M E M S A

CLEARWATER, FLSeptember 5, 2002

Mining Electrical Maintenance and Safety Association

FULLY AUTOMATIC BACKUP GENERATOR

SYSTEM

Larry CassonDrummond Co. Inc.

METHODS OF APPLYING POWER GENERATORS

1. STAND ALONE GENERATOR(S)• One or more generators provide all the real power

(KW) and reactive power (KVAR) required by the load. Paralleling generators require KW and KVAR sharing.

2. BASE LOADING• One or more generators providing constant real

output power (KW) and reactive power (KVAR). May be expressed as power (KW) and power factor (PF).

34,500 VOLTSGENERATOR

# 1GENERATOR

# 2

OVERHEAD LINE # 1

OVERHEAD LINE # 2

4160 VOLTS

UNLOADING TRAIN WITH DUAL CAR DUMPER AND POSITIONING CARS WITH A TRAIN CAR INDEXER

POWER IN KW

MANUAL SWITCH TO GENERATORS

MANUAL SWITCH TO INCOMING POWER

BASICS

KW

KVARKVA

POWER TRIANGLE

PF = COS of included angle = KW/KVA

Included angle

KW

KVAR

POWER TRIANGLEBase loading

Throttle

Voltage regulator

+ KW- KW

+ KVAR

- KVAR

4 POWER QUADANTS

+ KVARProducing

REVERSE POWER PROTECTION REQUIRED

-KVAR Absorbing

UNDERGROUND 14,400 VOLT SYSTEM

KW

KVAR

ONE GENERATOR RUNNING

WHY USE GENERATORS

• BACKUP POWER SYSTEM• REDUCE POWER SYSTEM LOADING• HELP STABILIZE VOLTAGE