Electrical

Electrical / Automation.

Crane electrical troubleshooting, PLC and control panel work, joysticks, sensors, limit switches and remote controls.

Service line 04Hydraulic · Mechanical · ElectricalReport included

Crane control cabinet with PLC and relays — Control cabinet

01What we do

Modern deck cranes are controlled by a PLC, a handful of sensors and a cabin full of joysticks and switches.

Modern deck cranes are controlled by a PLC, a handful of sensors and a cabin full of joysticks and switches. When one input is lost the crane either stops or behaves oddly, and the crew cannot tell from the cabin whether the problem is a wire, a sensor or the program. Our electrical team traces the signal from the switch to the controller with the circuit diagram in hand.

We repair and replace joysticks, encoders, limit switches, load sensors, relays, contactors and power supplies, and we diagnose PLC faults on Siemens, Mitsubishi, Omron and similar controllers found on cranes. Where the original control system is obsolete we design a replacement that keeps the crane's safety functions and fits the existing cabin.

Automation upgrades include radio remote controls, load moment indication, anti-collision and slewing limit systems, and the wiring and commissioning that goes with them.

CranesTech technician repairing a joystick unit in a crane cabin high above the deck — Cabin · joystick repair04

What to send us

Crane make, model and the control system fitted (maker, PLC type if known)
Alarm text or fault code shown in the cabin
What was happening when the fault appeared
Electrical drawings if the vessel has them on board

Describe the job

02Scope

What the service covers.

The work items under this service line, as listed by our engineers.

01
Crane Electrical TroubleshootingSignal tracing, insulation and continuity tests, motor and power circuit checks, fault memory read-out.
02
PLC SystemsProgram back-up, fault diagnosis, I/O module and CPU replacement, parameter setting on crane controllers.
03
Control Panel MaintenanceContactors, relays, breakers, terminals and wiring renewed; panel cleaning, heating and sealing against moisture.
04
Joystick Repair / ReplacementCabin joysticks repaired or replaced with compatible units; calibration of ramps and dead bands.
05
Remote Control SystemsRadio remote control supply, installation and commissioning for deck and provision cranes.
06
Sensors / Limit SwitchesHoist, luffing and slewing limit switches, angle sensors, load cells and pressure transducers set and tested.
07
Automation System UpgradesReplacement of obsolete control systems, load moment indicators and display units.
08
Electrical Installation / CommissioningCabling, lighting, heaters and new equipment installed, tested and documented.
09
Liebherr Module / Card TestingLiebherr control modules and cards wired to a test display, with the CAN configuration read and the module checked before it goes back in the crane.

On the job

Photos from recent attendances.

Open Liebherr crane control cabinet with breakers, relays and controller modules — Liebherr control cabinet01

Liebherr control modules with multi-pin connectors and wiring — Liebherr modules02

Electric motor with a gear pinion on its shaft, on a pallet in the workshop — Electric motor and pinion03

Short video

A Liebherr control module on the test bench.

The module is taken out of the crane and wired to a test display. The CAN configuration screen lists every line and module, so a fault can be pinned on one card or on the wiring around it.

Replacement cards for these controllers can be slow to find. Testing first tells you whether you need one at all.

Liebherr module test

03Typical jobs

Faults we are called for.

01Crane stops with no alarm: broken wire at the slewing limit switch found by signal tracing and repaired.
02Joystick response erratic: potentiometer worn, joystick replaced and ramps re-calibrated in the controller.
03PLC fault after a power dip: program restored from back-up, failed I/O module replaced.
04Obsolete control system: replacement controller and cabin panel designed, installed and commissioned.

04Questions

Asked before the first visit.

Do you have the programs for the crane controllers?

We back up the program on the first visit whenever the controller allows it. Where the program is lost and cannot be obtained from the maker, we rebuild the control logic and commission it with the crew.

Can a radio remote control be added to an older crane?

Usually yes. The remote is interfaced with the existing control circuit or a new controller, and the safety stops are kept and tested.

Spare parts / equipment