Overhead Crane Troubleshooting: Symptoms, Causes and Safe First Steps

Overhead crane troubleshooting starts with safety: stop the crane, set the load down if that can be done safely and lock out the power before anyone works on it. Faults usually lead back to supply and controls, protective devices, brakes, drives or wear. Below, each symptom is matched with likely causes and safe first steps.

Overhead crane troubleshooting begins with a safe crane

For every symptom, start here:

1. Stop the motion. If it continues after the button is released, press the emergency stop.
2. Set the load down slowly if this is safe; otherwise cordon off the area below and never leave the load unattended.
3. Clear the danger zone, report the fault and tag the crane as out of service.
4. Lock out and tag out before any work and verify that the crane is de-energized. Observe the discharge time stated on inverter drives, and keep other cranes on the same runway clear of the work area.
5. Leave repairs to qualified persons: electricians for electrical work, trained maintenance staff for mechanical work.
6. Never bypass or bridge a safety device such as a limit switch or the overload protection.
7. Never release a brake by hand under load unless the manufacturer's emergency procedure provides for it and a competent person carries it out.

A device that trips is reporting a problem – find the cause instead of resetting it repeatedly. Our guide to overhead crane safety devices explains what each one does.

The crane will not start or keeps losing power

The crane does not start at all

Possible causes: isolator or runway supply switched off; an emergency stop still pressed on the pendant, transmitter or crane; a blown control fuse or failed control transformer; a missing phase or wrong phase sequence, which trips the phase monitoring relay; on radio-controlled cranes, a flat battery or an unpaired transmitter.

First steps: Release all emergency stops and check the isolator – but never switch on one carrying someone else's lock or tag. Fuses, transformer and supply are for an electrician. After work on the supply or a motor, test each direction without load: if the hook moves opposite to the button, stop at once – the operating limit switches no longer protect.

Intermittent power or sparks at the current collectors

Possible causes: worn carbon brushes or weak contact pressure; dirty or misaligned conductor bars; a jammed towing arm; loose joints or feed connections; on festoons, a cable broken at a bend or a jammed cable trolley. Signs include contactors dropping out, inverter undervoltage faults and stops at the same spots.

First steps: Note where it happens. Arcing can start a fire and a poor earth contact is a shock hazard, so the crane stays out of service until an electrician has inspected the isolated line. Both systems are compared in festoon vs conductor bar.

The radio remote control does not respond

Possible causes: a flat battery; the transmitter's emergency stop pressed or start sequence incomplete; a transmitter not paired with this receiver; distance or radio interference; a damaged antenna or receiver. Stopping when the signal drops is intended behaviour.

First steps: Fit a charged spare battery, release the emergency stop, restart and stay within sight of the crane. Pairing and channel changes are for trained staff. Use only a transmitter labelled for this crane, and withdraw a damaged one.

Hoist faults: will not lift, load sinks, motor trips

The hoist lowers but will not lift

Usually a protective device is doing its job. Possible causes: the overload protection has tripped – load too heavy, still fastened or caught, or slack slings snatched at full speed; the hook is at the upper limit switch; the thermal motor protection has responded – on many hoists it blocks lifting but allows lowering; a missing phase, with the motor humming but not lifting; on chain hoists, a worn slipping clutch.

First steps: Lower the load, check weight and rigging, and take up slack at slow speed. If the emergency upper limit switch stopped the hook, the operating limit has failed – have the crane checked before further use. If the load is within capacity and hangs free, call service rather than retrying.

The load creeps down: hoist brake slipping

Stop using the crane – a slipping brake can let the load fall. Possible causes: a worn lining or an air gap outside the manufacturer's limits; oil or grease on the friction surfaces, often from a leaking seal; a fault in the brake supply or control that holds the brake partly open or applies it late. On inverter hoists, wrong brake timing shows as a brief dip at start or stop.

First steps: Clear the area, lower the load in a controlled way if possible, then lock out and tag the crane. Oil-soaked linings are replaced, not cleaned, and after the repair the brake is tested as the manufacturer specifies.

The motor overheats or its protection trips

Possible causes: more starts per hour or a longer operating time than the duty class allows – frequent inching, reversing at speed, long runs on the slow winding of a two-speed motor; a missing phase or low voltage; a dragging brake; stiff bearings, clogged cooling fins or hot surroundings.

First steps: Let the motor cool and do not keep resetting. A burning smell or a hot brake housing points to a dragging brake – call service. If the trips began when production increased, have the duty class reviewed; never raise the protection setting.

