Home Standby Generator Fault Codes
What do the Fault Codes mean on my home standby generator system?
PLEASE NOTE: The normal output of the generator's digital display will show the total hours of run time for the unit. Unless the letters "FC" are present, there is no fault condition and the default hour meter is being displayed.
Servicing the System
Before performing any generator maintenance, always perform the following steps:
Set generator's circuit breaker to its OFF position.
Set control panel system switch to OFF.
Utility voltage is present at generator control panel. Disconnect power before servicing control panel by removing the fuses from the transfer switch.
After all servicing has been completed, replace fuses in transfer switch, replace 15 Amp fuse in control panel, set system switch and circuit breaker ON and reset exercise timer. (See Setting Exercise Timer).
Fault Detection System
The generator may have to run for long periods of time with no
operator present. For that reason, the system is equipped with
sensors that automatically shut down the generator in the even of
potentially damaging conditions, such as low pressure, high
temperature, over speed, and other conditions.
The generator's control panel has a digital display that shows
fault codes, like "FC_1". The table below lists the detected
fault, the fault code as displayed on the control panel, and the
number of LED flashes (also described as 'blinks') seen on the
remote LED indicator.
Reset Fault Detection System
The operator must reset the fault detection system each time
it activates. To do so, place the control panel system switch in
the OFF position for 30
seconds or more. Remedy the fault condition, then return the
generator to service by installing the 15 Amp fuse, placing the
system switch in the AUTO
position, and resetting the exercise timer. See Setting Exercise
Timer in Operation.
A description of each fault and suggested remedies are as
No LED - Discharged Battery
If there is a detected fault condition but the LED is not
blinking, this is because the battery is completely discharged.
To remedy the problem, remove the 15 Amp fuse and disconnect the
battery store for analysis. Reinstall battery after it has been
fully recharged, connecting the NEGATIVE cable last. Then reset the
fault detection system, as described earlier.
The remote LED indicator is installed at a convenient inside
location. The LED will remain lit when the generator is in
AUTO. Should a system
fault be detected, the LED will turn on and off in a series of
blinks that identify the problem. The blink pattern is repeated
with a brief pause between each series of blinks.
Low Battery Voltage (FC_1)
This fault is indicated by fault code FC_1 and one blink on
the LED indicator. This condition occurs if the generator cannot
start because the starting battery output power is below that
needed to crank the engine. Causes for this problem may be a
faulty battery or battery charge circuit.
To remedy this problem, contact your local service center to
check the battery charge output. Remove the 15 Amp fuse and
disconnect the battery from the generator. Take the battery to a
local battery store for analysis.
Reinstall the battery (replace if necessary - see Battery in
Final Installation Considerations in the installation manual).
Then reset the fault detection system, as described earlier.
Low Oil Pressure (FC_2)
This fault is indicated by fault code FC_2 and two blinks on
the remote LED indicator. The unit is equipped with an oil
pressure switch that uses normally closed contacts held open by
engine oil pressure during operation. Should oil pressure drop
below the 8 psi range, switch contacts close and the engine is
To remedy the low oil pressure condition, add the recommended
oil to the FULL mark on the dipstick.
If the low oil pressure condition still exists, the engine
will start, then shut down again. The fault code will appear and
the LED will flash. In this case, contact an authorized service dealer.
Low Voltage (Generator, FC_3)
This fault is indicated by fault code FC_3 and three blinks on
the LED indicator. This condition is caused by a restriction in
the fuel flow, a broken or disconnected signal lead, a failed
alternator winding, the control panel circuit breaker is open, or
the generator is overloaded.
To remedy the problem, contact your installer or an authorized service dealer.
Engine Fail To Start (FC_4)
This fault is indicated by fault code FC_4 and four blinks on
the LED indicator. This feature prevents the generator from
damaging itself if it continually attempts to start in spite of
another problem, such as no fuel supply. Each time the system is
directed to start, the unit will crank for 10 seconds, pause for
10 seconds, and repeat. If the system does not begin producing
electricity after approximately 2 minutes, the unit will stop
cranking and the LED will blink.
Check to make sure the generator's circuit breaker is in the
ON position in order for the sensing leads to verify that the
unit is running.
The most likely cause of this problem is no fuel supply. Check
the internal and external fuel shut off valves to ensure they are
fully open. Other causes could be failed spark plug(s), failed
engine ignition, or the engine air filter is clogged. You may
need to contact your installer for assistance if you can't remedy
Low Frequency (FC_5)
This fault is indicated by fault code FC_5 and five blinks on
the LED indicator. This feature protects devices connected to the
transfer switch by shutting the generator down if the engine runs
slower than 55 Hz for three seconds.
This condition is caused by a failed engine component or by
excessive loads on the generator. To remedy the problem, contact
your installer or an authorized service dealer.
Engine Overspeed (FC_6)
This fault is indicated by fault code FC_6 and six blinks on
the LED indicator. This feature protects devices connected to the
transfer switch by shutting the generator down if the engine
happens to run faster than the preset limit. The overspeed fault
is detected as follows:
If the generator output frequency is 65-70 Hz, after three
seconds, the generator will shut down.
If the generator output frequency is greater than 70 Hz, the
generator will shut down immediately.
This condition is caused by a failed engine component. To
remedy the problem, contact your installer or an authorized service dealer.
High Temperature (FC_7)
This fault is indicated by fault code FC_7 and seven blinks on
the LED indicator. The contacts of the temperature switch are
normally open. If the engine temperature exceeds approximately
115°C (240°F), the fault is detected and the engine shuts
Common causes for this condition include running the unit with
all access doors removed, obstructed air inlet or exhaust port,
low oil or coolant level, or debris in the engine compartment or
To resolve the problem, let the engine cool down and remove
any accumulated debris and obstructions. Ensure that all access
doors are installed whenever the unit is running.
Transfer Switch Fault (FC_8)
This fault is indicated by fault code FC_8 and eight blinks on
the LED indicator (if transfer switch is equipped with fault
The most likely cause of this fault is a blown fuse in the
transfer switch. To remedy the problem, contact your installer or
an authorized service dealer.
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