620

[hhsting]

I dont understand. NEC 2017 section 620.53 calls for elevator car light, receptacles, and ventilation disconnect. However NEC 2017 section 620.54 calls again for elevator heating and air-conditioning disconnect.

I dont understand I thought ventilation is the same as hvac. Why then two different disconnect? What is the difference between the two?

 

[don_resqcapt19]

They are not the same... ventilation just moves air, heating and air conditioning equipment changes the temperature of the air.
HVAC includes all, but the code does not say HVAC, it has one rule for ventilation and a second rule for heating and air conditioning.