Travel faults: jerks, load swing and skewing

Jerky travel and swinging loads

Possible causes: two-speed motors on contactor control, which jolt at starting and at each speed change by design; on inverter cranes, ramps set too short or parameters lost after a drive replacement; worn coupling elements or gear backlash; harsh travel brakes; wheel slip on an oily rail; power interruptions at the collectors.

First steps: Note when the jerk occurs: at starting, speed changes, stopping or certain spots. Drive parameters are compared with the documented set and changed only by qualified staff. Where two-speed control is the cause, variable frequency drives are the lasting fix.

The crane skews and the wheel flanges squeal

Signs: one-sided flange contact, shiny rail edges, metal shavings. Possible causes: driven wheels of different diameters, often after a single wheel was replaced; one drive slower or braking harder than the other; rails out of tolerance in alignment, span or level; loose rail fixings; wheels or end carriages misaligned after an impact.

First steps: Report it early: skewing wears wheels and rails, loads the structure and is not cured by new wheels alone. Have wheels, drives and, if needed, the runway checked; if a flange climbs the rail head, stop the crane. Wear limits are listed in overhead crane wear parts.

Inverter fault codes and unusual noise

The frequency inverter shows a fault code

• Overcurrent: acceleration ramp too short, a brake not releasing, a mechanical blockage, a damaged motor cable or wrong motor data.
• DC-link overvoltage: while lowering or braking – a faulty braking resistor or chopper, or a deceleration ramp that is too short.
• Undervoltage: supply dips, a missing phase or poor collector contact.
• Overtemperature: blocked panel ventilation, a failed fan or clogged filters.

Note the exact code and what the crane was doing. Reset only as the manual describes – and not repeatedly. Encoder, overspeed or brake-monitoring faults on a hoist are safety-relevant – stop the crane and call service.

Unusual noise or vibration

Possible causes: low or contaminated gearbox oil, worn gears or bearings (growling, whining); a seized sheave or worn wheel bearing (squealing); a rope off its drum groove or a damaged rope guide (crackling, uneven winding); a dragging brake (grinding); loose bolted joints (knocks at start or stop).

First steps: Watch from a safe position and note which motion and load cause it. Noise from the hoist means stop: a rope out of its groove is damaged quickly and can fail.

When to call service – and what to tell them

Stop the crane and call service at once if the load sinks, a limit switch or emergency stop fails, the hook moves the wrong way, a rope, hook or structural part is damaged, there is smoke, sparking or a burning smell, or after a collision or overload. Have this ready:

• nameplate data of crane and hoist: manufacturer, serial number, year, rated load
• the symptom: which motion, with or without load, where on the runway
• fault codes and indicator lamps exactly as displayed
• photos or a short video taken from a safe position
• when it started, how often, and whether it is getting worse
• recent changes: repairs, new parts, electrical work, parameters, heavier loads, extra shifts

Keep a fault log for every crane – date, symptom, cause, action and name. Patterns soon appear: the same contactor, conductor bar section or brake.

Many breakdowns announce themselves – a lining near its limit, worn carbon brushes, a weeping seal – and daily checks, periodic maintenance and the statutory inspection by a competent person catch them early.

How Ervan Cranes helps when a crane breaks down

Our maintenance and technical support covers periodic maintenance, breakdown response and operator training. For repairs, we supply crane spare parts: wheels, wire ropes, hook blocks, brakes and control components. Ervan Cranes was founded in 2003 and manufactures in Torbalı, İzmir, and the team that designs the overhead cranes we build also commissions them on site.

Frequently Asked Questions

Why does my overhead crane lower but not lift?

Usually a protective device has responded – overload protection, upper limit switch or thermal motor protection – all of which block lifting but allow lowering. If weight, rigging and hook position do not explain it, have the supply and protective devices checked.

What should I do if the hoist brake is slipping?

Stop using the crane, clear the danger zone and lower the load in a controlled way if that is safe. Then lock out and tag the crane until a competent person has repaired and tested the brake.

Can the overload protection be bypassed for a single lift?

No. The Machinery Directive 2006/42/EC requires overload protection on cranes from 1,000 kg rated load. If it trips, the load is too heavy or wrongly rigged; a suspected faulty setting is checked by a competent person against the manufacturer's value.

Can our own staff repair crane faults?

Partly. Operators can handle simple checks: emergency stops, radio batteries, isolators, load weight. Electrics, brakes, hoists and safety devices are for qualified persons under lockout/tagout, with parts to the original specification and a function test afterwards.

Is a recurring fault holding up production, or do you need parts for a repair? Send us the nameplate data, a short symptom description and photos via our quote request form, and we will propose suitable parts or a service visit.