JET VOLT-025-13P-10, VOLT-025-13P-15, VOLT-025-13P-20, VOLT-025-03P-10, VOLT-025-03P-15 Operating Instructions and Parts Manual

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Operating Instructions and Parts Manual

VOLTTM Series Electric Chain Hoists

JET

1/4 ton model shown

1.0 Warranty and Service

JET warrants every product it sells against manufacturers’ defects. If one of our tools needs service or repair, please contact Technical Service by calling 1-800-274-6846, 8AM to 5PM CST, Monday through Friday.

Warranty Period The general warranty lasts for the time period specified in the literature included with your product or on the official JET branded website.

 JET products carry a limited warranty which varies in duration based upon the product. (See chart below)  Accessories carry a limited warranty of one year from the date of receipt.  Consumable items are defined as expendable parts or accessories expected to become inoperable within a

reasonable amount of use and are covered by a 90 day limited warranty against manufacturer’s defects.

Who is Covered

This warranty covers only the initial purchaser of the product from the date of delivery.

What is Covered

This warranty covers any defects in workmanship or materials subject to the limitations stated below. This warranty does not cover failures due directly or indirectly to misuse, abuse, negligence or accidents, normal wear-and-tear, improper repair, alterations or lack of maintenance. JET woodworking machinery is designed to be used with Wood. Use of these machines in the processing of metal, plastics, or other materials outside recommended guidelines may void the warranty. The exceptions are acrylics and other natural items that are made specifically for wood turning.

Warranty Limitations

Woodworking products with a Five Year Warranty that are used for commercial or industrial purposes default to a Two Year Warranty. Please contact Technical Service at 1-800-274-6846 for further clarification.

How to Get Technical Support Please contact Technical Service by calling 1-800-274-6846. Please note that you will be asked to provide proof of initial purchase when calling. If a product requires further inspection, the Technical Service representative will

explain and assist with any additional action needed. JET has Authorized Service Centers located throughout the United States. For the name of an Authorized Service Center in your area call 1-800-274-6846 or use the Service Center Locator on the JET website.

More Information

JET is constantly adding new products. For complete, up-to-date product information, check with your local distributor or visit the JET website.

How State Law Applies

This warranty gives you specific legal rights, subject to applicable state law.

Limitations on This Warranty

JET LIMITS ALL IMPLIED WARRANTIES TO THE PERIOD OF THE LIMITED WARRANTY FOR EACH PRODUCT. EXCEPT AS STATED HEREIN, ANY IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXCLUDED. SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG AN IMPLIED WARRANTY LASTS, SO THE ABOVE LIMITATION MAY NOT APPLY TO YOU. JET SHALL IN NO EVENT BE LIABLE FOR DEATH, INJURIES TO PERSONS OR PROPERTY, OR FOR INCIDENTAL, CONTINGENT, SPECIAL, OR CONSEQUENTIAL DAMAGES ARISING FROM THE USE OF OUR PRODUCTS. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATION OR EXCLUSION MAY NOT APPLY TO YOU.

JET sells through distributors only. The specifications listed in JET printed materials and on official JET website are given as general information and are not binding. JET reserves the right to effect at any time, without prior notice, those alterations to parts, fittings, and accessory equipment which they may deem necessary for any reason whatsoever. JET

Product Listing with Warranty Period

90 Days – Parts; Consumable items 1 Year – Motors; Machine Accessories 2 Year – Metalworking Machinery; Electric Hoists, Electric Hoist Accessories; Woodworking Machinery used for industrial or commercial purposes 5 Year – Woodworking Machinery Limited Lifetime – JET Parallel clamps; VOLT Series Electric Hoists; Manual Hoists; Manual Hoist Accessories; Shop Tools; Warehouse & Dock products; Hand Tools; Air Tools

NOTE: JET is a division of JPW Industries, Inc. References in this document to JET also apply to JPW Industries, Inc., or any of its successors in interest to the JET brand.

branded products are not sold in Canada by JPW Industries, Inc.

2.0 Table of contents

Section Page

1.0 Warranty and Service ..................................................................................................................................... 2

2.0 Table of contents ............................................................................................................................................ 3

3.0 Safety warnings .............................................................................................................................................. 4

3.1 Important notice .......................................................................................................................................... 5

4.0 Product introduction ....................................................................................................................................... 5

5.0 About this manual .......................................................................................................................................... 5

6.0 Glossary ......................................................................................................................................................... 6

7.0 Dimensions of VOLT series hoists ................................................................................................................. 7

8.0 Specifications of VOLT Series hoists ............................................................................................................. 8

9.0 Unpacking ...................................................................................................................................................... 9

9.1 Contents of shipping container ................................................................................................................... 9

10.0 Installation .................................................................................................................................................... 9

10.1 Installing power and control cords ............................................................................................................ 9

10.2 Lubrication ................................................................................................................................................ 9

10.3 Chain container ...................................................................................................................................... 10

11.0 Electrical instructions ................................................................................................................................. 10

11.1 Grounding ............................................................................................................................................... 10

11.2 Variable frequency drive ......................................................................................................................... 11

11.3 Inspecting hoist motion ........................................................................................................................... 11

12.0 Pre-operation inspection .................................................................................................................................. 11

12.1 Inspecting load chain .............................................................................................................................. 1 1 

12.2 Inspecting hooks .................................................................................................................................... 12

13.0 Operation ................................................................................................................................................... 12

13.1 Controls .................................................................................................................................................. 12

