15

Question 1

What does the energy saver switch do?

Answer 1

Saves energy so power isn’t always running to the load

Question 2

What functions do the batteries of an electronic/digital thermostat accomplish?

Answer 2

Illuminates the display during a power outage.
Retains the settings in memory during a power outage.
Acts as the “C” terminal if the “C” wire is not connected to the subbase.

Question 3

If an air conditioning system is calling for cooling and the compressor and condenser fan are running but the indoor evaporator fan motor is not running, which terminal on the thermostat will the technician most likely check first?

Answer 3

G

Question 4

a circuit has a current draw of O amps, is the load energized?

Answer 4

Load isn’t energized

Question 5

voltage is being supplied to a load and the load is not operating, what can be said about the switches in the circuit?

Answer 5

The switches are closed and fine, something wrong with load.

Question 6

Customer says that the thermostat is set to 75°F. It’s been running for the past 2 hours and the current temperature is only 73°F. Normally it only takes 30 minutes to make temperature before Shutting off. The system uses a 24V control circuit and the high voltage side of the circuit is 230V.
You suspect that the 2d stage is not being energized causing the 1st stage to heat the entire home, thus taking longer for it to reach the cut-out temperature set point.

T/F the transformer is not working

Answer 6

F

Question 7

Customer says that the thermostat is set to 75°F. It’s been running for the past 2 hours and the current temperature is only 73°F. Normally it only takes 30 minutes to make temperature before Shutting off. The system uses a 24V control circuit and the high voltage side of the circuit is 230V.
You suspect that the 2d stage is not being energized causing the 1st stage to heat the entire home, thus taking longer for it to reach the cut-out temperature set point.

Meter set to volts, thermostat removed from subbase and probes placed on subbase terminals R & W2 shows 24V. You conclude that

Answer 7

Jump R to W2 but 2’’ stage heat elements do not energize

Question 8

Customer says that the thermostat is set to 75°F. It’s been running for the past 2 hours and the current temperature is only 73°F. Normally it only takes 30 minutes to make temperature before Shutting off. The system uses a 24V control circuit and the high voltage side of the circuit is 230V.
You suspect that the 2d stage is not being energized causing the 1st stage to heat the entire home, thus taking longer for it to reach the cut-out temperature set point.

Replace thermostat on subbase and call for heat. Go to air handler and check to see if power is reaching the 2’d stage heater contacts on both the control and high voltage lines.
Set meter to volts and check across the 2K coil and contacts 2K1 & 2K2. Your expected meter readings

Answer 8

Coil 24V, Contact 1 & 4 230V