Reversing Motor Chapter 15

power

Troubleshooting reversing ___ circuits normally involves determining the point in the system where power is lost.

crossing dashed

___ lines are used between the manual starters in a wiring diagram to indicate a mechanical interlock.

Limit

___ switches may be used to provide automatic control of reversing circuits.

Running

___ windings are made of a heavier gauge wire than starting windings, so they have a much lower resistance than starting windings.

jogging

A ___ circuit allows the operator to start a motor for short times without memory.

control

A ___ circuit does not operate when the overloads are tripped.

wiring

A ___ diagram is used to locate the actual test points at which a DBM is connected to the circuit.

pushbutton

A ___ interlock is normally factory-installed by the manufacturer.

line diagram

A ___ is used to illustrate circuit logic.

manual

A ___ starter is a contactor with an added overload protecttive device.

selector

A ___ switch and a basic start/stop station can be used to reverse a motor.

leads

A drum switch is used only as a means of controlling the direction of a motor by switching the ___ of the motor.

interlock

A mechanical ___ is the arrangement of contacts in such a way that both sets of contacts cannot be closed at the same time.

L3

Although any two lines may be interchanged to reverse a 3 phase motor, the industry standard is to interchange L1 and ___.

electrical

Although most magnetic reversing starters provide mechanical interlock protection, some circuits are provided with a secondary backup or safety backup system that uses auxiliary contacts to provide ___ interlocking.

transformer

Although the power circuit and control circuit operate together to control a motor, they are electrically isolated from each other through a ___.

wiring diagram

Always consult the manufacturer ___ to ensure proper wiring.

protective overloads

Drum switch are not motor starters because they do not contain ___.

insulated handle

Drum switch are totally enclosed and a ___ provides the means for moving the contacts from point to point.

jumpers

If several connections of a given number are required, ___ can be added to the terminal strip to provide multiple connection points to one given terminal number.

F2

In a DC shunt motor, regardless of whether the forward contacts or reverse contacts are closed, ___ is always positive.

point-to-point

In direct hardwiring, the power circuit and the control circuit are wired ___.

armature

Reversal of a DC compound motor is accomplished by reversing the ___ connections.

running

Reversing the rotation of 1 phase motors is accomplished by interchanging the leads of the starting or ___ windings.

control

The ___ circuit includes the required circuit inputs (pushbutton, limit switches, etc.) motor starter coils, motor starter auxiliary contacts, overload contacts, timers, and, counters.

fields

The direction of rotation may be reversed in a DC motor by reversing the direction of the current through the armature without changing the direction of the current through the ___.

direct hardwired

The disadvantage of a ___ circuit is that circuit troubleshooting and circuit modification are time consuming.

stops

To reverse a running motor using a drum switch, the handle must first be moved to the center position until the motor ___ and then moved to the reverse position.

Point-to-point

wiring is wiring in which each component in a circuit is connected (wired) directly to the next component as specified on the wiring and line diagrams.