JLG 67SL Service Manual - Manual (Page 111)

SECTION 5 - JLG CONTROL SYSTEM
3121322 – JLG Lift – 5-11
5.7 ENGINE CONTROL SYSTEM
Functional Description
NOTE: For desciptions in ( ), refer to Figure 6-23., Electrical
Schematic - Sheet 6 of 15
1. An ignition input on X1/1 (15) creates an output at
X2/8 (fuel solenoid). (On H005559, this input also
powers up the glow plug relays at X2/23). Initially all
6 LEDs will flash 3 times, to test the system and the
LEDs. After this startup check, only the OK LED
should flash. An additional 7 seconds later, the sys-
tem monitoring system is activated and the circuit
recognizes fault input signals.
2. A start input on X1/2 (50e) creates an output at X2/7
(start relay). This input is ignored by the system after
10 sec. to protect against short circuit, or switch
"contact stuck closed" situations. The output is also
dependant on the alternator input signal.
3. The alternator input X2/10 (W) is monitored in the
following way:
a. When a start signal is applied to X1/2 (50e), the
input on X2/10 needs to be less than 4Hz to
enable an output at X2/7 (50f). (Start lockout fea-
ture when engine is running).
b. When X2/10 reaches 150Hz, the X2/7 output is
cut (engine is sensed to be running and start
signal is cut).
NOTE: An input frequency of 80Hz can be achieved when
the engine is cranking, but not started. If this occurs,
increase the sensing trip point in the E-prom on the
circuit board to 150Hz. This ensures the engine is
running before cutting the start signal.
c. When a start signal is applied to X1/2 (50e) and
the input on X2/10 remains zero, after 1 second
of cranking, the output X2/7 is cut and the G LED
turns on (no input from alternator).
NOTE: The field current strength, during initial start in cold
temperatures, from the W input (600mA) can be
insufficient to generate a sensed signal. If this
occurs, increase the field current sensed to 1A by
reducing the exciter resistor to 23.5 Ohm from 39
Ohm. This ensures sufficient initial start signal
strength in cold weather.
d. If X2/10 goes to zero when the engine is run-
ning, the output to X2/8 is cut and the G LED
turns on (lost input from alternator).
4. There is a 6 second time delay between start
attempts. The 6 seconds starts when there is zero
input on X2/10.
5. The main use of the additional push button "Start
Assist" is to prime the fuel line. When this button is
operated simultaneously with the start button, the
start cut out control feature is ignored. This condi-
tion continues for 3 minutes during which only one
start attempt can be made.
6. When there is an imput to X2/11 the Glow Time LED
(lamp on H005559) is turned on. The duration of the
time on is controlled by the glow relays.
7. When there is an air intake filter clogged input
(ground) on X2/4 (Air), the fault LED on the panel is
illuminated. This is an indication warning only. It
does not cut the engine. This warning signal
Vertragshandler
ehb electronics
Start
Vertragshandler
ehb electronics
Start
Glow
Air
Oil
Alt.
OK
Temp.
OR
H005559 1001094781