Electric wire rope hoist

1, using a planetary gear reducer , high transmission efficiency , low noise , compact, intermediate shaft omitted, square appearance and easier mounting .
2 , lifting hook with a locking permanent magnetic lifter device to prevent accidental slippage rigging .
3 , the motor has a thermal protection device , when the motor temperature is too high , the device will automatically cut off the circuit to protect the motor is not damaged .
4 , The machine adopts cam limit , high limit accuracy.
5, high security and reliability : The machine optional load limit protection device , to avoid the adverse consequences caused by Lever Hoist overloading .

How to tell mini electric hoist performance

Mini electric  wire rope hoist  products workshop interior often use lifting tools, but also the home of choice for heavy lifting, mini electric hoist, small size, light weight facilitate installation, operation and lifting stability. Users at the time of purchase, according to the following distinguished miniature electric hoist quality and performance.
1, click the up and down keys to observe the running interval, the interval is smaller miniature gourd better.
2, mini electric hoist body shell or high strength die-cast aluminum body stretching.lever hoist Extrusion molding thin-walled precision manufacturing. Have an independent transmission system, sealed inside two coaxial transmission gear mechanism, the use of long-life oil bath lubrication system.
3, miniature gourd with DC electromagnetic disc brake, brake torque, smooth, fast, low noise.
4, mini electric  lift hoist  control after power up and down and move around, observe the arrow keys are accurate, running up and down at the same time pay attention to rest, is there a brake sound, while looking after repose, when there is decline in the chain, if so, that friction plate over loose, or not installed properly.

Electric hoist crane group conditions of use

Electric  rope hoist  crane group conditions of use
Conditions of use not only affects the group hanging electric hoist use and work efficiency, but also the life of the equipment has a great impact on the future, the following  for your group hanging electric hoist conditions of use.
     Electric hoist in what context the work efficiently for you to do the following brief introduction. If you do not pay attention to these factors the premise of their work, their work efficiency will be discounts. Many people use electric hoist, it may be the most easily overlooked premise of this factor in the working environment, but in fact the environment will affect their work.
Ambient temperature: -20 ℃ ~ +40 ℃
Work rail system: Intermediate JC25%
Weight class: JC40% when the intermediate rail system working group hanging electric  lever hoist  30% weight reduction, namely heavy duty rail system JC40% of electric hoist. Heavy duty rail system JC40% of electric hoist is used in relatively heavy work load often requires a higher safety factor rating or the case.
Electric hoist structure reducer: A three fixed idea helical gear roll structure, gears and gear shaft via a heat-treated alloy steel, box, cover made ​​from high quality cast iron, fitted tightly sealed. Reducer self-contained unit, handling is extremely convenient.
Control Box: The intercept in case of emergency the main circuit, and with vertical stroke limiter off the fire protection devices. Ensure the safe operation of the electric manual hoist. Electrical components, long life, reliable operation.

Electric wire rope hoist single multi reel

Electric wire rope  lever hoist  drum major play in lifting mechanism hoisting or hauling bodies and winding rope.
Electric hoist wire rope electric hoist drum where the number of layers can make single or multi-layered. Normally they use a single hoist drum. Single hoist drum surface is usually cut helical grooves, a rope wound in the groove, the contact area between the rope and the drum increases, the pressure reducing unit, and to prevent friction between adjacent wire, extending the life of the rope .
Spiral groove is divided into two kinds of shallow grooves and deep grooves, generally use more standard slots, only when there is the use of rope brackets dangerous only when using trench hoist drum. Single drum hoist pulley block with single spiral groove; twin pulley reel double spiral grooves symmetrically distributed.
Multilayer winding drum  manual hoist  for lifting height is large, while the electric hoist roll length and limited circumstances, such as cranes, electric hoist drum winding layers generally made smooth, and its inner rope by the outer layer extrusion wire in the winding process the friction between adjacent loops, reduce the life of the rope. Moreover, constant tension on the rope, the rope on the drum with the load torque varies layers, resulting in instability of the load torque. To improve the hoist wire rope on the drum in the released state, to improve the life of the rope,hoist equipment and there is also a spiral groove around the hoist multi-roll.

