed the IN but I see what KWired said.

Thanks you Gentlemen.
 
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