6. Molded case circuit breakers

ALL OTHER CIRCUIT BREAKERS USED FOR DISTRIBUTION AND LOAD-CIRCUIT PROTECTION PURPOSES ARE MOLDED CASE CIRCUIT BREAKERS. THESS BREAKERS ARE AUTOMATICALLY TRIPPED. SHOULD AN OVERLOAD OR SHORT CIRCUIT DEVELOP IN THEIR LOAD CIRCUITS, THE REESTABLISHMENT OF CONNECTION CAN BE MADE EASILY AND SAFELY WITHOUT NEED FOR REPLACEMENT OF ELEMENTS SUCH AS FUSES,

FOR CONSTRUCTION AND OPERATIONAL DETAILS, REFER TO THE RELEVANT MOLDED CASE CIRCUIT BREAKER MANUALS.

Chapter 2

STARTING AND STOPPING OF ENGINE GENERATOR SETS

1. Summary

MSBD : THE MAIN SWITCHBOARD( MSB ) NORMALLY RECEIVES ELECTRIC POWER FROM ONE TO THREE DIESEL GENERATORS ON BOARD, WHICH CAN BE PARALLELED TOGETHER ON THE MSB BUS : START-STOP CONTROL OF THE DIESEL GENERATOR IS POSSIBLE FROM MSB.

ESBD : THE EMERGENCY SWITCHBOARD( ESBD ), FROM ITS NATURE, IS

INTENDED FOR FULLY AUTOMATIC OPERATION, THEREFORE MANUAL OPERATIONS DESCRIBED IN THIS SECTION ARE PRIMARILY FOR INSPECTION AND MAINTENANCE PURPOSES AS WELL AS GIVING A GENERAL IDEA WHAT CAN BE DONE IN THE EVENT OF AN AUTOMATIC DEVICE OR CIRCUIT FAILURE.

2. Manual start-stop control of diesel engines

MSBD : THE DIESEL ENGINES CAN BE CONTROLLED EITHER FROM SYNCHRO PANEL OR FROM THE GENERATOR ENGINE CONTROL PANEL(GECP /LOCAL) LOCATED IN GENERATOR SPACE.

THE "ENG CONTROL" SWITCH ON GECP/LOCAL GIVES A CHOICE OF CONTROL POSITION ; LOCAL POSITION PLACES GECP/LOCAL IN CONTROL AND REMOTE POSITION TRANSFERS CONTROL TO MAIN SWITCHBOARD.

ESBD : MANUAL START-STOP CONTROL OF THE DIESEL ENGINE DRIVING THE EMERGENCY GENERATOR IS POSSIBLE ONLY FROM THE MACHINE SIDE. FOR STARTING AND STOPPING OF DIESEL ENGINE, REFER TO THE ENGINE MANUFACTURER'S INSTRUCTION MANUAL,

2-1. CONTROL FROM MAIN SWITCHBOARD

EACH DIESEL ENGINE IS READY FOR CONTROL FROM MSB WHEN ALL OF THE FOLLOWING CONDITIONS ARE MET :

1) DC24V POWER IS SUPPLIED TO THE CONTROL CIRCUIT.

2) THE TURNING BAR IS STORED IN THE SPECIFIED POSITION.

3) THE STARTING AIR VALVE IS OPOEN,

4) THE HANDLE SWITCH IS POSITIONED TO RUN,

5) "ENG CONTROL" SWITCH ON GECP/LOCAL IS SELECTED TO REMOTE.

6) EACH ENGINE ABNORMAL STOP ALARMS ARE RESET(ALARM LAMPS ARE PROVIDED ON GECP/LOACL).

FULFILLMENT OF THE ABOVE CONDITIONS IS INDENTIFIED BY LIGHTING OF "REMOTE CONTROL POSSIBLE" LAMP ON SYNCHRO PANEL.

A. START

WITH "REMOTE CONTROL POSSIBLE" LAMP LIGHTED, POSITION "ENG CONTROL" SWITCH ON SYNCHRO PANEL TO START : THE ENGINE STARTS,

IF THE ENGINE DOES NOT REACH 300rpm ABOVE WITHIN 15 SECONDS "ENG CONTROL" SWITCH OPERATION, IT WILL BE ALARMED ON GECP/LOCAL AS START FAILURE.