The smooth wire rope electric hoist

Wire rope lifting equipment as the main connectors, directly affects the quality of the use of equipment, at present, the domestic electric  chain block  is mainly used in glossy rope, the following details.
Smooth wire rope is usually caused by a few strands sub rope twisted around the core with a rope made ​​of crane and lifting operations are used in glossy rope round cross-section. Hemp rope core core material, asbestos core wire cores. Hemp core use most. According to the manufacturing process technology around the twist number of different bundles of wire rope can be divided into single rope around the twist, double twist around Smooth Smooth wire rope and wire rope triple twist around three categories.
Smooth double twist around the wire,lever hoist and wear resistance because of its moderate around, lifting up the dish operations are widely used. Double twist steel wire rope around the wire twisted into shares in accordance with the direction and strands twisted into rope F Shun to be divided into different rope around the smooth, glossy text wrapping around the bright wire rope and hybrid species.
        With electric hoist the increasing use of time, equipment except wearing parts, easily damaged wire rope part, to remind the majority of users, the use of electric wire rope hoist  to pay attention to the equipment before and after the inspection, if found damaged or abnormal parts, please replacement parts or contact the manufacturers to solve.

Chain hoists performance mutations cause decreased security

Chain hoists because of their small size and other simple maintenance and other advantages, the use of more extensive range of original, and because mutations chain hoists performance,lever hoist security incidents are growing decline, leading to the emergence of failures in addition to the device itself quality problems, the there are many objective reasons such as improper use of the following detailed analysis of your performance chain hoists mutations security reasons for the decline, for your reference:

1, chain hoists lifting weights over from the weight of the provisions;
2, chain hoists or oblique horizontal pull, pull too high or too low;
3, on the use of chain hoists lifting chain bend or kink is still used;
4, tossing hoists;
5, chain hoists main force component corrosion, cracks, lack of strength or significant plastic deformation;
6, rope or tie optional low base connection method is not correct, then do not tie securely;
Mutation  manual hoist  performance, safety performance reasons for the decline of the two
An opponent pull hoist performance principles, institutions are not familiar with easily removable;
2, install chain hoist brake, the installation is not reliable;
3, have not been unloaded after maintenance, overloading test that is put into use;
4, long chain hoists work load; work environment is complex, rubs increase the weight;
5, the use of chain hoists can not concentrate, resulting card chain, tripping, kink;
6, the use of the rear end routine maintenance, improper storage.
When you use a  chain Block  to remind eye rigorous inspection equipment for problems, operators work should concentrate, to observe, rational operation, after use to be more equipment to do proper maintenance to maintain a permanent chain hoists performance.

Flip method of construction hoist floating roof tank

In recent years, electric  wire rope hoist  is used for the construction of floating roof tank gradually frequently choose to use electric hoist for floating roof tank construction, because it is its applicability, especially electric hoist flip-law in this area to better highlight its advantages.

Flip electric hoist has obvious advantages and applicability, especially for floating roof tank construction, upgrading flip method is used 10,000 m3 external floating roof tanks, floating roof tank construction requires high maintenance inconvenience, under normal circumstances selecting slow smooth gourd work.
Electric hoist flip method is more secure, stable, easy to adjust, enhance each lap siding completed just 3-5min.hoist equipment No aerial, safe and reliable construction, welding tank wall were carried out on the ground, the boss low intensity, there is no need to use heavy lifting equipment (crane). Applicability of the construction without water restrictions. Easy control panel tank geometry deformation and ensure the accuracy, thereby ensuring the panel welding quality and avoid water-filled suits and other process is not conducive to control panel (especially thin) deformation of the shortcomings. Floating roof phased production, has little effect on the tank construction, ease of cross-operation of each process and pipeline operations, electric  lever hoist  flip method to improve the efficiency of labor and equipment, machinery efficiency.

Wire rope hoist brake selection to local conditions

Wire rope hoist brake is one of the essential parts, according to the wire rope hoist selection and use of environmental products and other practical needs to choose, the following detailed description of your brakes to choose how to do local conditions.

