Guardian 4389 Repair Manual page 88

SECTION 4.2
OPERATIONAL ANALYSIS
UTILITY VOLTAGE RESTORED / RE-TRANSFER TO UTILITY
The "Load" is powered by the standby power supply. The circuit board continues to seek an acceptable utility
source voltage. On restoration of utility source voltage, the following events will occur:
• On restoration of utility source voltage above 80 percent of the nominal rated voltage, a "retransfer time delay"
on the circuit board starts timing. The timer will run for about fifteen (15) seconds.
• At the end of fifteen (15) seconds, the "retransfer time delay" will stop timing and circuit board action will open
the Wire 23 circuit to ground. The transfer relay (TR) will then de-energize.
• When the transfer relay (TR) de-energizes, its normally-closed contacts close. Utility source voltage is then
delivered to the utility closing coil (C1), via Wires N1A/N2A, the closed TR contacts, Wire 126, limit switch XA1,
and a bridge rectifier.
11
22
11
22
4
ELECTRONIC C2-10
4
VOLTAGE
0
REGULATOR
6
162
CB2
C2-8
DIAGRAM KEY
BA - BRUSH ASSEMBLY
BCR - BATTERY CHARGE RELAY
CB1 - CIRCUIT BREAKER, MAIN OUTPUT
CB2 - CIRCUIT BREAKER, ALT. EXCITATION
CB3 - CIRCUIT BREAKER, EXTERNAL OUTLET, PUSH/PULL
D - DIODE
FS - FUEL SOLENOID
F1 - FUSE 15 AMP
F2 - FUSE 7.5 AMP
HTO - HIGH OIL TEMPERATURE SWITCH
IM1 - IGNITION MODULE, CYLINDER #1
IM2 - IGNITION MODULE, CYLINDER #2
LOP - LOW OIL PRESSURE SWITCH
SC - STARTER CONTACTOR
SCR - STARTER CONTACTOR RELAY
SP1, SP2 - SPARK PLUGS
SW1 - AUTO / OFF / MANUAL SWITCH
SW2 - SET EXERCISE SWITCH
SM - STARTER MOTOR
TX - TRANSFORMER, 16 Vac 56 VA & 16 Vac 1 VA (DUAL SEC.)
= 12 VDC ALWAYS PRESENT
= AC VOLTAGE
= GROUND FOR CONTROL PURPOSES
Page 86
11
3
2
1
BATTERY
CHARGER
13
2
1
0
13
C2-1
77
BATTERY CHARGE
WINDING
0
C2-4
C2-11 0
BA
0
FIELD
0
C2-9
0
C1-6
6
0
C2-7
2
DPE WINDING
(STATOR)
22
225A
224A
225B
224B
7 7 9 9
1 3 4
77
66
66
C2-2
0
0
HTO
0
55
ENGINE RUN
WINDING C1-4
(STATOR)
C2-3
4
66A
85
351
1 2 3
J2
CONTROL
PRINTED CIRCUIT
BOARD
= DC FIELD CONTROL VOLTAGE
= 12 VDC DURING CRANKING ONLY
= 12 VDC DURING ENGINE RUN CONDITION
PART 4
DC CONTROL
13
BCR
13
0
14
0
LOP
SW2
14
C1-3
86
4
66A
4 5
23
1 4
J1
194
2
86
3 23
4
194
5
56
6
18
7
66A
9
239
15A
17
11
12 15
13 0
14 225
224
15
16
17
11
22
225A
224A
225
224
0 0
13
0 0
13
15A
23
194
225
14
224
239
66A
15A