B. STOP

PUSHING THE ENGINE STOP PUSH BUTTON AFTER THE GENERATOR IS DISCONNECTED FROM THE MSB BUS.

3. Manual generator control procedure for msbd

3-1. INITIAL CHECK-OUT

A. SHORE POWER RELAY(52XS) SHOULD NOT BE ENERGIZED.

B. THE VOLTAGE REGULATOR CONTROL(VR) IS IN THE SPECIFIED POSITION, VR IS IN THE GENERATOR PANEL AND ADJUSTS VOLTAGE MANUALLY, FOR DETAILS, REFER TO THE GENERATOR MANU¬FACTURER'S MANUAL.

3-2. PLACING A GENERATOR ONTO A DEAD BUS

THE FOLLOWING DESCRIBES, AS AN EXAMPLE, HOW TO PUT NO.l ONTO A DEAD BUS.

A. ENGINE START

WITH "REMOTE CONTROL POSSIBLE" LAMP FOR D/Gl TURNED ON, PUSH THE START PUSH BUTTON SWITCH TO START.

B. VOLTAGE ESTABLISHMENT

AS THE ENGINE APPROACHES THE SYNCHRONOUS SPEED, THE GENERATOR VOLTAGE BUILDS UP TO ITS RATED VOLTAGE AND "GEN RUN" LAMP BECOME ON AND BRIGHTER,

C. VOLTAGE AND FREQUENCY CHECK AND ADJUSTMENT

CHECK THE GENERATOR VOLTAGE AND FREQUENCY(NO.l) BY THE VOLTMETER AND FREQUENCY METER ON THE GENERATOR AND SYNCHRO PANEL, SELECTING "VOLTMETER" SWITCH TO EACH PHASE TO PHASE POSITION, IF OTHER THAN 450V AC, ADJUST THE GENERATOR VOLTAGE TO 450V AC WITH VR, FOR DETAILS ON THESE

ADJUSTMENTS, SEE THE GENERATOR MANUFACTURER'S MANUAL. IF OTHER THAN 60HZ, OPERATED 'GOVERNOR MOTOR" SWITCH TO LOW IF HIGHER THAN 60HZ, OR THE RAISE IF LOWER THAN 60HZ, AND ADJUST THE FREQUENCY TO 60HZ.

D. LOAD CONNECTION

AFTER CHECKING THAT ALL GENERATOR ACBS AND THE SHORE CONNECTION BREAKER ARE TURNED OFF, OPERATE "ACB CONTROL" SWITCH FOR NO. 1 TO CLOSE THE NO, 1 GENERATOR'S ACB, CHECK THE GENERATOR VOLTAGE AGAIN, THEN TURN ON THE NECESSARY FEEDER AND LOAD CIRCUIT BREAKERS.

3-3. PLACING A GENERATOR ONTO A LIVE BUS(GENERATOR PARALLELING)

A. GENERATOR REQUIREMENTS

IN ORDER TO PUT A GENERATOR ONTO A LIVE BUS ALREADY SERVED BY OTHER GENERATOR, THE FOLLOWING CONDITIONS MUST BE FULFILLED,

1) THE INCOMING GENERATOR VOLTAGE IS ALMOST EQUAL TO THE BUS VOLTAGE.

2) THE GENERATOR FREQUENCY IS EQUAL TO OR SLIGHTLY HIGHER THAN THE BUS FREQUENCY.

3) WITH THE CONDITIONS 1) AND 2) MET, THE GENERATOR CIRCUIT BREAKER MUST BE CLOSED AT THE EXACT INSTANT WHEN THE GENERATOR VOLTAGE IS IN PHASE OPPOSITION TO THE BUS VOLTAGE(SYNCHRONISM).

THE FOLLOWING DESCRIBES. AS AN EXAMPLE, HOW TO PUT NO.2 ONTO THE MSB BUS ALREADY SERVED BY NO.l.

B. ENGINE START AND VOLTAGE ESTABLISHMENT

START NO.2 ENGINE AND LET NO.2 VOLTAGE ESTABLISH IN ACCORDANCE WITH STEPS A AND B, PARAGRAPH 3-2.

