JLG 80SL, Service Maintenance Manual

Page: 114 / 162

SECTION 5 - JLG CONTROL SYSTEM
5-8 – JLG Lift– 3121325
5.4 PNP5 CIRCUIT BOARD
System
The PNP5 circuit board is an electronic printed circuit
board mounted on the Din rail situated in the MTB (refer
to Figure 5-1., Main Terminal Box).
Operation
The circuit acts on the control system in the following
ways:
1. Amplifies signals to activate the drive and series/par-
allel hydraulic valves.
2. Activates the oscillating axle hydraulic valves when
the platform is not elevated and the drive function is
operated.
3. Enables the output to activate 2nd pump (if fitted
and selected) when the platform is not elevated.
Also delays this output until the engine speed and
torque are sufficient. This delay is adjustable by
means of a potentiometer on the board.
Adjustment
• With the platform stowed, position the drive speed
select switch to ’High Speed.’ Operate the drive func-
tion and adjust the potentiometer to produce a 2 sec-
ond time delay pump 2 output (signal on J2/2)
following the engine speed increase.
5.5 TRIGGER CONTROL CIRCUIT CARD
Relay K1
NOTE: Refer to Table 5-9 for numbers.
1. Energized when there is a trigger input at 2.
2. When a start input signal is applied to 5, and there is
no input from the trigger switch (no input on 2), the
start ouput signal passes through the N.C. contacts
on relays K1 and K2 to 6.
3. When a trigger input signal is present at 2, there is a
6 second window to receive a pump/lower input sig-
nal at 4 to keep K1 energized. This trigger input
passes through the N.O. contacts to produce a trig-
ger output on 3.
4. If there is no pump/lower input within this time (e.g.
the trigger switch is taped closed), K1 is de-ener-
gized and the trigger output at 3 is cut.
Relay K2
1. Energized when there is a trigger input at 2.
2. This input passes through the N.O. contacts to pro-
duce a drive output on 8.
3. When this trigger input is removed, there is a 3 sec-
ond time delay before K2 is de-energized and the
drive output on 8 is cut. (Anti bounce function for the
drive function).
Table 5-6. PNP Circuit Board - I/O
OU
T
Ser
is P
arallel
Dr
iv
e
Osc. Ax
le
Pu
m
p 2
IN
J1/3 J1/5 J2/3 J2/5
Drive
J1/1
1 1
Series Parallel
J1/4
1
Pump 2
J2/2
1*
S2.5m Limit Switch
J2/4
1
High Engine (RPM)
J2/6
1*
Board Power
24V (Vs) J1/2
Ground J2/1
*Adjust Potentiometer to delay Pump 2 output after RPM
input. (allows engine to begin torque before adding load)
Table 5-7. Connector J1
Drive In J1/1
Power 24V J1/2
Series Parallel Out
J1/3
Series Parallel In J1/4
Drive Out
J1/5
Table 5-8. Connector J2
Ground J2/1
Pump 2 In J2/2
Oscillating Axle
J2/3
S 2.5 In J2/4
Pump 2 Out
J2/5
Engine RPM In J2/6