Wire rope chain Block  brakes must first consider the type and standard specifications, such as: lifting mechanism, luffing mechanism must be set to normally closed brake, walking or turning mechanism can be used normally closed brake.
Second, consider the use of premises, such as: Brakes installed there is enough space, the choice of block, arm band brake or disc brake, space is limited value, can be used within the shoe or clamp disc brakes.
Finally consider supporting wire rope lift hoist s used in the environment, there are strict requirements for oil leakage occasion use pneumatic brakes, the ambient temperature can be used insulation demanding high level of electro-hydraulic brakes. For special occasions, should be based on need for additional brake additional features. In the low temperature environment, you can use the electro-hydraulic thrusters of the heater. Conversion process for starting and braking when there are strict requirements, the installation of the brake limit switch for opening and closing state.wire rope winch For maintenance, adjustment difficult implementation environment, the installation of brake clearance balancing device and the friction lining wear compensation device. Additional manual brake device can be opened manually in exceptional circumstances brakes.
Wire rope  lever hoist  are many types of brake parts, the choice of when to use the environment to local conditions and other factors to consider, if you choose incorrectly, can damage the host, re-appeared personal risk and property damage.

Basic characteristics of small electric hoist

Small electric hoist people also known as "hanging miniature electric  rope hoist  ," and can only be fixed with the use of non trolley travel use. Its biggest advantage is small, economical use of space, the following details of small electric hoist basic features.
Small electric hoist as a new hoists are widely used in machinery manufacturing, electronics, automotive, shipbuilding, parts assembly, and high-tech industrial zone and other modern industrial production line, assembly line, assembly, logistics, transportation and other occasions. Especially for warehouses, docks, ingredients, hanging baskets and small work space narrower space operations, can show its advantages.

Small electric hoist basic characteristics are as follows:
     With emergency stop switch and reinforced breaking limit switches, protection class IP54,lever hoist with thermal protection device;
Freedom of movement Lightweight & compact design;
When the rope touches the limit arm, automatic stop upgrading;
Static and dynamic load sharing between activities set;
Operation on 220V household power;
Hook with safety lock 360 universal connector hook pad;
Small electric hoist or fixed column, wall-mounted jib crane "best partner." Which gourd beautiful appearance, reasonable structure, easy installation, low noise, especially suitable for workshops,chain block family, warehouses, hotels, shopping malls and other decoration and handling work.

How the selection, purchase electric hoist

Faced with a wide variety of standard models on the market electric hoist products, as the user how selection, purchase a suitable  rope hoist   Summarize the following need to consider when buying electric hoist factors hope for your help:
One, lifting height: electric hoist as a promotion tool, would lift height has strict requirements. Therefore, the time of purchase, you should first select according to plant height of lifting height, the conventional lifting height has 6,9,12,18,24,30 m.
Second, lifting speed: an ordinary electric hoist lifting speed is divided into single-speed (8m/min) and dual-speed (8/0.8m/min) two kinds, in the absence of special requirements are often used in the case of single-speed electric hoist also CD1 is the model number, if your condition requires heavy lifting required to pinpoint the course of the case, easy to use two-speed electric  lever hoist  MD1 model.
Third, buy electric hoist should pay attention to the spacing between the upper and lower hook, because in certain plant would hoist hook spacing specific requirements.
Four, motor power: Different electric hoist motors are not the same, the same 10t electric hoist motors may also be 13KW or 7.5KW, purchase according to their different needs.
V. Voltage: electric hoist wide field of application, involving all walks of life, so the use of the voltage will be different, there are 380V 220V China industrial electricity consumption, and even 440V, 60HZ, 380V, 60HZ series of non-standard power supply.
Six, mounting: electric hoist with electric trolley can be selected,hoist and trolley that is, up and down with the trolley hoist can lift heavy objects can be moved around, and can only be fixed up and down lifting heavy objects.
Seven, buy electric hoist electric hoist must consider carefully whether formal quality and manufacturers, the quality of the main factors to be considered: the motor, wire rope specifications, hook roll media. Manufacturers whether a formal main considerations: whether they have produced relevant documents crane, such as: production under license, certificate, etc.

