Guardian 4389 Repair Manual page 81

DC CONTROL
• Should utility voltage drop below approximately 60 percent of the nominal source voltage, a 15-second timer on
the circuit board will turn on.
• In Figure 2, the 15-second timer is still timing and engine cranking has not yet begun.
• The AUTO-OFF-MANUAL switch is shown in its AUTO position. Battery voltage is available to the circuit board,
via Wire 13, 15 amp fuse (F1), Wire 15, the AUTO-OFF-MANUAL switch (SW1), Wire 15A, and Pin 10 of the
circuit board connector.
11
22
TX
225A N2
56VA
224A
225
1VA
224 N1
+
-
0 0 12VDC ACCESSORY SOCKET
15B
13
13
0 0
F2
15B
0
15A
17
23
194
13
0
239
14
0
15
SCR
17 15
56
18
0
0 0
17
15
0 0
18
C1-5
PART 4
C2-6
C2-5
N2
N1
17
F1
15
15
15 15A
15 15
15
23
194
239
14
15
13
C2-1
16 16
14
C1-1
SC FS
0 0
0
G
IM1
D
SP1
18
IM2
D
SP2
194 23 11 22
22
SW1
239
N
11
RED
SC
BATTERY
SM
12V
BLACK
CUSTOMER
SUPPLIED
G G
Figure 2. Circuit Condition - Initial Dropout of
SECTION 4.2
OPERATIONAL ANALYSIS
N1 240VAC
UTILITY
N2
INPUT
12Vdc
23
TRANSFER
RELAY
194
COIL
22
N
33
120V
POWER
120V
WINDING
(STATOR)
44
CB1
11
11
N N
240V
CB3
L
N L
G G
EXTERNAL
GFCI
OUTLET
Utility Source Voltage
23
TR
194
CUSTOMER
CONNECTIONS
Page 79