Low Coolant Level Switch; Overspeed Shutdown; Pcb Operation Led's; Overcrank Shutdown - Generac Power Systems 004912-0, 004912-1, 004913-0, 004913-1 Owner's Manual

Figure 1.5- High Coolant Temperature Switch
1.7.3

LOW COOLANT LEVEL SWITCH

Should engine coolant level drop below the level of
the high coolant temperature switch, it is possible for
the engine to overheat without automatic shutdown.
To prevent such overheating without automatic shut
down, the engine has a low coolant level sensor. If the
engine coolant drops
automatically shuts down (Figure 1.6).
Figure 1.6 - Low Coolant Level Sensor
1.7.4

OVERSPEED SHUTDOWN

The Pre-pack circuit board on liquid cooled units
receives AC frequency (rpm) signals directly from the
stator AC power windings, via sensing leads S15 and
S16. Should AC frequency exceed about 72 Hz,
circuit board action will automatically shutdown the
engine (Figure 1.7).
Figure 1.7 - Control Module Assembly
Circuit Board
J2
E
A
M14 M15
M1 M1 M5 M M8 M1 M1 M1 M1 M1 M1 M M Q7
C1
R1
U1
M10
SW1
BR1 U12
R56 CR1
R12
C4
Q1
U6
R11 R10 CR7
CR37
K4
Q4
K2
Q5
Q3
K3
K1
M9
Q13
M2
R55
CR41
2002 GENERAC POWER SYSTEMS, ASSY #076009A
6 Generac ® Power Systems, Inc.
Section 1 — General Information
Centurion Liquid-cooled 15 kW and 25 kW Generators
too low, the
PRE-PACKAGED STANDBY
U13
U14
U15 U17
C17
C18
C12
R68 R60
C21
C25 C22
U16
C3 C24
Q9
C2
C5 U2
C
U18
U3
U7
U9
Q12 U10
C23
Q2
C20
C8
Q11
C15
Q15
C10
C9 C 1 C11
LED2
U20
C7
C14 C16
Q6
C13
CUT R83
FOR 50HZ
1.7.5
• LED 1 is RED. The LED will be on when utility
sensing is NOT available to the circuit board. This
LED will function only when the AUTO/OFF/
MANUAL switch is set in the Auto position.
• LED 2 is YELLOW. This LED will be on when the
circuit board battery charger is on. This LED will
cycle on and off with the battery charger, 4.85
hours on the 4.85 hours off.
• LED 3 is GREEN. This LED will flash when the
circuit board has load voltage available to it. This
LED will function when voltage is available across
T1 and T2.
1.7.6
After 90 seconds of crank-rest cycles, this function
ends cranking if the engine fails to start in that 90
second span.
engine
1.7.6
This clearly labeled fuse is located on the front panel
of the control system. It protects the panel wiring and
components from damaging overload. Always
remove this fuse before commencing work on the
generator. The unit will not start or crank if the fuse
is blown. Replace the fuse with one of the same size,
type, and rating. Generac normally uses an AGC fuse
rated at 15 amps (part number 022676).
1.8

1.8.1 UNPACKING PRECAUTIONS

Handle shipping cartons and crates with care. Use
care to avoid damage from dropping, bumping,
collision, etc. Store and unpack cartons with the
proper side up, as noted on the shipping carton.

1.8.2 INSPECTION

After unpacking, carefully inspect the generator for
any damage that may have occurred during
shipment. If loss or damage is noted at the time of
delivery, have the person(s) making delivery note all
damage on the freight bill or affix their signature
under the consignor's memo of loss or damage.
M3
Q14
1.9
U5 U4 LED3
U19
When lifting or hoisting equipment is used,
!
be careful not to touch overhead power lines.
C19
U8
The generators weight of more than 900
pounds requires proper tools, equipment, and
Q16
qualified personnel to be used in all phases of
LED1
handling and unpacking.
M4

PCB OPERATION LED'S

OVERCRANK SHUTDOWN

DC FUSE

UNPACKING

LIFTING THE GENERATOR