Technician A says that some of the plates used in a multiple-disc clutch are lined with paper friction material.
Technician B says that some of the plates used in a multiple-disc clutch are unlined steel plates.
Which technician is correct?

Technician A

Explanation:

In the case of multiple-disc clutches, composite paper materials are very common. Since these multiple-disc clutches typically use an oil bath or flow-through cooling method for keeping the disc pack lubricated and cooled, very little wear is seen when using composite paper materials.

Step 1

Check the thermostat temperatures. There are two temperatures to take into consideration when dealing with a thermostat; set point temperature and room temperature. Set point is your desired temperature and room temperature is your surrounding space temperature. Therefore heating equipment will be running when your set point is above room temperature and cooling equipment will be running when your set point is below room temperature. If the room temperature seems off, check it against another thermometer. A digital thermostat can usually be calibrated. Mercury thermostats cannot be calibrated, but need to be level in order to work correctly.

Step 2

Calibrate your room temperature. If the room temperature seems off, check it against another thermometer. A digital thermostat can usually be calibrated. A user's manual will be necessary to do this, every thermostat is different. Mercury thermostats cannot be calibrated, but need to be level in order to work correctly.

Step 3

Check the connections. Remove the cover off the thermostat. You will expose the thermostat wire connections. R, W, Y, G, C are the most common connections. R is 24-volt power, W is heat, Y is cooling, G is fan, and C is the common side of the 24 volts. If there is no wire to C the thermostat is battery powered. Depending on how the thermostat is set, R will internally connect to W, Y, or G telling the corresponding equipment to come on. Make sure all connections have good contact and are tight.

Step 4

Take the thermostat out of the equation. To take the thermostat out of the equation you will need to need to do what the thermostat does internally. Shut off power to furnace. Once the power is off, label and remove the wires from the thermostat. Remember, all that the thermostat does is to connect R to W, Y, or G. So twist the R and W wire ends together, turn power back on and the furnace should come on. Check R to Y and R to G and make sure the cooling and fan come too. If all your equipment is coming on during direct wiring like this, and it wasn't coming on when hooked up to the thermostat, then your thermostat was the problem.

Explanation: