Author Question: As a safety precaution, electric duct heaters should be wired so that they will not operate unless: ... (Read 44 times)

savannahhooper · **on:** Jul 24, 2018

As a safety precaution, electric duct heaters should be wired so that they will not operate unless:

A) Extra heat is needed. B) Other forms of heat are not operating.
C) The second stage of the thermostat is closed. D) The fan is operating.

Question 2

Why is there a potential of 24 V between the R terminal and the other terminals on a thermostat subbase when the thermostat is not calling?

A) Thermostats are wired with both sides of 24 V. One side is supplied to the R terminal and the other to all the remaining terminals.
B) The common side of 24 V is supplied through the coils of the devices that are not operating.
C) The meter is reading voltage that is left in the thermostat wire from the previous operating cycle.
D) Thermostats have battery backup, which can be read between R and the other terminals when the thermostat is not calling.