Question 1

A starting relay is located away from the motor.

Accepted Answer

A starting relay is typically located near the capacitor or control panel, which is often away from the motor itself. Its purpose is to briefly engage the motor's startup winding to get it moving before disengaging and allowing the run winding to take over.

Question 2

The ____ operates by sensing an increase in the voltage developed in the start winding when the motor is operating.&#10;A) hot-wire relay&#10;B) current relay&#10;C) potential relay&#10;D) solid-state relay

Accepted Answer

The potential relay operates by sensing the increase in the voltage developed in the start winding when the motor is operating. This type of relay is commonly used in single-phase motor applications. A hot-wire relay senses the heat generated by the current flow and is often used as overload protection. A current relay detects current flow in the circuits and is often used in three-phase motor applications. Solid-state relays use electronic components to switch high-power circuits and provide improved reliability and speed compared to traditional electromagnetic relays.

Question 3

One disadvantage of the hot-wire relay is that it must be permitted to cool after each operation.

Accepted Answer

The hot-wire relay operates by heating a wire, which then causes it to expand and make contact with another wire. This process generates heat, and if the relay is operated too frequently without time to cool, it can overheat and fail. Therefore, it must be permitted to cool after each operation, making it a disadvantage of this type of relay.

Question 4

The ____ contains a coil of a few turns of large wire, and a set of normally open contacts.&#10;A) hot-wire relay&#10;B) current relay&#10;C) potential relay&#10;D) solid-state relay

Accepted Answer

A current relay contains a coil of a few turns of large wire, and a set of normally open contacts, which is typically used in applications like starting motors where the relay needs to sense current flow.

Question 5

The ____ is an electronic component known as a thermistor.&#10;A) hot-wire relay&#10;B) current relay&#10;C) potential relay&#10;D) solid-state relay

Accepted Answer

A thermistor is a solid-state electronic component that exhibits a change in resistance with temperature.

Question 6

The amount of voltage necessary to energize the coil of a potential relay is smaller than line voltage.

Accepted Answer

The coil of a potential relay is designed to be energized by the full line voltage, as it operates based on the voltage supplied to the system it is monitoring, typically the compressor motor in HVAC applications.

Question 7

When testing the current relay, an ohmmeter can be used to check the continuity of the contacts.

Accepted Answer

An ohmmeter can be used to test the continuity of the contacts in a current relay.

Question 8

The solid-state relay can be used to replace almost any hot-wire relay.

Accepted Answer

The answer of The solid-state relay can be used to...

Question 9

To properly test the ____, an ammeter should be used to make certain the start contact opens and disconnects the start winding.&#10;A) hot-wire relay&#10;B) current relay&#10;C) potential relay&#10;D) solid-state relay

Accepted Answer

The answer of To properly test the ____, an ammeter...

Question 10

A starting relay is used to disconnect the start windings when the motor has reached about ____ of its full speed.&#10;A) 70%&#10;B) 75%&#10;C) 80%&#10;D) 85%

Accepted Answer

A starting relay is designed to disconnect the start winding from the circuit once the motor has reached about 75% of its full speed. This is to prevent damage to the start winding and improve motor efficiency.

Deck 26: Starting Relays