Electric hoist brake problems how to deal with

Electric hoist brake failure is more common,manual hoist technical staff based on years of practice experience, brake failure is due mainly to a few points:
1, brake failure:
(A) the brake pads wear cladding serious or large loss;
(2) Long stroke solenoid is stuck;
(3) the moving core and the horizontal connecting rod between the lever off;
(4) electro-hydraulic thrusters or hydraulic solenoid does not operate;
(5) the main spring failure or damage;
(6) electrical failure and so on.
2, the braking force is insufficient.
(A) the brake pads or brake wheel cladding excessive wear;
(2) there are small pieces of cladding partial loss;
(3) the main spring tune too loose;
(4) Activities hinges which are catching or excessive wear of parts;
(5) caused by loose nut adjustment lever loose and so on.
3, the brake can not be loose brake.
(1) The hinge points are stuck not rotate;
(2) The main spring tension adjustment too large;
(3) electro-hydraulic thrusters lack of oil or hydraulic oil cylinder solenoid or air is not exhausted;
(4) coil or rectifier elements burning,lever hoist low voltage or line failure.
4, easy to disengage the brakes adjusted position.
(A) the main spring adjustment too loose;
(2) electro-hydraulic thrusters working stroke adjustment Debu meet the technical requirements.
These are on the main  wire rope hoist  brake failure, hope to help you.

Horizontal and vertical hanging hanging plate lifting clamp difference

    Plate lifting clamp called "steel clamp" is divided into two kinds of cross hanging and vertical hanging.wire rope hoist Cross hanging plate lifting clamp with horizontal distribution characteristics of lifting, lifting operations, the horizontal lifting clamp mouth pop, caught in the weight to be on the job, open, should weight the ground, the no-load case remove the steel clamp. Vertical lifting steel hanging clamp with self-locking device,lever hoist safe and reliable. Clamping speed, high efficiency. Rail clamp made ​​of high quality alloy steel, safe and reliable, fixed hanging beams, rail width adjustment quick and easy clip.
         Plate lifting clamp is mainly used in: railway, construction, metallurgy, ports, power, petrochemical, mining, automobile manufacturing, plastics machinery, pipelines and auxiliary set, slope tunnels, wells and control protection, salvage, ocean engineering, bridges, aviation, aerospace, venues and other important industries,manual hoist and infrastructure construction machinery and equipment.

Classification manual hoist

 Manual hoist lifting small in the most popular lifting tools, due to its own characteristics that make it easy to carry, so by the lifting industry's favor, manual hoist lever force can only be used as a power source for people not allowed use as a starting power than the lift. Can be divided according to type of manual hoist chain hoists and  lever hoist  two categories.
        In fact, if the environment in accordance with chain hoists scope can be divided into: ordinary chain hoists and chain hoists riot. Lever hoist Depending on the type and structure of the two main, wire rope and chain hoists chain hoist.
        Chain hoists and lever hoists are used to enhance the human heavy, not any longer operating handle; operation should let the rest handle freedom follower, not jamming. Must choose the appropriate size of the load tonnage gourd. Lever hoist applies to: shipbuilding, electric power, transportation, construction, mining, telecommunications and other sectors of the equipment installation, lifting items, mechanical retraction.  manual hoist   shell material is high quality alloy steel, extremely resistant, high safety performance. Chain hoists used in factories, mines, construction sites, wharves, docks,hoist and trolley warehouses and other places for installation of equipment, lifting goods.

Explosion-proof electric hoist large degree of common components, interchangeability

        Proof  wire rope hoist  used in flammable gas or vapor and air form explosive gas mixture. Explosion-proof electric hoist is mainly divided into three and four full-explosion-proof motor, explosion-proof electric hoist is disassembled by a number of components can be individually composed, the use of flexible, easy to maintain and repair is very convenient, and can shorten the repair time period, large degree of component commonality, interchangeability.
        Explosion-proof electric motor by a  lever hoist ,  explosion-proof control box, control buttons, and other related accessories are separate flameproof important structural composition. Explosion-proof electric hoist reducer standard modulus cylindrical gear, so ease of maintenance. Reel is running up and down lifting hoist rope to tighten up one of the most important parts. Guide rope helped  manual hoist  can be a good play to its superior performance. Explosion-proof hoist a large degree of component commonality, interchangeability.

