Question

Name two methods used in hermetic compressor motors to take the start winding out of the circuit when the motor is up to speed.

Answer 1

Two methods used in hermetic compressor motors to take the start winding out of the circuit when the motor is up to speed are centrifugal switches and start relays.

Step-by-step explanation:

In hermetic compressor motors, there are two methods commonly used to take the start winding out of the circuit when the motor is up to speed. One method is the use of centrifugal switches, which are mechanical switches that are actuated by the centrifugal force generated as the motor spins. When the motor reaches a certain speed, the centrifugal force pushes the switch contacts open, effectively removing the start winding from the circuit.

The second method is the use of a start relay. A start relay is an electromagnetic device that controls the switching of the start winding. When the motor is first turned on, the start relay closes the switch contacts, allowing current to flow through the start winding. Once the motor reaches the desired speed, the start relay opens the switch contacts, disconnecting the start winding from the circuit.

Answer 2

Hermetic compressor motors commonly use centrifugal switches or solid-state relays to remove the start winding from the circuit when up to speed.

Step-by-step explanation:

In hermetic compressor motors, two common methods used to disengage the start winding when the motor reaches operating speed are centrifugal switches and solid-state relays. The centrifugal switch is a mechanical device that operates based on the rotational speed of the motor. As the motor spins up to speed, centrifugal force causes weights to move outward, triggering the switch to open and disconnect the start winding from the circuit. On the other hand, solid-state relays rely on electrical characteristics such as back electromotive force (EMF), which increases as the motor speeds up. When the back EMF reaches a certain threshold, it signals the relay to remove the start winding from the circuit, ensuring efficient operation of the compressor motor.