Manitowoc 18000 - Page 288

Reference Only
TROUBLESHOOTING 18000 SERIVCE/MAINTENANCE MANUAL
10-10
Published 12-05-17, Control # 035-23
Problem 8
No load drum operation (drum 1, 2 or 3).
POSSIBLE CAUSES
Load drum brake not releasing; No voltage through control handle to controller;
No voltage out of controller to pump EDC; Node fault; Wiring or switch is faulty.
CHECKS
Check drum brake signal and pressure; Check drum handle command in problem direction; Check computer signal to
brake solenoid, pump EDC and motor PCP; Check pump and motor pressure; Check DOS items on DRUM screen.
Yes
No
Engine loads when moving problem handle in either direction?
Yes No
Yes
No
Is 24 volts present at corresponding brake solenoid
when handle is moved? (See Section 3 - Checking
Electrical Inputs/Outputs).
Yes
No
Move switch
to off position.
Repair or replace wiring or switch.
Consult dealer/factory.
When moving problem handle fully in both directions, does selected DRUM
screen read 0.5 to 2.4 volts in raise or 2.6 to 4.5 volts in lower direction?
Yes No
When moving problem handle fully in both
directions, does DRUM screen approach
100% pump control for each pump?
Yes
No
Is voltage at problem
handle more than 0
with handle moved?
Yes
No
Is there an operating or system fault when handle is moved?
Correct problem.
Yes No
Consult dealer/factory.
Is pressure at drum brake(s) and drum
valve(s) more than 300 psi (21 bar)?
Repair or replace
drum brake/valve(s).
Yes No
Is there only partial charge
pressure at drum brake(s)?
Replace system pump or
brake valve block at motor.
Yes
No
Set charge pump
relief pressure.
Manually stroke pump(s). (See Section 2 - Manual
Override Tests). Does pump(s) pressurize?
Is 0.1 to 2.0 volts present at pump(s) EDC?
Yes
No
Yes
No
Replace pump(s) EDC.
Repair or replace
wiring or consult
dealer/factory.
Replace control handle.
Isolate pump(s). Does manually stroked pump(s) pressurize?
Yes No
Repair or replace motor.
Repair or replace pump.
Is 24 volts available at brake switch.
Yes No
Repair or replace wiring.
Is 1 displayed after brake on load drum screen.
Consult dealer/factory
Is there 24 volts to brake valve(s) coil?
Yes
No
Repair or replace wiring.