Vague safety scope
Replace "standard safety devices" with named devices, ratings, motions covered and test evidence.
For buyers and maintenance teams checking crane safety scope
EOT Crane Limit Switch and Overload Protection Guide
Know what to ask for, compare and test before accepting vague words like "standard safety devices included" in an EOT crane quotation.
Quick answer
A crane safety-device schedule should identify which motions are protected, the device type and make, trip or stopping behavior, reset method, bypass protection, test method and acceptance evidence. At minimum, buyers should clarify hoist upper/lower limits, travel limits, overload protection, emergency stop, isolator, warning devices, buffers and any anti-collision requirement.
Immediate value
What this guide helps you prevent
Bypass risk
Ask how limit switches, overload protection and emergency stops are wired, reset and protected from unsafe bypass.
Commissioning surprises
Define FAT/SAT checks before dispatch so site acceptance is not reduced to a visual inspection.
RFQ safety schedule
Safety devices to ask suppliers to define
| Device | What to ask in quotation | Acceptance check | Red flag |
|---|---|---|---|
| Hoist upper limit | Type, make, operating stage, backup/final limit if provided, reset method. | Verify hoist stops before hook block or load path becomes unsafe. | Only "limit switch included" stated. |
| Hoist lower limit | Whether lower travel limit is provided, drum-wrap reserve and operating logic. | Verify safe lower stopping point and rope wraps retained on drum. | No lower limit or drum-wrap statement. |
| Cross/long travel limits | Limit type, end-stop relation, approach speed and stopping behavior. | Test travel motion stops before buffers/end stops under controlled conditions. | Mechanical end stop treated as the only protection. |
| Overload limiter | Sensor type, set point, display/indication, calibration and trip action. | Verify calibration record and functional test at defined load or method. | No certificate, no trip setting, no test method. |
| Emergency stop | Locations, reset behavior, control category where applicable and covered motions. | Confirm E-stop stops intended motions and requires deliberate reset. | E-stop not tested during SAT. |
| Warning devices | Hoist/travel alarms, beacon, siren, overload indication or fault display. | Check visibility/audibility in the operating area. | Alarm scope left to site after installation. |
| Anti-collision | Required only when multiple cranes or collision risk exists; ask type and coverage. | Test approach, slowdown and stop logic where included. | Multiple-crane bay quoted without collision philosophy. |
FAT and SAT checks
What to test before final acceptance
Before dispatch / FAT
- Safety device list matches quotation and drawings.
- Limit switch makes, wiring and adjustment points are visible in documentation.
- Overload limiter certificate or calibration basis is provided.
- Control panel drawings show safety-device terminals and logic.
- Vendor confirms test method for each device.
At site / SAT
- Hoist upper/lower limits work at safe approach speed.
- Travel limits stop motion before unsafe impact.
- Emergency stop is tested from each operator station.
- Overload device indication/trip is verified using agreed method.
- Bypass, jumper or disabled safety devices are not left in service.
Copy-ready message
Vendor clarification wording
Send this when a supplier quotation says only "standard safety devices included."
Safety boundary: This page supports procurement and maintenance planning. Final safety design, statutory requirements, inspection, load testing and return-to-service decisions must be confirmed by competent personnel, vendor documents, site rules and applicable standards.
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