PHEP CH. 27

Question 1

A FUSE MAY SERVE THE SAME PURPOSE IN ISOLATING A FAULT AS A

Answer 1

CIRCUIT BREAKER

Question 2

FROM THE BELOW LIST OF FUSE CHARACTERISTICS SELECT THE ONE THAT IS NOT TRUE

Answer 2

ALL FUSES ARE COMPLETELY NON REPETITIVE IN DESIGN

Question 3

THE PRIMARY REASON FOR NOT REPLACING A BLOWN FUSE WITH A PIECE OF COPPER WIRE IS BECAUSE

Answer 3

THE DESIRED CIRCUIT PROTECTION AGAINST OVERLOAD MAY BE LOST

Question 4

THE TERM ZONES OF PROTECTION APPLIES MOST NEARLY TO THE ISOLATION OF FAULTED EQUIPMENT:

Answer 4

THROUGHOUT THE ENTIRE POWER SYSTEM

Question 5

A DEVICE BY WHICH CONTACTS IN ONE CIRCUIT ARE OPERATED BY A CHANGE IN CONDITIONS IN THE SAME OR ANOTHER CIRCUIT IS CALLED A

Answer 5

RELAY

Question 6

PROTECTIVE RELAYS IN GENERAL MUST BE ABLE TO

Answer 6

-REMOVE OR ISOLATETHE LOCAL AREA OF A FAULT FORM THE REST OF THE SYSTEM
-LOCATE FAULTS AND TRIP ONLY THOSE CIRCUIT BREAKERS DIRECTLY CONNECTED TO THE FAULTY EQUIPMENT
-DIFFERENTIATE BETWEEN PERMISSIBLE OPERATING CONDITIONS AND ABNORMAL OR FAULT CONDITIONS

Question 7

PROTECTIVE RELAYS MAY BE CLASSIFIED IN ALL OF THE BELOW WAYS EXCEPT FOR

Answer 7

ACCORDING TO THE MANNER IN WHICH THEY ARE CONNECTED IN THE CIRCUIT

Question 8

AN INDUCTION-DISK TIME OVERCURRENT RELAY

Answer 8

IS ADJUSTED SEPARATELY FOR THE DEGREE OF OVERCURRENT AT WHICH IT OPERATES AND ALSO FOR THE AMOUNT OF TIME DELAY

Question 9

DIFFERENTIAL CURRENT RELAYS ARE DESIGNED AND INSTALLED TO PROTECT AGAINST

Answer 9

INTERNAL FAULTS

Question 10

WHEN CT’S ARE USED WITH PROTECTIVE RELAYS THE DIRECTION OF CURRENT FLOW IN THE TRANSFORMER WINDINGS (POLARITY MARKS)

Answer 10

MUST BE CAREFULLY OBSERVED FOR RELAY TYPES WHICH DEPEND ON THE INTERACTION OF TWO CURRENTS FOR THEIR ACTION

Question 11

ALL OF THE FOLLOWING STATEMENTS CONCERNING THE SCHEMATIC SHOWN IN FIG. 28 ARE TRUE EXCEPT FOR

Answer 11

THE POSITION OF THE PALLET SWITCHES INDICATES THAT THE OCB IS IN A CLOSED POSITION

Question 12

A RELAY WHICH WOULD NORMALLY RESPOND TO CHANGES IN CIRCUIT ADMITTANCE, IMPEDANCE, AND REACTANCE IS CALLED A

Answer 12

DISTANCE RELAY

Question 13

POLYPHASE ROTATING EQUIPMENT MAY BE PROTECTED AGAINST SINGLE PHASE OPERATION BY USING A

Answer 13

PHASE-BALANCE RELAY

Question 14

THE PROTECTIVE DEVICE FOR A MOTOR BRANCH CIRCUIT SHOULD

Answer 14

NOT BE OF THE INSTANTANEOUS TYPE

Question 15

THE INDUCTION-DISC TIME OVERCURRENT RELAY HAS WHICH OF THE FOLLOWING CHARACTERISTICS

Answer 15

DEFINITE TIME
INVERSE TIME