Standard chain hoists safety rules

1 Normative references The following standards contain provisions which, through reference in this standard,chain block constitute provisions of this standard. At time of publication, the editions indicated were valid. All standards are subject to revision, and parties to this standard should investigate the possibility of the latest version of the following standards.
2 Scope This standard specifies the design of chain hoists, use, care and maintenance rules and standards for discarding the main components. This standard applies from the weight of 0.5-20 t, general purpose spur gear drive mechanism chain hoists, chain hoists other structures should also refer to types of use.
3, chain hoists general rules
3.1 each product must be accompanied by product use and maintenance manual, the production license tag and product certification.
3.2 product should have a clear,manual hoist durable signage.
3.3 non-overloaded crane lifting or diagonally. Prohibit buried in the ground or hanging pull condensation weight on the ground.
3.4 Suspension chain hoists supporting points must be solid, stable.
3.5 hanging, tied with a rope and chain safety factor shall be not less than 6.
3.6 is strictly prohibited under the rebate to the lifting hook lifting heavy chain
4, chain hoists using rules
4.1 Check before lifting
4.1.1 The parts must be intact, transmission parts and lifting chain oiled, empty running normally.
4.1.2 does not allow heavy hook hook hook tip.
4.1.3 Lifting chain is not twisted and knotted, double row chain hoists shall not be flipped to the next hook assembly.
4.2 Handling Precautions chain hoists
4.2.1 Operation should first try hanging, when the weight off the ground, and if the normal operation, reliable braking. Before continue lifting.
4.2.2 When operating above shall not stand heavy operation, nor place heavy objects lifted in the air after leaving the scene.
4.2.3 lifting process, and forbids any person to walk under the weight or stay.
5, chain hoists maintenance and repair rules
5.1 Daily inspection and maintenance
5.1.1 Check the lifting chain without excessive wear,lever hoist corrosion, deformation and external damage.
5.1.2 Check all rotating parts rotation is flexible, not loose fasteners.
5.1.3 Check the wear and deformation of the hook. Hook should be no cracks, sharp, burrs, corrosion, warping and twisting and other harmful defects.
5.1.4 the transmission parts should be regularly grease, brake friction surfaces must be kept clean and free of grease between, in order to ensure reliable braking performance.
5.1.5 Lifting chain lubricant coating should be used frequently and should not be tainted dirt and other debris to prevent people lifting belt sprocket and deposited in the cavity, affecting the normal engagement.
6, the main components of scrap chain hoists standard
One of the main components of the following conditions should be scrapped
6.1 Hook
a) section wear more than 10% of nominal size;
b) cracking;
c) dangerous section or neck plastic deformation;
d) hook mouth size deformation increases more than 15% of the nominal size;
e) torsional deformation of more than 10 degrees.
6.2 Lifting chain
a) Chain wear ring diameter than the nominal size of 10%;
b) 11 links from more than 3% elongation,hoist equipment the elongation from a single part of more than 5%;
c) cracks or other harmful defects.
6.3 Gear
a) tooth thickness wear more than 10% of the nominal size;
b) cracks; broken teeth

How to reduce the incidence of crane accidents

How to reduce crane safety incidents, as the crane inspectors, we think it should be from the following aspects: First,wire rope hoist as soon as possible (Amendment) comply with the current lifting machinery industry production, installation and use requirements and to adequately consider synchronized with the international common technical standards, such as "crane safety regulations" amendments should consider lifting mechanism brake control, adequate use of electrical braking brake assist feature to protect the brake.
    Second is to encourage co-production in our country and foreign lifting machinery, the introduction of advanced technology to improve the technological content of lifting machinery and safety performance and the overall level of manufacturing of lifting machinery.
    Third is to strengthen supervision and management of lifting machinery industry to crack down on illegal production and beyond the scope of lifting machinery. In terms of policy to those high-tech and high safety performance lifting machinery manufacturers tilted out or shutting down some of the low-tech, low-security,lever hoist carried out by low-cost competition in the market of enterprises, encourage enterprises to introduce lifting machinery manufacturing tech talent, especially the control aspects of personnel, on lifting machinery for a new concept of design.
    Fourth, strict quality supervision departments at all levels of operations personnel authorized training assessment, particularly the use of the Internal operational management skills to strengthen job training, highlighting the persons responsible for enterprise safety production responsibility system, strengthen the main person in charge of special equipment safety awareness, standardize operations personnel processes, enterprises engaged in special operations personnel to improve safety awareness and promote the implementation of the use of units lifting equipment at point inspection management.
    Five is due to its long-term supervision and inspection of lifting after the completion of the implementation of the supervision and inspection, the inspection according to the new regulations for the installation process of supervision and inspection of all inspectors to be changing attitudes, improve the professional level. Theoretically inspection regulations to strengthen the study and understanding and knowledge of manufacturing, the weak link in the installation process, in order to develop practical guidance documents for inspection work,manual hoist to ensure test quality. On this basis, for the previous installation of lifting machinery in the next periodic inspection process inspection regulations addition to routine inspections, but also targeted to check the installation, manufacture easy to bring safety hazards and defects link, increased use of advanced detection means test items necessary to prevent accidents.
    Six is ​​to advocate lifting machinery used in construction site supervision, inspection and supervision using communication barrier approach to management, to ensure that there are security risks of construction crane without rectification in place should not be allowed to continue to put into use.