C. VOLTAGE CHECK AND ADJUSTMENT

COMPARE NO.2 VOLTAGE WITH BUS USING THEIR RESPECTIVE VOLTMETER LOCATED ON SYNCHRO PANEL. IF NOT EQUAL, ADJUST NO.2 VOLTAGE TO NO.l VOLTAGE (ASSUMED TO BE 450V AC).

D. FREQUENCY CHECK AND SYNCHRONIZING

COMPARE NO.2 FREQUENCY WITH BUS USING THEIR RESPECTIVE FREQUENCY METER LOCATED ON SYNCHRO PANEL ON CON¬FORMATION THAT THE FREQUENCY DIFFERENCE IS SMALLflHZ OR LESS), SET THE SWITCH "SYNCHROSCOPE" TO NO.2 AND OBSERVE THE MOVEMENT OF THE SYNCHROSCOPE POINTER AS WELL AS THE BRILLIANCE CHANGE OF THE SYNCHRO LAMPS;

1) SYNCHROSCOPE POINTER IS ROTATING IN "FAST" DIRECTION (CLOCKWISE) THE GENERATOR FREGUENCY(i.e„ NO,2'S) IS HIGHER THAN THE BUS FREQUENCY (i.e., NO.l'S). THE SEQUENCE OF THE SYNCHRO LAMP BRILLIANCE CHANGE IS ALSO IN A CLOCKWISE DIRECTION.

2) SYNCHROSCOPE POINTER IS ROTATING IN "SLOW"DIRECTION(ANTI- CLOCKWISE) THE GENERATOR FREQUENCY IS LOWER THAN THE BUS FREQUENCY,

THE SEQUENCE OF THE SYNCHRO LAMP BRILLIANCE CHANGE IS ALSO IN ANTICLOCKWISE DIRECTION.

3) SYNCHROSCOPE POINTER IS STOPPING

THE GENERATOR AND BUS FREQUENCIES ARE THE SAME.

THE POSITION OF THE SYNCHROSCOPE POINTER(ASSUMED TO BE

STATIONARY) INDICATED THE RELATIVE PHASE ANGLE.

4) SYNCHROSCOPE POINTER IS AT 12 O'CLOCK POSITION WHETHER THE SYNCHROSCOPE POINTER IS MOVING SLOWLY OR STATIONARY, THIS CONDITION INDICATES THAT THE GENERATOR AND BUS VOLTAGES ARE IN PHASE(SYNCHRONISM).

AT THAT MOMENT, THE TWO OUTSIDE SYNCHRO LAMPS WILL BE ON AT THE SAME BRIGHTNESS WHILE THE MIDDLE TOP ONE WILL BE COMPLETELY DARK.

E. CLOSING THE GENERATOR ACB AT SYNCHRONISM

OBSERVING THE SYNCHROSCOPE OR SYNCHRO LAMPS, OPERATE

"GOVERNOR MOTOR" SWITCH FOR NO,2 TO RAISE OR LOWER AND BRING NO.2 FREQUENCY ABOUT 0.3HZ HIGHER THAN THE BUS FREQUENCYflN THIS CASE, SYNCHRO SCOPE POINTER WILL ROTATE IN "FAST' DIRECTION AND COMPLETE ONE ROTATION IN 3 OR 4 SECONDS),

OPERATE "ACB CONTROL" SWITCH FOR D/G2 TO CLOSE A LITTLE PRIOR TO SYNCHRONISM, ANTICIPATING A TIMING THAT NO.2 ACB BE CLOSED AT THE EXACT INSTANT OF SYNCHRONISM.

