KS B 6220 Electric Hoist Safety Requirements: Standard Overview
Standard Overview: This standard specifies the general technical requirements for the safe operation of cranes, covering core safety elements such as safety device configuration, operator qualification, daily inspection, and periodic inspection. It constitutes a key component of the crane safety regulatory system in the country/region where it is applied.
Crane safety management is fundamentally about redundancy—any single safety measure can fail, and only a multi-layered safety protection approach can reduce accident probability to an acceptable level. This standard is built on a three-tier protection framework: safety devices, operating procedures, and inspection systems.
Safety Device Configuration Requirements
The standard requires cranes to be equipped with at least the following: a Load Limiter (alarm and hoisting cutoff at ≥100% overload), a Load Moment Limiter (LML) for jib-type cranes, a Hoisting Height Limiter (with dual redundancy of deceleration limit switch and limit switch), a lowering limit switch (to prevent wire rope reverse spooling), and an emergency stop device (red mushroom-head type ≥40mm, self-locking with twist-to-release, at least one per operating station). If any safety device fails to function, the crane must be shut down immediately for repair—operation with a faulty safety device is prohibited.
Safe Operating Procedures
Operators must complete specialized training and pass qualification assessments. A Pre-Shift Inspection is required before operation—functional testing of each safety device, visual inspection of the wire rope, hook opening measurement, and verification that the crane rail is clear of obstructions. During operation, the "Ten No-Lift Rules" apply: no lifting overloads, no lifting with unclear signals, no lifting improperly secured loads, no lifting with people on the load, no lifting with malfunctioning safety devices, no lifting buried objects, no lifting with angled pulls, no lifting sharp-edged loads without padding, no lifting in insufficient lighting, and no lifting in winds of Force 6 or above.
Three-Tier Inspection System
The standard mandates a three-tier inspection regime: Daily—operators perform visual and functional checks and record findings in the operation log. Monthly—maintenance personnel verify fastener tightening torque, insulation resistance, and limit switch calibration, with results documented in the maintenance record. Annual—a certified inspector performs a 125% static load test, a 110% dynamic load test, NDT sampling of critical weld seams, and a full functional verification of all safety devices, issuing a formal inspection report.
| Period | Performer | Content | Record |
|---|---|---|---|
| Daily | Operator | Visual Inspection/Functional Check/Abnormal noise | operation log |
| Monthly | Maintenance Worker | Torque/insulation/Limit Switch | maintenance record |
| Annual | Inspection Operator | Load Test+NDT | inspection report |
FAQ
Q: Can an overload limiter still be used if its deviation is too large?
A: No. The tripping deviation must remain within ±5%. Calibration is performed by loading the crane sequentially with test weights or a force sensor at 50%/75%/100%/110% of rated load and plotting the resulting curve. For a quick daily check: with an empty hook the reading should be ≈0, and a test block of known weight applied at the 50% load point should read within ±5% — anything beyond that indicates a problem.
Q: Can a crane keep running with a faulty component?
A: If any safety device fails, the crane must be taken out of service immediately. Non-safety items — a burned-out light, a cracked window, peeling paint — can be scheduled for repair. The judgment criteria are straightforward: stop immediately if personal safety is at risk; continue operation with a planned repair if performance is affected but safety is not compromised; schedule cosmetic fixes at your convenience. The operator has the authority to stop the crane — if in doubt, ask yourself "what's the worst that could happen if I'm wrong?" If the answer involves injury or death, stop the crane.
Q: Which matters more — inspection records or the inspection itself?
A: Both matter, but they serve different purposes. Inspection is the means — a thorough inspection produces reliable records. Records are the legal evidence — an inspection without documentation is legally the same as no inspection at all. A proper record must include: the problem identified, a severity classification, the corrective action taken (immediate / scheduled / monitored), and verification that the action was completed. If records repeatedly show "no abnormalities" while the equipment clearly has issues, the inspection process is just going through the motions.
Q: How do safety standards apply to non-standard cranes?
A: Use the risk analysis methodology of ISO 12100. The designer must identify every foreseeable hazard — mechanical, electrical, thermal, noise, radiation, materials, ergonomic — assess the risk level (severity × probability), and implement measures to reduce risk to an acceptable level. The entire process must be documented; this technical file is the core deliverable for passing a statutory safety review of a non-standard crane.
