1. If two phases of the supply to a three-phase induction motor are interchanged, the motor will stop.
a. True
b. False
2. The sensing network continuously monitors the motor line currents.
a. True
b. False
3. A built-in delay of five cycles prevents nuisance dropouts caused by fluctuating line voltages.
a. True
b. False
4. Motor protector modules feature phase forward.
a. True
b. False
5. Motor protector modules feature instantaneous fault protection.
a. True
b. False
Name: Class: Date:
Unit 14 Phase Failure Relays
6. One type of relay consists of a static, current-sensitive network connected ____ the line and a switching relay
connected in the coil circuit of the starter.
a. in series with b. below
c. next to d. in parallel with
7. A solid-state phase monitoring relay provides protection in the event of a(n) ____.
a. power failure b. power brownout
c. abrupt startup d. voltage unbalance
8. A solid-state phase monitoring relay provides protection in the event of a(n) ____.
a. power failure b. power brownout
c. phase reversal d. abrupt startup
9. ____ are used for the input to the motor protector module.
a. Spike suppressors b. Current transformers
c. Voltage regulators d. UPSs
Name: Class: Date:
Unit 14 Phase Failure Relays