How do you release a chain hoist?
To lift the load, pull the hand chain (15) to rotate the handwheel in clockwise direction. When pulling the hand chain in the reverse direction, the handwheel will be separated from brake seat (10), the ratchet disc (14) checked by pawl (17) will be released, and the load will be lowered down smoothly.
Why is my hoist not working?
Possible Cause: (i) No voltage at hoist main line or branch circuit switch; branch line fuse blown or circuit breaker tripped. (ii) Phase failure, open circuit, grounded or faulty connection in one line of supply system (hoist wiring, reversing contactor, motor leads or windings).
How does a chain hoist clutch work?
Principle of operation of a chain hoist test set In order to check the release force of the friction clutch, the force transducer is hooked into the chain together with the appropriate adapter sleeve. Then they move upwards together against the bottom of the chain hoist and block the chain.
What is overload protection on chain hoist?
When the load exceeds a preset percentage of rated capacity (usually 100 to 125 percent), the overload protective device temporarily inhibits the hoist so that the crane can only lower the load. Chain hoist overload protective devices act like a car in neutral.
What is the difference between chain hoist and chain block?
Differences between lever hoist and chain blocks Lever hoist is operated using one hand by cranking the lever/ handle forward or backwards. Chain blocks are operated using hand chain. Chain blocks gives you the ability to lift very large loads up to 50,000 kg with ease by using mechanical advantage.
Can I use a chain hoist to pull horizontally?
(Hand) chain hoists, typically, can only be used vertically. If they are used to move the load horizontally, the chain will get jammed and gears inside can be damaged to shorten the lifespan.
How do you reset a hoist?
The emergency stop can easily be reset – this will be detailed in the hoist instruction manual, but often this can be reset by twisting the button, or by pulling the cord. This can vary from hoist to hoist, but is normally a very simple procedure, and is one of the most common reasons for call-outs.
What is chain pulley block?
A Chain Block (also known as a hand chain hoist) is a mechanism used to lift and lower heavy loads using a chain. Chain blocks contain two wheels which the chain is wound around. When the chain is pulled, it winds around the wheels and begins to lift the item that is attached to the rope or chain via a hook.
Can you overload a chain hoist?
Overloading The Hoist: Not surprisingly, the single most common way to potentially damage or misuse a chainfall is to overload the hoist. Flipping the hook on a double-parted chain hoist will twist the chain, and therefore, run the chain up into the hoist and jam the chain into the gears, causing many internal issues.
How does overload work?
Overload relays protect a motor by sensing the current going to the motor. When current is too high for too long, heaters open the relay contacts carrying current to the coil of the contactor. When the contacts open, the contactor coil de-energizes, which results in an interruption of the main power to the motor.
Can you use a chain block horizontally?
Chain blocks are portable devices used to manually lift or lower a load. Chain blocks are able to lift in a vertical position only. If they are side loaded or used horizontally it is possible for the mechanism to jam. How does a chain block work?
How does a chain hoist work and how does it work?
Lifting rotates the brake/clutch on the ratchet. Lowering releases the pressure on the brake via a multi-lead screw similar to a brake Bendix. These operate like the ratchet hoists above except a chain wheel and loop of hand chain turns the gearing. A brake holds the load and a ratchet prevents the brake from rotating one direction.
What causes a hoist to not lower a load?
Possible Cause: Load not lowered after hoist was used for lifting. Possible Solution: Unlock load brake. Hoist load brake slips (hoist will not support loads). Possible Cause: (i) Brake friction surfaces coated with oil or friction washers glazed. (ii) Brake parts damaged or worn. (iii) Load chain installed backwards.
What to do if your chain hoist is overloaded?
If the hoist is overloaded then reduce the load. If that is not the issue then check to see if the slip clutch worn or incorrectly adjusted. If so replace or readjust the clutch torque.
What causes a chain hoist to make strange noises?
If the load drifts more than 4 inches the brake lining may be worn and needs to be replaced. If the air gap on the brake is too wide, adjust the air gap setting. If the chain host makes strange noises while lifting or lowering, the chain may need to be cleaned and lubricated.