Generac Power Systems MC - Manual (Page 47)

2.4.1-GENERAL
SECTION 2.4
MODEL 6897-4
2.4.1.1-INTRODUCTION
The Model 6897-4 (MC-40) alternator incorporates several new components
in its DC control system. The new components replace the printed circu­
it board used on earlier models. They will improve starting and simpli­
fy component testing, removal and replacement. New components are:-
1. )- Choke Pulse Module (CM)
2. )- Control Relay (CR)
3. )- Field Boost Module (FB)
2.4.1.2-CHOKE PULSE MODULE
The Choke Pulse Module performs
several important functions, rel­
ated to engine starting. These
functions are:-
1. )-Provides the necessary compo­
nents for delivery of a pulsing
voltage to the automatic choke
solenoid during cranking.
2. )-Provides the required circui­
try for energizing the fuel lock-
off solenoid and (electric) fuel
pump during cranking, before the
control relay (CR) is energized.
2.4.1.3-CONTROL RELAY (CR)
The Control Relay (CR) is equipped
with a pushbutton for manually cl­
osing the CR contact. The pushbut­
ton can be identified by the words
FUEL PUMP on the unit control pan­
el. To prime the carburetor prior
to cranking the engine, depress
the pushbutton. This action will
energize the Fuel Lockoff Solenoid
open and operate the (electric)
Fuel Pump. After a start, the CR
remains energized to hold the Fuel
Lockoff Solenoid open and operate
the Fuel Pump. (While cranking,
part of the Choke Pulse Module cir­
cuit performs the latter function.)
O
MAIN
BREAKER
O
® -©
STOP STAUT
Q 4000 O
I
MC-40
WATT "------------ '
Control Relay (CR)
2.4-1