Snorkel UL25, Parts & Service Manual

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UL-25/32/40 Portable Personnel Lifts 3-3
Troubleshooting
Section
Table 3-1: Troubleshooting (cont'd)
1a) DC voltage at S28 is less than
11 VDC.
1b) Voltage is found at the ground
terminal.
1c) Between 11 VDC and 26 VDC found
at S28. Zero volts found at GND.
All voltages are referenced to Chassis ground. Using a voltmeter, place the negative probe
directly to a clean ground source on the AC motor. If equipped with battery back up,
remove back up battery before proceeding. Diconnect both chassis connector and coil
cord connector. Set voltmeter for DC voltage. Plug lift into outlet.
1) Check for voltage at the power terminals of the circuit board. Turn off key
switch and E-Stop switch. Power terminal is S28 and ground terminal is GND.
See drawing.
a) Extension harness excessive in length.
b) Low line voltage.
c) Damaged or faulty circuit board.
a) Damaged or faulty motor harness.
b) Damaged or faulty circuit board.
a) Continue to #2.
2a) No voltage is found on either
terminal.
2b) Voltage is found only on one of the
two key switch terminals.
2c) Voltage is found at both sides of the
key switch.
2) Check for voltage at the terminals of the key switch. Turn the key switch on
and and the E-Stop switch off.
a) Circuit board is damaged.
a) Ignition key switch is faulty.
a) Continue to step 3.
3a) Voltage at pin 6 does not exist or is
less than 11 volts DC.
3b) Voltage at ground pin 1 is not zero.
3c) Voltage at pin 6 is between 10 and 12
VDC, voltage at pin 1 is zero.
3) Check voltages at the chassis harness. Turn on the ignition key and turn off the E-
Stop. Disconnect the chassis harness. Check voltage of pin 6 and pin 1 of chassis
connector on the circuit board.
a) Circuit board is damaged.
a) Circuit board is damaged.
b) Ground on motor harness damaged or
connected improperly.
a) Continue to step 4.
4a) Pin 6 is not between 10 and 12 VDC.
4b) Voltage found at pin 1.
4) Plug in Chassis harness. Turn on ignition key, turn off E-Stop switch. Check
voltages at pin 1 and 6 of the chassis harness. This may require the use of a
sharp probe to pierce the insulation of the corresponding wires.
a) Damaged or shorted chassis harness.
a) Circuit board is damaged.
b) Ground on motor harness damaged or
connected improperly.
1a) Outrigger lights do not turn on.
1b) Outrigger lights tun on immediately
and no five second delay is present.
1c) Fewer than four indicator lights will
operate.
1d) All four indicator lights turn on five
seconds after ignition key is turned on.
1) Plug lift into outlet. Make sure all outriggers are extended and raised. Turn
off the E-Stop switch and turn on the ignition key. Wait five seconds for machine
to turn on and outrigger lights to light.
a) See LIFT DOES NOT TURN ON
b) Circuit board is damaged. Replace circuit
board.
a) Indicator light is damaged.
b) Chassis harness damaged or incorrectly
connected.
c) Outrigger limit switch defective or
improperly connected.
a) Continue to step 2.
2a) Motor does not run.
2b) Motor runs but will not raise.
2c) Motor attempts to start but machine
turns off and then restarts in five seconds.
2) Pull out both E-Stop switches. Activate the common and up switch on the
upper control box.
a) Continue to step 3.
a) Hydraulic system failure.
b) Damaged or improperly connected motor
harness.
c) Damaged pump solenoid.
a) Improperly connected or damaged motor
harness.
b) Improperly connected or damaged coil
cord or upper control box.
c) Damaged pump solenoid.
d) Extension harness excessive in length.
e) Low line voltage.
f) Damaged pump motor.
3a) No voltage is present at either of the
terminals on the E-Stop.
3b) Voltage is present on both terminals
of the E-Stop switch.
3c) Voltage is only present at one side of
the E-Stop switch.
3) Open the lid on the lower control box. Check for voltage at the E-Stop switch.
Ignition key is turned on E-Stop is pulled out on both the upper and lower box.
a) Circuit board is damaged. Replace circuit
board.
a) Check for correct operation of upper E-Stop
switch. Continue to step 4.
a) Replace E-Stop switch in whole or in
part.
4a) When up button is pressed, 10-12
VDC is not present at pin S26.
4b) When up button is pressed, 10-12
VDC is present at pin S26.
4) Check Circuit board lift circuit. Place voltmeter probe at lift terminal S26 at
the upper right hand side of the circuit board. See drawing(Page 3-5). Activate
the common and up switch on the upper control box.
a) Improperly connected or damaged coil
cord or upper control control box.
b) Improperly connected or damaged
chassis harness.
c) Damaged circuit board.
a) Continue to step 5.
5a) Line voltage is found between -120
and motor.
5b) Line voltage is not found between -
120 and motor.
5) Set voltometer for AC voltage. Place one probe of the voltometer on -120 and
the other probe on motor. See drawing(Page 3-5). Plug the lift into an outlet. Set
outriggers, turn on ignition key, and pull out both E-Stops. Press the common
and up switches on the upper control box.
a) Damaged or improperly connected motor
harness.
b) Damaged motor.
a) Circuit board damaged.
1a) Lift turns off and restarts in five
seconds.
1b) Outrigger lights turn on immediately
and no five second delay is present.
1) Lift will raise but will not lower. Turn on key switch, pull out both upper and
lower E-Stops. Press the common and down push buttons on the upper control box.
a) Low line voltage.
b) Extension harness excessive in length.
c) Improperly connected or damaged motor
harness.
d) Improperly connected or damaged coil
cord or upper control box.
e) Damaged down solenoid.
a) Continue to step 2.
LIFT DOES NOT TURN ON - AC
LIFT DOES NOT RAISE - AC
LIFT DOES NOT LOWER - AC
3.1