Exam 19: Motor Controls

Define a motor starter.

Define a relay.

Why should a technician not file the rough surfaces of a contactor's contacts?

Bimetal and solder pot overload devices are thermally operated.

What effect would a loose connection have on a solder pot overload device?

Standards for motor overload protection are set by the ____.

Why do many starters have manual resets?

When a contactor's coil is energized, how much resistance should be measured between terminal "L1" and terminal "T1"?

Why is a starter equipped with overload protection when the circuit already has a fuse or circuit breaker?

The most common material used on the surface of contacts is ____________________.

If a relay starts the indoor fan in the cooling mode of a central air-conditioning system, it must be able to withstand the ____________________  of the fan motor on start-up.

Define a pilot-duty relay.

Define a contactor.

A solder pot is part of a ____.

Contactor contacts that are badly pitted can cause the motor to burn out.

A sure sign of contact failure is discoloration on the contact surfaces.

What causes the overload of a starter to open and disable the power circuit?

The sun shining on a distribution panel has no effect on the breakers in the panel.

A common practice in condensing units is to use a contactor with only one set of contacts opening only one side of the power to the unit. This is to ____.

The best way to repair a large contactor is by the replacement of ____________________.