Electric hoist lifting incident analysis

When using electric  rope hoist  lifting occurs during the broken teeth, broken shaft brake failure occurs, conventional electric hoist can play a protective role, accident consequences will be disastrous. In a safe braking torque and brake friction materials made ​​a trial, which will eventually help secure gateway has a very high reliability. Load protection overload protection is common, for some special circumstances, such as electric  lever hoist  for lifting or similar underground gondolas this condition, the required electric hoist crane being lifted can not occur on the rail car stuck or broken rope or fixed rope off phenomenon, it requires a super electric hoist, underrun protection. Electric hoist in cement and other building materials enterprises in the most widely used. Electric hoist mounted on the U-shaped multi-track. The cables are arranged in the middle of the track, the upper beam. Slip ring for the two rings linked together, there is a certain margin in order to avoid cable scratch cards. Put an end cap on the steering ring tightrope, leaving a good motor lead wire fixing rear rubber ring at the lower end of turn.chain block In the traction motor to turn to the center ring, pulling cable in a straight line or circular motion. If the electric hoist hanging objects from the car and run when improper methods, then make hanging objects swing accidents. Hanging objects lifting hoist, wire rope or chain tension when there should be parking, electric hoist according to the direction of the hook again to identify jitter hook, hanging objects should also be checked whether the hanging prison; electric hoist hanging objects runtime. By the person behind the electric hoist hanging objects help steady object and under the command of the rigger run around obstacles; electric hoist the runtime not intermittent,hoist equipment long-distance running, it is best to run a long power transmission.

Do not overload electric wire rope hoist operation

We buy it regardless of lifting products imported or brand, or some unknown manufacturers, must act according to certain rules, otherwise even better quality, but also very easy to damage danger, then the following to several people said  wire rope hoist  operation five elements of it.

1, the operation of lifting equipment must be a trained professional.
2 can not be manned.
3, can not throw things down from above.
4, can not collide with each other.
5, Do not overload.
Each lifting equipment are basic requirements of these points.
      Metallurgy electric  rope hoist  mounted on the beam orbit lifting heavy objects, and can make along the rail lines, curves reciprocating motion, to ensure adequate security. Adapted to the no fire, explosion and aggressive media in the work environment is suitable for lifting and transporting molten metal and in hazardous workplaces,lever hoist dual brake does not allow removing a brake use.

Two-speed electric hoist inspection before use

a. within walking distance of the operator's line of sight range, the weight should be no route through obstacles and floating debris.
b. Manual button up and down, left and right direction of action should be accurate and sensitive,lever hoist motor and gear should be no abnormal noise.
c. brakes should be sensitive and reliable.
d. electric hoist orbit should be no foreign matter.
e. vertical limiter action should be accurate and sensitive.
f. hook retainer nut should be tightened securely.
g. hook in the horizontal and vertical direction of rotation should be flexible.
h. hook pulley should be flexible rotation.
i. rope should be no obvious cracks,lift hoist neatly arranged on the roll, no disengage the pulley groove, chaotic twisting, folding clasp and other signs of good lubrication.
j. hanging aids no anomalies.
k. electric hoist working environment temperature -25 ~ +40 ℃
l. electric hoist does not apply to corrosive gases or relative humidity greater than 85% of the sites, not a substitute for proof hoist,Wire rope hoist not lifting the molten metal or toxic, flammable and explosive materials.

Damaged wire rope electric hoist treatment measures:

1 immediately press the emergency stop button to cut off electric hoist power;
2 Hoist and trolley Replace the wire rope (chain), and equipment overhaul;
3 Confirm the device without failure after continued use.
Rope damage prevention measures:
A rope used to meet the load capacity to carry the load,lever hoist prohibit the use of wire rope hoist direct bearing load;
2manual hoist using an appropriate hoist rated load;
3 timely replacement of excessive wear rope.