Overhead Crane Installation & Commissioning: 37 Q&A
Overhead crane installation, commissioning, inspection, and acceptance cover 4 major stages—rail laying, equipment installation, load testing, and inspection & delivery—with 37 core Q&As. From rail span accuracy to main girder camber control, from static load test procedures to TSG inspection intervals, this guide walks through the entire technical workflow from installation to acceptance. All parameters are referenced from ISO 4301 "Key Clause Interpretations of the Crane Design Standard: Load, Structure, Mechanism, Electrical, and Safety Systems", FEM 1.001, and TSG Q7016-2016.
Installation & Commissioning: Full Process Overview
Crane installation, commissioning, and acceptance mark the critical transition from factory delivery to operational service, and the quality of this phase directly impacts equipment service life and operational safety. The installation and acceptance FAQs in Kelude's technical documentation are organized into four stages following the construction workflow: rail laying (span, levelness, joint accuracy), equipment installation (main girder, end carriage, trolley, electrical wiring), load testing (no-load, rated load, 1.25× static load, 1.1× dynamic load), and inspection & delivery (TSG periodic inspection, full inspection, annual examination). The sections below are grouped by stage, with each answer specifying the operational parameters and acceptance criteria for direct on-site reference.
| construction phase | core content | critical Acceptance Indicator | execution Standard |
|---|---|---|---|
| Rail Laying | Crane Railselection/span/Levelness/Joint | span±5mm/level L/1000 | ISO 4301 Crane Design Standard-2008 |
| equipment installation | Main Girdersplicing/End Carriage/Trolley/electrical | Camber L/700~L/1000/insulation≥1MΩ | FEM 1.001/14406 |
| Load test | no-load/rated load/1.25timesstatic load/1.1timesdynamic load | drop≤Hookposition1/100 | FEM 1.001 |
| Inspection & Delivery | TSG (Special Equipment Safety Technical Regulation)periodic inspection/annual inspection/Acceptance | Full inspection cycle: 2 years | TSG (Special Equipment Safety Technical Regulation) Q7016-2016 |
Common Crane Rail Installation Issues
Rail installation is the first step in crane assembly, and its accuracy directly determines the quality of bridge travel and the crane's service life. The core accuracy requirements are:
Rail Gauge Deviation — For spans S ≤ 22.5 m, the rail gauge deviation must not exceed ±5 mm; for spans S > 22.5 m, it must not exceed ±8 mm (per ISO 4301 Crane Design Standard, Section 6.2.3).
Rail Levelness — The maximum elevation difference across the full rail length must not exceed L/1000 (where L is the total rail length), with an absolute maximum of 10 mm. At rail joints, the vertical offset must be ≤1 mm, lateral misalignment ≤1 mm, and the joint gap should be calculated based on rail temperature using the standard formula (typically 2–4 mm at ambient temperature).
Rail Straightness — Measured with a theodolite or laser alignment system, the total straightness deviation across the full length must not exceed ±5 mm.
After rail installation, a gauge re-check should be performed with a measurement cross-section taken every 6 m along the rail length, recording both maximum and minimum gauge values. For detailed rail standards, refer to the Complete Gantry Crane Selection Guide.
Common issues include out-of-tolerance rail gauge deviation (requiring adjustment of rail clamps or re-installation when values exceed allowable limits — Kelude's technical team uses laser alignment systems to keep gauge accuracy within ±3 mm) and uneven rail elevation (corrected by adding stainless steel base plates at low points, with plate thickness ≤10 mm and width ≥ the rail base width).
Crane Equipment Installation Issues and Solutions
The equipment installation phase covers the assembly and commissioning of major components including the main girder, end carriages, trolley, and electrical system. Key considerations for main girder assembly: Camber — the mid-span camber should be L/700 to L/1000 (per FEM 1.001/14406), measured at the bottom cover plate at mid-span using the wire-pull method or a level instrument; deflection is strictly prohibited. End Carriage Installation — the diagonal difference between the two end carriages must be ≤5 mm to ensure straight bridge travel without skewing. Trolley Rail — gauge deviation must be ≤±2 mm, and the elevation difference at the same cross-section ≤2 mm. Electrical Wiring requirements: motor and control cabinet wiring must be correct and secure, grounding resistance ≤4 Ω, insulation resistance ≥1 MΩ (measured with a 500 V megohmmeter), and power and control circuits must use separate cables of appropriate specifications. After electrical installation, each circuit should be checked for wiring correctness and insulation integrity, and all protective grounding and equipotential bonding must be verified against design requirements. Power supply selection is another common question during installation — choose based on site conditions: conductor rail (ideal for long-distance, frequent operation), cable reel (for medium-to-short distances), cable festoon system (for high-speed operation), or low-voltage rail (for explosion-proof environments).
