Guardian 5240 - Engine Startup and Running

= 12 VDC ALWAYS PRESENT
=AC VOLTAGE
= GROUND FOR CONTROL PURPOSES
= 12 VDC DURING CRANKING ONLY
= 12 VDC DURING ENGINE RUN CONDITION
225B
224B
13
15
56
16
86
15A
224
15B
PRINTED CIRCUIT
11
13
14
12
CONTROL
BOARD
5
8
9
10
6
7
J1
2
3
4
1
VOLTAGE
REGULATOR
ELECTRONIC
MANUAL
SW2
AUTO
23915
SW1
194
194 15A
15A
194
6
2
4
0
4
11
22
56
0
0
13
0
CHARGER
2
1
0
BATTERY
3
1
2
13
18
85
239
56
4
23
14
14
56
15A
239
15
194
4
F1
15
0
22 11
16 0
225
86 LC2
14
0
225B
23
225B
224B
194
0
86
2
14
16
13
4
6
0
0
224B
85
18
86
13
GOVERNOR
ACTUATOR
J2
18
1823
224
0
0
11
22
15
15
15
16
17
18
19
20
21
22
23
LC1
LC2
85
85LC1
LC2
LC1
14
225
15B
0
90 CS
14
14
SCR
Page 88
PART 4
DC CONTROL
SECTION 4.2
OPERATIONAL ANALYSIS
ENGINE STARTUP AND RUNNING
With the fuel solenoids open and ignition occurring, the engine starts. Engine startup and running may be briefly
described as follows:
• Voltage pulses from the ignition magnetos are delivered to the circuit board via Wire 18. Once the circuit board
determines that the engine is running, the circuit board (a) terminates cranking, and (b) terminates the choke
solenoid (CS), and (c) turns on an “engine warm-up timer”.