JLG 800S Service Manual - Manual (Page 246)

SECTION 4 - BOOM & PLATFORM
4-30 – JLG Lift – 3121139
VALVE DRIVER ERRORS
There are three possible level valve driver errors, short to
battery, short to ground, and open circuit.
1. In the case of a short to ground or an open circuit,
the platform valve cannot be turned on and the fol-
lowing will occur:
a. All interactions with platform leveling shall cease
b. The Electronic Leveling System Fault Lamp shall
flash (to indicate that the leveling function has
been lost).
c. The platform alarm will sound.
d. A system fault will be logged.
e. All function speeds (lift, swing, telescope and
drive) will be placed in creep mode (except
when the platform is in the transport position).
2. In the case of a short to battery on one of the plat-
form leveling valves, the valve cannot be turned off
and the following will occur:
a. The platform dump valve will be turned off to
prevent unintended tilting of the platform.
b. All interactions with platform leveling shall
cease.
c. The Electronic Leveling System Fault Lamp shall
flash (to indicate that the leveling function has
been lost).
d. The platform alarm will sound.
e. A system fault will be logged.
f. All function speeds (lift, swing, telescope and
drive) will be placed in creep mode (except
when the platform is in the transport position)
3. In the case of a short to battery on the platform
dump valve, the valve cannot be turned off. The
controllability of the platform leveling function will be
impaired and the following will occur:
a. All interactions with platform leveling shall
cease.
b. The Electronic Leveling System Fault Lamp shall
flash (to indicate that the leveling function has
been lost).
c. The platform alarm will sound.
d. A system fault will be logged.
e. All function speeds (lift, swing, telescope and
drive) will be placed in creep mode (except
when the platform is in the transport position).
Lift, swing, drive and telescope will continue to operate
In each of the cases above it shall be necessary to re-
cycle the EMS to clear the fault. Operable functions shall
be in the creep mode except while below elevation.
TILT SENSOR ERRORS
If the secondary tilt sensor is faulty, the control system will
continue to utilize information from the primary sensor.
If the primary sensor is faulty, the control system will
switch to the backup sensor for control.
In both cases above the following will occur:
1. The Electronic Leveling System Fault Lamp will flash
(to indicate that there is a leveling fault).
2. The platform alarm will sound.
3. A system fault will be logged.
4. All function speeds (lift, swing, telescope, jib and
drive) will be placed in creep mode (except when
the platform is in the transport position).
5. Automatic platform angle control remains active.
Lift, swing, drive and telescope will continue to operate.
In each of the cases above it will be necessary to re-cycle
the EMS to clear the fault. Operable functions shall be in
the creep mode except while below elevation.