The Ex-proof requirement
In areas where flammable gas, vapour or dust may be present, the equipment used must not produce sparks. This is a holistic design issue that concerns not only the crane's motor but its panel, junction boxes, controls, lighting, and even the wheel and hook material.
An Ex-proof solution cannot be designed without knowing the area's zone classification and gas/dust group. This information is found in the facility's explosion protection document.
The risk of a rarely-used crane
Power plant maintenance cranes are used only a few times a year. Paradoxically, this makes maintenance more important, not less: brakes that stay still for long periods stick, grease hardens, contactors oxidise, and the rope picks up moisture at a single point.
For these cranes, the maintenance schedule is tied to the calendar, not to operating hours, with periodic no-load runs performed regularly.
Typical applications
| Application | Key requirement |
|---|---|
| Explosive atmosphere zone | Ex-proof (ATEX-scope) design, certified components |
| Turbine / generator maintenance | High lifting height, precise positioning |
| Boiler room maintenance | Heat-resistant components |
| Low usage | Calendar-based maintenance, periodic no-load runs |
| Outdoor equipment maintenance | Gantry or semi-gantry, outdoor-rated equipment |
| Critical downtime | Spare parts stock and fast service agreement |
Frequently asked questions
Can a standard crane be converted to Ex-proof?
Generally no. Ex-proof requires certifying the entire design, not individual components. Converting an existing crane is often more expensive than a new one.
Who determines the zone classification?
It's defined in the facility's explosion protection document. Crane design follows the zone and group information in that document.