As a core representative of light and small lifting equipment, electric hoists, with their advantages of compact size, easy installation, and simple operation, have been deeply integrated into scenarios such as workshop transportation, warehouse loading/unloading, and equipment maintenance, becoming an “efficient assistant” in industrial production. However, their “light and small” characteristics also imply a lower safety margin. Once safety boundaries are breached, it can lead to equipment failure at best, or load drops and casualties at worst. So, what are the specific scenarios where an electric hoist absolutely should not be used?
The safe operation of an electric hoist primarily relies on “human compliance” and “management oversight.” When operator qualifications are lacking or management procedures are absent, even the most reliable equipment becomes a carrier of risk.
Regulations stipulate that electric hoist operators must obtain relevant operating certificates and be familiar with the structure, performance, and operating procedures of the equipment they operate. Unlicensed personnel, due to a lack of professional knowledge, are prone to “common sense errors”: such as mistakenly pressing the “down” button instead of “up,” causing the load to crash into the runway; or ignoring the prohibition of “side-pulling” (where the angle between the load and the hook’s vertical line exceeds 30°), leading to wire rope derailment.
Complex tasks (such as coordinated lifting with two hoists, lifting irregularly shaped objects) require synchronized operation and signaling. If there is no on-site signaler or if signals are chaotic, the operator may misjudge, causing the load to swing. Furthermore, if routine pre-shift inspections (checking the motor, wire rope, limit switches) are omitted, potential faults might be overlooked.
The safety of an electric hoist depends on the coordination of mechanical and electrical systems. Any failure or defect in components can break the safety balance. If the following issues are found before use, the hoist must be stopped immediately.
Mechanical components are the load-bearing “skeleton”; failure directly threatens load safety:
Wire Rope: According to regulations, use is prohibited if the number of broken wires exceeds 10% of the total wires in a strand, diameter wear exceeds 10% of the original diameter, or if kinking or severe corrosion (surface red rust) is present.
Hook: The hook must be scrapped immediately if visible cracks appear, wear on the dangerous section exceeds 10% of the original size, or the throat opening increases by more than 15%.
Brake and Gearbox: If the braking system exhibits “load creeping” (the load slips down more than the standard value when suspended), brake linings are excessively worn, or the gearbox leaks oil or produces abnormal noises, it indicates component failure.
The electrical system is the “control center”; faults can easily lead to loss of control or safety incidents:
Motor Abnormalities: Abnormal motor noises (e.g., “humming” or friction sounds), difficulty starting, or a casing temperature exceeding 70°C after 10 minutes of operation may indicate winding short circuits or bearing damage.
Wiring and Control Faults: Malfunctioning control buttons (e.g., pressing “up” causes “down” movement), damaged wire insulation (exposed copper), can cause short circuits or electric shock.
Safety Device Failure: Failure of the upper limit switch (preventing “over-hoisting”) or overload protection device is equivalent to losing the “safety valve.”
Indoor electric hoists often run on I-beam runways. Runway issues can cause derailment:Runway deformation (bending, sagging), misaligned joints (gap exceeding 2mm), or loose support bolts can cause the hoist to deviate during operation.
Electric hoists are designed with “stable loads” in mind. If the load’s weight, shape, or nature exceeds the adapted range, even perfectly maintained equipment cannot avoid risk.
The rated lifting capacity is the hoist’s “lifeline.” Motor power, wire rope diameter, and hook strength are strictly matched to this value. Overloading causes chain reactions: the motor draws excessive current, potentially burning the insulation and causing a fire.
Electric hoists are mostly designed with a “single hook + short wire rope,” requiring high load stability:
Loose/Bulk Loads Not Secured: Sand/gravel without (dedicated hopper), un-bundled rebar, which can scatter during lifting.
Irregular Loads Not Balanced: Oddly shaped machine parts, asymmetrical molds – if the center of gravity isn’t calibrated using auxiliary lifting gear, they will tilt severely after lifting, potentially hitting the runway or equipment.
Load Dimensions Exceed Limits: If the load’s own height + lifting height exceeds the distance from the runway bottom to the ground, the load may hit the ground.
Electric hoist electrical systems can generate sparks, and metal parts lack anti-corrosion design. If lifting hazardous materials without protection, use is strictly prohibited:
Flammable/Explosive Loads: Gasoline drums, paint cans – sparks from the motor could ignite leaking vapors.
Strongly Corrosive Loads: Acid/alkali solutions, electroplated parts – if leaked, can corrode the wire rope and hook.
Toxic/Harmful Loads: Pesticides, chemical intermediates – if packaging is damaged, toxic substances can volatilize, harming operators. The hoist lacks sealing to contain spread.
The mechanical and electrical components of electric hoists are sensitive to the environment. Standard indoor hoists lack design for harsh conditions. Use is strictly prohibited in the following environments:
Temporary outdoor work (e.g., construction site transport, open-yard warehouses) must be wary of weather risks:
Strong Winds: Wind speed exceeding 8.0 m/s (Beaufort Force 5) can cause outdoor hoist loads to swing, potentially displacing the runway.
Rain/Snow/Damp Conditions: Standard hoists typically have an IP44 rating (splash-proof). Moderate rain/heavy snow can allow water ingress into the motor/control box, causing short circuits or electric shock.
Thunderstorm/Heavy Fog: Outdoor hoists lack lightning protection – a strike on the runway can damage the motor/VFD. In heavy fog (visibility below 50 meters), operators cannot judge load position, increasing collision risk.
Extreme environments accelerate component aging/failure:
High Temperature (above 40°C): Motor cooling efficiency drops. Temperatures exceeding 155°C trigger过热保护 (overheat protection); frequent triggering accelerates winding aging.
Low Temperature (below -5°C): Gearbox lubricant thickens, causing lifting hesitation and potential motor slip.
High Dust/Humidity Environments: Dust in cement/flour mills can enter motor bearings and gearboxes, causing “dry grinding,” which can wreck bearings within a month.
Electric hoists are not “universal tools.” When task requirements exceed their capabilities, more suitable equipment should be chosen instead of forcing their use.
Electric hoists start/stop in a “jogging” manner, making millimeter-level adjustments difficult. For final positioning during installation of precision machine tools or optical equipment, using a hoist can cause misalignment or impact damage due to swaying.
If only moving small items (e.g., 50kg parts) short distances within a workshop infrequently, using an electric hoist might require permits and clearing the area, reducing efficiency. Using a hydraulic pallet truck, hand chain hoist, or manual handling (within safe weight limits) might be more flexible.
“Never stand under a load” is an ironclad rule. If the work area cannot be cordoned off with warning tape/signs to exclude unauthorized personnel, or if the load’s path crosses personnel walkways, lifting is strictly forbidden.
The “scenarios prohibiting use” for electric hoists essentially represent a safety adaptation to their characteristics of being “light, small, electrically driven, and used in specific scenarios.” Unlike the higher risk tolerance of large cranes, their motors, wire ropes, and runways are more susceptible to minor influences. Any small oversight can lead to an accident. In practice, misconceptions like “small equipment is safe” or “simple operation means casual use” must be abandoned: never skip inspections due to familiarity with the scene, never exceed the rated load due to tight schedules, and never violate rules like side-pulling based on experience alone.
We have 34 years of manufacturing experience and 12 years of export experience,business covers over 100 countries and regions worldwide, including Asia, Europe, America, Africa, and Oceania, forming a global product sales network.Received ISO system certification and CE product certification!
Our main products include 6 series of nearly 100 varieties, including electric hoists, electric winches, gantry cranes, bridge cranes, marine cranes, and jib cranes.
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