F. LOAD DIVISION

ON CLOSURE OF NO.2 ACB, OPERATE "GOVERNOR MOTOR" SWITCH FOR NO,2 TO RAISE SO THAT NO,2 TAKES ON KW LOAD AND LET EACH GENERATOR SHARE THE LOAD IN PROPORTION TO THEIR CAPACITY RATIO,

ALSO OPERATE "GOVERNOR MOTOR" SWITCH FOR NO.l IF NECESSARY TO MAINTAIN THE BUS FREQUENCY AT 60HZ. THEN POSITION "SYNCHROSCOPE" SWITCH TO OFF,

G. LOAD SHIFT

TO REMOVE ONE OF THE GENERATORS RUNNING IN PARALLEL, FIRST TRANSFER THE LOAD ON THAT GENERATOR TO THE OTHER GENERATORS,

WHEN THE KW OUTPUT OF THIS GENERATOR IS REDUCED TO ALMOST ZERO, REMOVE THE GENERATOR FROM THE BUS BY OPENING ITS ACB.

FOR EXAMPLE, TO REMOVE NO.l RUNNING IN PARALLEL WITH NO.2 AS MENTIONED ABOVE, OPERATE 'GOVERNOR MOTOR" SWITCH FOR NO.l TO LOWER;

LOAD ON NO.l TRANSFERS TO NO,2 ALSO OPERATE "GOVERNOR MOTOR" SWITCH FOR NO.2 IF NECESSARY TO MAINTAIN THE BUS FREQUENCY AT 60HZ.

WHEN NO.l OUTPUT IS REDUCED TO ABOUT 5% OF ITS RATED OUTPUT OPERATE "ACB CONTROL" SWITCH FOR NO.l TO OPEN TO REMOVE NO, 1 FROM THE BUS,

CAUTIONS

1) PAY ATTENTION TO THE VARIATION IN BUS FERQUENCY DURING THE LOAD DIVISION OR SHIFT CONTROL, AND BE SURE TO MAINTAIN IT AT 60HZ.

2) PAY ATTENTION TO THE LOADING CONDITION OF THE GENERATORS REMAINING ON THE BUS DURING THE LOAD SHIFT CONTROL, AND DO NOT OVERLOAD IT OR THEM.

3) IF THE OUTPUT OF A GENERATOR IS REDUCED BELOW O KW DURING THE LOAD SHIFT CONTROL, REVERSE POWER RELAY(RP SETTING : 10% OF RATED OUTPUT, TIME SETTING : 10 SEC) WILL OPERATE AND TRIP THE GENERATOR ACB.

3-4. STOPPING A GENERATOR

A. MANUAL PROCEDURE

OBSERVE THE FOLLOWING SEQUENCE OF STEPS:

1) REMOVE LOAD FROM THE GENERATOR(SINGLE OPERATION) OR TRANSFER LOAD ON IT TO THE OTHER GENERATOR (PARALLEL OPERATION).

2) OPEN THE GENERATOR ACB BY OPERATING ITS "ACB CONTROL" SWITCH TO OPEN,

3) STOP THE GENERATOR ENGINE BY OPERATING "ENG CONTROL" SWITCH TO STOP.

B. OVERLOAD PROTECTION (AUTOMATIC GENERATOR DISCONNECTION)

EACH GENERATOR IS PROTECTED AGAINST OVERLOADS AND SHORT-CIRCUITS BY TYPE HOR OVERCURRENT TRIP DEVICE, RESPECTIVELY,

DEVICE IS PART OF THE GENERATOR ACB AND TRIP THE ACB IN THE EVENT OF AN OVERLOAD OR SHORT-CIRCUIT.

FUNCTION OF APR DEVICE

LONG TIME DELAY

THIS DEVICE HAS THREE FUNCTIONAL SECTION ; LONG TIME DELAY-TRIPS ACB, INVERSE TIME DELAY, 110% RATED GENERATOR CURRENT PICKUP, 40 SECS. TIME DELAY AT 120% OF PICKUP CURRENT.

SHORE TIME DELAY

TRIPS ACB DEFINITE TIME DELAY, 300% OF RATED GENERATOR CURRENT PICKUP, 400 mSEC. TIME DELAY AT OVERCURRENT HIGHER THAN PICKUP CALIBRATION AT 300% PICKUP CURRENT.

PREFERENTIAL ALARM

CAUSES OPERATION OF PREFERENCE TRIPPING SYSTEM (SEE SEC. 2 CHAPTER 5), INVERSE TIME DELAY, 100% OF RATED GENERATOR CURRENT PICKUP, 10 SEC, TIME DELAY AT 120% OF LONG TIME DELAY PICKUP,