Section 2 Engine Dc Control System; Printed Circuit Board; General Theory; Circuit Board Connections - Generac Power Systems GP Series Diagnostic And Repair Manual

Engine DC Control System
Section 2

Printed Circuit Board

General Theory

The printed circuit board is responsible for cranking,
startup, running and
interconnects with other components of the DC control
system to cycle them on and off at the proper times. It is
powered by fused 12 VDC power from the unit battery.

Circuit Board Connections

See Figure 2-1. The circuit board mounts 12-pin
receptacle J2 and 5-pin receptacle J1.
12-pin receptacle J2, the associated wires and the
function of each pin and wire.

Dip Switch Positions

NOTE: See Figure 2-1. These switches must remain in
the factory settings.
Stepper Motor Rotation
1.
a. Switch set to ON for clockwise rotation
(Factory Position).
b. Switch set to OFF for counterclockwise
rotation.
Frequency Setting
2.
a. Switch set to OFF for 60 Hertz (Factory
Position).
b. Switch set to ON for 50 Hertz.
A
C
A. Dip Switches
B. Sensing LED
Figure 2-1. Printed Circuit Board
Diagnostic Repair Manual
shutdown operations.
Table 2-1 shows
B
C. J2 Connector
D. J1 Connector
004571
Table 2-1. Receptacle J2 Functions
Terminal Wire
It
1 15B
2 83
3 TR1
4 0
5 167
6 TR2
7 86
8 229
9
10 44S
22S
11
12 11S
NOTE: J1 connector is utilized for governor control.

Battery

Recommended Battery

When anticipated
consistently above 32 °F. (0 °C.), use a 12 VDC Group
U1 storage battery capable of delivering at least 360
CCA (cold cranking amperes).
D
Function
12 VDC input when the start stop relay
(SSR) is energized.
Ground input when the idle control switch
(SW2) is placed in the CLOSED position
AC voltage input from the idle control
transformers.
Common ground for the PCB
12 VDC input when SW1 is placed in
the START position. Ground input
when SW1 is placed in the STOP
position.
AC voltage input from the idle control
transformers.
Fault shutdown circuit. When grounded
by closure of the low oil pressure
switch (LOP) engine will shut down.
Switched to ground for start stop relay
(SSR) operation.
NOT USED
AC input for frequency control. 11S/
44S 240VAC (Older Style)
AC input for frequency control. 11S/
22S 240 VAC (Newer Style)
NOT USED
AC input for frequency control. 11S/
44S 240 VAC or 11S/22S 240 VAC
ambient temperatures will be
7