Initial Dropout Of Utility Source Voltage - Guardian 4389 Repair Manual

SECTION 4.2
OPERATIONAL ANALYSIS
Refer to Figure 2, above. Should a "Utility" power source failure occur, circuit condition may be briefly described
as follows:
• The circuit board constantly senses for an acceptable "Utility" source voltage, via transfer switch fuses F1/F2,
transfer switch UTILITY 1 and UTILITY 2 terminals, connected wiring, control panel UTILITY 1 and UTILITY 2
terminals, the sensing transformer (TX), and Wires 224/225.
11
22
11
22
ELECTRONIC 4 C2-10
VOLTAGE 4
REGULATOR 0
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 78

INITIAL DROPOUT OF UTILITY SOURCE VOLTAGE

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 6 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
= 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
14
66A
9
239
15A
17
11
12 15
13 0
14 225
15 224
16
17
11
22
225A
224A
225
224
0 0
13
0 0
13
15A
23
194
225
14
224
239
66A
15A