When using an electric hoist in operation, strict control should be carried out in four stages: pre operation inspection, operation standardization, post operation maintenance, and special environment response. The following are specific precautions:

1、 Pre operation check: Ensure safe startup of the equipment

Electrical system inspection

Power supply and circuit: Check whether the power supply voltage matches the rated voltage of the equipment (such as 380V ± 10%), to avoid voltage fluctuations that may cause motor damage; Confirm that the power cord is not damaged or aged, and that the wiring terminals are securely fastened to prevent leakage or short circuits.

Control button: Test the sensitivity of the button to ensure that the "up", "down", and "stop" functions are normal, without any jamming or misoperation; The remote control equipment needs to check the status of the signal receiver to avoid signal interference and loss of control.

Grounding protection: Use a multimeter to measure the resistance between the equipment casing and the grounding electrode, ensuring it is ≤ 4 Ω; Check if the grounding wire is intact to prevent electric shock accidents.

Mechanical component inspection

Wire rope: Check whether the wire rope has broken wires, wear, rust or deformation. If the single strand breaks more than 10% or the wear exceeds 40% of the original diameter, replace it immediately; Confirm that the fixed end pressure plate of the steel wire rope is tightened, and leave no less than 2 safety rings on the drum.

Hook: Check if the opening degree of the hook exceeds the standard (≤ 15% of the original size), and scrap it if the torsional deformation exceeds 10 °; The hook anti detachment device (such as safety card) should be intact to prevent heavy objects from slipping off.

Brake: Manually test the sensitivity of the brake to ensure that the braking slip under rated load is ≤ V/100 (V is the stable lifting distance within 1 minute under load); Check the wear of the brake pads and replace them when the thickness is ≤ 50% of the original thickness.

Limiting device: Test the upper and lower limit position switches to confirm that the heavy object can automatically stop when it reaches the limit position; Do not repeatedly use the limiter as a travel switch to prevent equipment damage.

environment check

Homework area: Clean the tracks and ground obstacles to ensure smooth operation of the electric hoist; Check the straightness of the track and adjust it if the deviation exceeds 5mm to prevent derailment.

Safe distance: Confirm that there are no personnel staying within 3 meters below and around the suspended object to avoid heavy objects falling and injuring people; Set up safety nets or guardrails during high-altitude operations to prevent personnel from falling.

2、 Standard operation: Ensure safe operation of the task

load management

Overloading is strictly prohibited: Before lifting, check the weight of the heavy object and prohibit exceeding the rated load (such as lifting 6 tons of heavy objects with a 5-ton electric hoist); Stop the operation immediately when the overload limiter alarms, and lift again after reducing the load.

Uniform load: avoid unbalanced load or inclined pulling and lifting, and prevent uneven force on the steel wire rope from causing fracture; When lifting long heavy objects, a balance beam or double hook should be used to ensure a stable center of gravity.

operating action

Smooth lifting: First, jog and test lift (slowly lift 100mm), confirm the balance of the heavy object, and then proceed with the formal lifting; Prohibit emergency stop and start or frequent forward and reverse rotation to prevent motor overheating or brake wear.

Speed limited operation: The lifting and lowering speed must meet the design requirements (such as single speed electric hoist speed ≤ 8m/min), and overspeed operation is prohibited; The variable frequency speed regulation electric hoist needs to accelerate/decelerate according to the set program to avoid impact.

Prohibit personnel from lifting: It is strictly prohibited for personnel to stand on heavy objects or to lift and lower with suspended objects to prevent falling or crushing accidents; When multiple people are working, a dedicated person needs to command and unify the operation signals (such as gestures and whistles).

emergency response

Sudden malfunction: In case of emergency situations such as power interruption or brake failure, immediately press the "emergency stop" button to cut off the power supply; Slowly lower the heavy object to a safe position to avoid sudden drops.

Wire rope jamming: If the wire rope is found to be entangled or stuck, immediately stop the operation and check the status of the rope guide and drum; Do not forcefully drag to prevent wire rope breakage or equipment damage.

3、 Post operation maintenance: Extend equipment lifespan

Equipment reset

Raise the hook to a high position: After completing the task, raise the hook to a safe position (at least 2 meters above the ground) to prevent personnel collision or equipment deformation caused by heavy objects hanging.

Cut off power: Turn off the power switch of the control box, unplug the power plug (such as a mobile electric hoist) to avoid accidental starting or leakage.

Cleaning and maintenance

Cleaning dust: Wipe the surface dust of the equipment with a dry cloth to prevent dust from entering the electrical control box or mechanical components; Apply lubricating oil (such as lithium based grease) to the track, chain and other parts to reduce wear.

Check fasteners: Check whether bolts and nuts are loose, especially key parts such as motors, reducers, and brakes; Tighten loose parts in a timely manner to prevent equipment vibration from causing detachment.

Regular maintenance

Daily inspection: Check the status of steel wire ropes, hooks, brakes, limiters and other components before daily work, and record any abnormal situations.

Weekly inspection: Check the insulation performance of the electrical system (cold resistance ≥ 1M Ω), brake torque of the brake, and test the sensitivity of the overload limiter every week.

Monthly inspection: Conduct a comprehensive inspection of the equipment every month, including gearbox oil level, motor bearing temperature, track straightness, etc., and replace worn parts.

4、 Special environmental response: adapt to different working conditions

High temperature environment

Heat dissipation measures: Ensure good ventilation of the electric hoist during operations in high-temperature workshops such as metallurgy and casting; Install a cooling fan or fins on the motor to prevent overheating.

Shorten homework time: The continuous homework time should not exceed the rated load duration rate (such as M5 level electric hoist continuous homework time ≤ 10 minutes), to avoid motor burnout.

low-temperature environment

Preheating start: Before working in extremely cold areas (such as below -20 ℃), preheat the motor and reducer (such as wrapping them with heating belts) to ensure the fluidity of the lubricating oil.

Antifreeze treatment: Use low-temperature lubricating oil (such as synthetic grease) to prevent the lubricating oil from solidifying and causing the transmission components to jam; Install insulation layer on the electrical control box to prevent components from getting damp.

Damp/Corrosive Environment

Moisture proof sealing: In humid environments such as coastal areas and chemical industries, use electrical control boxes with a protection level of IP55 or above, regularly check the sealing strip status, and prevent moisture infiltration.

Anti corrosion treatment: Galvanizing or painting metal components (such as drums and hooks) to extend their service life; Wipe the surface of the equipment with a dry cloth after homework to avoid salt spray corrosion.

Flammable and explosive environment

Explosion proof certification: When using explosion-proof electric hoists in mines, chemical workshops, and other places, the electrical components must comply with GB3836 standards and obtain an explosion-proof inspection certificate.

Anti static measures: The equipment casing and metal structural components should be reliably grounded with a grounding resistance of ≤ 4 Ω; Operators should wear anti-static work clothes to avoid explosions caused by electric sparks.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment