16 Generac
®
Power Systems, Inc.
3.7
PROTECTION SYSTEMS
3.7.1
LOW OIL PRESSURE SWITCH
This switch (Figure 3.3) has normally closed contacts
that are held open by engine oil pressure during
cranking and operating. Should oil pressure drop
below the 8 psi range, switch contacts close, and the
engine shuts down. The unit should not be restarted
until oil is added. The AUTO/OFF/MANUAL switch
must then be turned to OFF and then back to AUTO.
3.7.2
HIGH TEMPERATURE SWITCH
This switch’s (Figure 3.3) contacts close if the tem-
perature should exceed approximately 140º C (284º
F), initiating an engine shutdown. The generator will
automatically restart and the LED on the generator
control panel will reset once the temperature has
returned to a safe operating level.
Figure 3.3 – Low Oil Pressure and
High Temperature Switches
3.7.3
OVERCRANK
This feature prevents the generator from damaging
itself when it continually attempts to start and anoth-
er problem, such as no fuel supply, prevents it from
starting. The unit will crank and rest for a preset time
limit. Then, it will stop cranking, and the LED on the
generator control panel will light indicating an over-
crank failure. The AUTO/OFF/MANUAL switch will
need to be set to OFF and then back to AUTO to reset
the generator control board.
NOTE:
If the fault is not repaired, the overcrank feature
will continue to activate.
3.7.3.1 Approximate Crank Cycle Times
• 15 seconds ON
• 7 seconds OFF
• 7 seconds ON
• 7 seconds OFF
• Repeat for 45 seconds
Approximately 90 seconds total
3.7.4
OVERSPEED
This feature protects the generator from damage by
shutting it down if it happens to run faster than the
preset limit. This protection also prevents the gener-
ator from supplying an output that could potentially
damage appliances connected to the generator cir-
cuit. Contact the nearest Generac Authorized Dealer
if this failure occurs.
4.1
FUSE
The generator panel’s 15 amp fuse (Figure 4.1) pro-
tects the DC control circuit against overload. The fuse
is wired in series with the battery output lead to the
panel. If the fuse element has melted open, the engine
will not crank or start. Replace the fuse using only an
identical 15-amp replacement.
The generator panel’s 5 amp fuse protects the battery
charge circuit against overload. If the fuse element
has melted open, battery charging capabilities will
not be possible. Replace the fuse using only an iden-
tical 5 amp replacement. To remove fuse, push cap
down and rotate counterclockwise.
Figure 4.1 – Generator Control Panel
4.2
CHECKING THE ENGINE
OIL LEVEL
For oil capacities, see “Specifications,” Section 1.5.
For engine oil recommendations, see Section 4.3.1.
To check the engine oil level, proceed as follows
(Figure 4.2):
1. Start the generator by moving the Auto/
Off/Manual switch to the MANUAL position. Allow
it to run for a short while and then shut it down
by moving the switch to the OFF position.
HIGH TE
M
P.
OVE
R
S
PEED
LO
W
OIL
S
Y
S
TE
M
S
ET
OVE
R
C
RAN
K
MAN
.
S
ET
OFF
A
UTO
15
A
FU
S
E
EXE
R
CI
S
E
TI
M
E
R
PO
W
E
R
S
Y
S
TE
MS
, I
N
C.
L o c a t e y o u r
n e a r e s t
d e a le r
a t :
R
FU
S
E
5
A
E X E
R
C I
S
E
R
N
O T
S
E T
N
O
U T IL IT Y
S
E
N S
E
4
F L
A S
H I
N
G
R
E D
L E D
S
=
F L
A S
H I
N
G G
R
E E
N
L E D =
Oil Filter
Oil
Drain
Hose
Low Oil Switch
High Temp Switch
Loose
n
Section 4 — Maintenance
Air-cooled 8.5 kW Generator
