15.3 Air and Electric Hoists: Supply, Duty and Controls

Powered operation adds supply requirements

Air hoists use compressed air to drive their mechanism. Electric hoists use a specified electrical supply and controls. Both require adequate rated capacity, suitable suspension, correct chain or rope, travel range and manufacturer-supported operation. The power source does not change the need to calculate load and verify every connection.

Choose equipment for the required speed and precision, duty, environment and control method. A fast production hoist may be unsuitable for a delicate placement if its permitted controls cannot provide the needed movement. A light portable hoist may have a duty limitation that matters in repetitive lifting. Catalog capacity alone is not a complete selection.

Air-hoist selection

An air hoist needs the specified pressure and flow at the hoist. A compressor’s nominal rating at its outlet does not prove the pressure remains adequate after long hoses, restrictive fittings or simultaneous tool use. Inadequate supply can affect speed, control and operation.

Check hose size, connections, filtration, lubrication and water-control requirements from the manual. Do not assume every air hoist uses the same pressure or that increasing supply above the specified range is permitted. Higher pressure is not an authorized capacity increase.

Air-powered equipment is not automatically approved for every explosive or hazardous environment. The hoist’s materials, controls and any spark-resistant or hazardous-location provisions must fit the actual classification. A motor without an electrical cord does not remove mechanical sparks, static or other ignition considerations.

Verify pendant or control operation, emergency stop where provided, brake or load-holding function and the approved response to loss of air. Do not assume every system holds identically after supply failure. The manufacturer’s procedure and planned contingency establish what operators must do.

Electric-hoist selection

An electric hoist needs the correct voltage, phase, frequency and other specified supply conditions. Improvised extensions, damaged cables or unsuitable controls can create electrical and operational hazards. Installation must meet the equipment instructions and applicable electrical requirements through qualified personnel.

The duty rating describes permitted operation over time, not just one load’s weight. Frequent starts, extended running or repetitive near-rated lifts can overheat equipment beyond its intended duty. Select the product for the actual cycle rather than assuming all same-capacity hoists can work continuously.

Check controls, travel limits, overload devices where provided, brakes and emergency-stop functions under the manual’s inspection procedure. Limit switches are not ordinary operating targets to strike repeatedly. A failed safety or control device requires the applicable out-of-service response; bypassing it is not a way to complete the lift.

Common force-path checks

Both types need an approved upper support and lower rigging. Include equipment deadweight in the support demand where applicable. A trolley installation also requires beam and wheel compatibility. The rated hoist does not independently approve the runway or clamp.

Keep the load chain or rope straight and correctly reeved. Do not wrap it around the load as a sling, side pull against an obstruction or use the mechanism to drag a load in an unapproved direction. Unexpected resistance can indicate a snag, alignment problem or insufficient capacity.

Supply scenario

An air hoist operates slowly after another crew connects several tools to the same air line. The operator should stop safely and verify supply and operating conditions. Raising compressor pressure beyond the hoist limit or pulling the payload by hand while operating the hoist is not an approved remedy.

For an electric example, repeated lifting trips a protective device. The correct response is assessment of duty, supply, load and equipment condition by authorized personnel. Resetting repeatedly or bypassing protection can conceal the cause and expose the load to loss of control.

Operation and isolation

Take slack slowly, verify seating and conduct the required functional and trial checks. Keep personnel clear and maintain effective signals when required. Controls should command deliberate movement rather than sudden repeated starts that shock the system.

Before maintenance, follow the applicable isolation and lockout/tagout procedures. A stopped pendant does not establish that stored pressure or electrical energy is isolated. Operators should report defects and place equipment out of use through the prescribed process, not repair a loaded mechanism.

After stable landing, release and remove gear safely. Inspect for new damage and store or park the hoist according to its manual. The complete powered system must remain identifiable, maintained and suitable for the next task.

Sources: CCO powered-hoist topics, CMCO hoist manuals, CMCO equipment catalog.