030205e

The size of the overload device on a motor magnetic would be determined by the starting current of the motor.

True False

A three phase motor magnetic starter must have an overload heater in each phase.

True False

Magnetic overloads are made adjustable by physically moving the armature in or out of the magnetic field produced by the motor current.

True False

A standard motor magnetic consists of a contactor and an overload device.

True False

Holding contacts are connected:
A) directly in series with the stop button
B) in parallel with the operating coil
C) in series with the start button
D) in parallel with the start button
E) both "B" and "D" apply

Magnetic overloads are said to be:
A) heat dependant
B) time lag
C) instantaneous
D) none of the above

The purpose of the holding contacts on a motor magnetic is to keep the coil energized after the start button has been released.

True False

When the armature of a motor magnetic is pushed in by hand, a continuity test between terminals 2 and 3 shows zero ohms. This is an expected reading.

True False

The rule in Section 28 of the C.E.C used to determine the AMPACITY of overload heaters for motor controllers would be:
A) 28 - 304
B) 28 - 302
C) 28 - 306
D) 28 - 308

The NEMA numbering for the terminals of the holding contacts are 1 and 2.

True False

The two basic principles of operation used for overload protection devices in a motor circuit are thermal and electromagnetic.

True False

It is possible to order a bi-metal thermal overload device with ambient temperature compensation.

True False

According to the C.E.C., only two overload heaters are required for a three phase motor.

True False

"Holding" contacts are used as a by-pass of the:
A) operating coil
B) start button
C) motor contacts
D) overload heaters
E) more than one of the above apply

A motor magnetic is a:
A) relay with overload devices
B) contactor
C) contactor with overload devices
D) both "A" and "B" apply
E) all of the above apply

There are two types of thermal overload devices. These are the bi-metal and the melting alloy type.

True False

When a motor magnetic starter is used on a higher voltage the hp rating of the starter is increased.

True False

When the armature of a motor magnetic is held in the closed position, a continuity test between L(2) and T(2) indicates zero ohms. This is most likely a sign that:
A) coil needs replacing
B) everything is normal
C) the wiring in the starter is faulty
D) the contacts are faulty
E) the overload heater is burnt out

When the armature of a motor magnetic is held in the closed position, a continuity test between L(1) and T(1) indicates an open circuit. This is a sign that:
A) the wiring in the starter is faulty
B) the overload heater is burnt out
C) everything is normal
D) the contacts are faulty
E) coil needs replacing

The NEMA numbering for the terminals of the holding contacts are 2 and 3.

True False