110.14 (C) - 75C Terminations

[Sean.Day72]

It is a VAV with heating element (not a Fan Terminal Box , FTB) just for controlling a zone off of a thermostat input. In this case, classrooms. Yes unfortunately seems there is no code I can see from the discussion where we can use #12s on a 25Amp breaker. The termination does not clearly state rated for 75C and I would not consider this a motor.

 

[dm9289]

I have a scenario where we are replacing VAV with heaters. The existing wiring is #12AWG. The kw load of the new heaters went up to 5KW @ 277 = 18Amp FLA for the new heaters. We are replacing existing 20Amp breakers with 25Amp breakers to accommodate this upsized load.
To save cost, are we able to utilize the existing #12AWG wire? I understand for loads under 100Amp to assume using the 60C ampacity table unless terminations are marked for 75C. The VAV has a label that says "Use wire suitable for at least 75C" that is not really stating the termination if rated for 75C. Has anyone ran into this? It is a lot of VAV units and could save a decent bit if existing #12AWG wire can be used vs installing new #10Awg to each new unit. Check the O&M and it does not state electrical termination temp ratings.

The Sqaure D circuit breaker is rated for 75C so good on that end of the circuit.

Keep in mind they may be asking for 75c due to heat emissions from the unit.
Is the wiring in conduit? How is it ran and what wire type.
If you look at the lugs you may see a 60/75 on them, if not assume 60c.
If you consider that 424 fixed space heating its 22.5x1.25=28
If you consider that 440 air-conditioning and refrigeration then 22.5 amps package label