Chapter 24 refrigeration cycle controls Book 2

Question 1

Bimetallic thermostat

Answer 1

Substituted similar metals that are bonded together, each with a different coefficient of expansion. The bending action can be used to close or open electrical circuit that starts or stops or compressor. If it’s a small compressor, the thermostat may control it directly larger motors with high current draw or indirectly controlled by the thermostat that actuates a magnetic motor starter or a contactor

Question 2

Compressor control by expansion of a fluid or gas

Answer 2

A bulb tube, and and or bellows is filled with a liquid gas or saturated mixture of the two as the temperature increases. The pressure in the bulb, increases and pushes against a beam, moving it to the left as the electrical contactor approaches of the station area contact the armature will snap shut to a magnet that is stationary the Contacts remain closed until the spring force overcomes the force of the magnet when the temperature decreases and the Bellows pressure decreases

Question 3

Low oil, sump, temperature protection device prevents the compressor from starting if the oil temperature falls below a preset value so that?

Answer 3

Any refrigerant, dissolved in the oil is separated from the lubricant

Question 4

Thermostatic refrigeration, controller has a differential adjustment that sets the temperature at which the?

Answer 4

Cut in and cut out occurs

Question 5

The pressure actuated refrigeration control is actuated by the

Answer 5

Suction pressure of the compressor