Crane Load Test Procedures and Requirements
The load test is a critical step for verifying the structural strength and mechanism performance of the crane. Per FEM 1.001, it is carried out in three stages:
| No-Load Test each mechanism under no-loadload spectrumshall operate respectively for not less than30minutes, check running smoothness and noise, each Limit Switchand reliability of safety device operation, Brake Brakingperformance. | Static load test first lift100%rated loadhold suspended10minutes, then load to1.25multiples of rated loadhold suspended10minutes.Acceptance Criteria: no permanent Deformation, drop≤Hookat lowest position Loadarea of1/100. | Dynamic Load Test loading1.1multiples of rated load, repeatedly Hoisting / Liftingand Loweringshall operate respectively for not less than3times, simultaneous operation Crane Bridgeand Trolley.check normal operation of mechanisms, Brakingreliable, control system sensitivity.Testinspect after Boltand Weld Seam. |
Crane Inspection & Acceptance: Common Questions Answered
Crane inspections fall into three categories: installation supervision inspection, periodic inspection, and annual examination. According to TSG Q7016-2016 Rules for Periodic Inspection of Lifting Appliances: Installation Supervision Inspection — Newly installed or overhauled cranes must pass supervision inspection by a special equipment inspection body before being put into service. Periodic Inspection — In-service cranes require a full inspection every 2 years (annually for metallurgical cranes with work duty classification A6 and above), plus an annual examination every 12 months. Inspection items include: technical document review (registration certificate, installation supervision report, maintenance records), metal structure inspection (main girder camber, weld seams, connecting bolts), mechanism and component inspection (brakes, wire ropes, hooks, pulleys, wheels), electrical system inspection (insulation resistance, grounding resistance, overcurrent protection, undervoltage protection), safety protection device inspection (overload limiter, height limit switch, travel limit switch, wind protection device), and load tests (Rated Load Test at 100% SWL). Any non-conforming items must be rectified and re-inspected; the equipment shall not be used until re-inspection passes.
Crane Inspection FAQ: Common Issues & Solutions
Q: What should be done if the crane rail span deviation exceeds the standard?
A: When the rail span deviation exceeds ±5mm (for spans S≤22.5m) or ±8mm (for spans S>22.5m), the rail clamps must be repositioned and re-secured. Procedure: loosen the rail clamp bolts, use a pry bar or rail alignment tool to shift the crane rail laterally to the correct position, then retighten the bolts and re-measure the span. If the deviation is excessive (>15mm), check the embedded parts and the installation accuracy of the runway beam. When multiple cranes share the same runway, the strictest span tolerance applies.
Q: What is the standard camber value for the main girder, and how is it measured?
A: Per FEM 1.001 (formerly FEM 1.001 and GB/T 14406-2011), the mid-span camber of the main girder should be L/700 to L/1000 (where L is the span). Measurement method: stretch a 0.5mm steel wire along the bottom cover plate of the main girder at mid-span, support both ends of the wire on equal-height blocks positioned on the end carriage centerline, then measure the vertical distance between the wire and the bottom cover plate using a steel ruler. Subtract the wire's dead-weight sag correction to obtain the actual camber. Negative camber (deflection) is strictly prohibited — if detected, immediate correction is required.
Q: What are the differences and procedures for static load test vs. dynamic load test?
A: Static Load Test: First, lift 100% of the rated load and hold for 10 minutes to measure deflection and lowering distance. Then, lift 1.25 times the rated load and hold for 10 minutes to check for permanent deformation. Acceptance criteria: no permanent deformation, and lowering distance ≤ 1/100 of the load-bearing area at the hook's lowest position. Dynamic Load Test: Apply 1.1 times the rated load and perform repeated hoisting and lowering cycles at least 3 times while simultaneously traversing the crane bridge and trolley, verifying smooth mechanism operation and reliable braking. Per FEM 1.001 (formerly FEM 1.001), the static load test must be performed first and pass before the dynamic load test begins. Kelude performs load tests on every crane before shipment following this exact procedure, with additional ultrasonic weld seam flaw detection.
Q: How are the timelines for periodic inspection and annual examination calculated?
A: Per TSG Q7016-2016, the annual examination is counted from the date the equipment is put into service, conducted every 12 months by the user's organization. The full periodic inspection is counted from the date the installation supervision inspection passes, conducted every 2 years by a special equipment inspection body. Metallurgical cranes with work duty classification A6 and above require a full inspection annually. The inspection date is based on the issue date of the previous inspection report — exceeding the deadline is not permitted. Any non-conforming items must be rectified and pass re-inspection before the crane can be returned to service.
Related Standards & Regulations