13.2 Thermal overload protection ................................................................................................................... 13

13.3 Magnetic brake function ......................................................................................................................... 13

13.4 Optional pendant controls ...................................................................................................................... 13

14.0 Adjustments ............................................................................................................................................... 14

14.1 Replacing load chain .............................................................................................................................. 14

15.0 Inspection and maintenance ...................................................................................................................... 16

16.0 Inspection schedules .................................................................................................................................. 17

17.0 Allowable limits ........................................................................................................................................... 18

17.1 Hook wear limits (top and bottom) .......................................................................................................... 18

17.2 Chain wear limits .................................................................................................................................... 18

18.0 Brake adjustment and maintenance ........................................................................................................... 19

18.1 Brake adjustment ................................................................................................................................... 19

18.2 Periodic maintenance ............................................................................................................................. 19

19.0 Chain Containers for VOLT series Hoist .................................................................................................... 20

20.0 Troubleshooting the VOLT series Hoist ..................................................................................................... 21

21.0 Replacement Parts ..................................................................................................................................... 22

21.1.1 Exploded View for 0.25T to 5T Hoists (VOLT series) .......................................................................... 23

21.1.2 Parts List for 0.25T to 5T Hoists (VOLT series) .................................................................................. 24

21.1.3 Parts List for Top & Bottom Hook Assemblies, 0.25T to 5T Hoists (VOLT) ........................................ 29

21.2.1 Exploded View for 10-Ton Hoist (VOLT series) .................................................................................. 30

21.2.2 Parts List for Top and Bottom Hook Assemblies, 10-Ton Hoist (VOLT series) ................................... 31

22.0 Electrical connections for VOLT series Hoist ............................................................................................. 33

22.1 VOLT Hoist – 230V Single Phase .......................................................................................................... 33

22.2 VOLT Hoist – 230V Three Phase ........................................................................................................... 34

22.3 VOLT Hoist – 460V Three Phase ........................................................................................................... 35

3.0 Safety warnings

1. Read and understand the entire owner's manual before attempting assembly or operation.

2. Read and understand the warnings posted on the machine and in this manual. Failure to comply with all of these warnings may cause serious injury.

3. Replace warning labels if they become obscured or removed.

4. This chain hoist is designed and intended for use by properly trained and experienced personnel only. If you are not familiar with the proper and safe operation of a chain hoist, do not use until proper training and knowledge have been obtained.

5. Do not use this chain hoist for other than its intended use. If used for other purposes, JET disclaims any real or implied warranty and holds itself harmless from any injury that may result from that use.

6. Do not install this chain hoist where explosive hazards may exist.

7. Give your work undivided attention. Looking around, carrying on a conversation and “horseplay” are careless acts that can result in serious injury.

8. Do not use to lift people, or loads over people. Warn others in the vicinity when lifting or transporting a load. Avoid swinging load and hook.

9. Do not exceed the rated lift capacity of the chain hoist.

10. Make sure limit switches are operating properly. Do not use limit switches as routine operating stops; they are emergency devices only.

11. Verify that load chain is properly seated in load sheeve before operating hoist.

12. Do not use the load chain as a sling or wrap load chain around the load.

13. Always inspect the chain hoist for damage prior to use. Do not use a chain hoist with twisted, kinked, worn or otherwise damaged chain. If the chain hoist is damaged, do not use until it has been repaired or replaced.

14. Do not use more than one chain hoist to lift or move a load. If this is unavoidable, each chain

hoist must have the same capacity as the load to be moved.

15. Never allow the load chain to “set” over sharp edges. All lifts must be made with straight chain that is free of obstacles.

16. Do not use chain hoist unless load is centered between top and bottom hooks.

17. Protect load chain from weld splatter and other contaminants. Do not allow the hook or chain to be contacted by a live welding electrode.

18. Always take time to study the job to be performed and choose the safest method. Do not place yourself or other people in an unsafe position. Maintain constant awareness of the lifting environment.

19. Leave all internal maintenance to a qualified JET service center. Do not alter settings on the inverter. If its function is suspect, contact JET technical service for assistance.

20. Disconnect hoist from power source before performing maintenance or opening the housing.

21. Do not leave a suspended load unattended.

22. Replace the chain with factory replacement chain only. Do not use any other type of chain.

23. Never use the chain hoist if either hook is stretched, deformed, or has a broken or missing safety latch. Always replace the safety latch and/or the hook before placing the chain hoist back into service.

24. Keep safety guards in place at all times when the hoist is in use.

25. Do not operate this hoist while tired or under the influence of drugs, alcohol or any medication.

26. This hoist is not designed for exposure to outdoor elements.

27. Understand and follow all procedures as set forth in American National Standards titled Overhead Hoists (Underhung), ANSI/ASME B30.16. This standard is available through the American Society of Mechanical Engineers at www.ASME.org.

WARNING: This product can expose you to chemicals including cadmium which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to http://www.p65warnings.ca. gov.

Familiarize yourself with the following safety notices used in this manual:

This means that if precautions are not heeded, it may result in minor injury and/or possible

machine damage.

This means that if precautions are not heeded, it may result in serious injury or possibly even

death.

3.1 Important notice

It is the responsibility of the owner/user to install, inspect, operate and maintain this hoist in accordance with OSHA regulations and ANSI/ASME B30.16, “Overhead Hoists (Underhung)”, along with any state or local codes/ordinances as applicable. If hoist is installed as part of a total lifting system (trolley, crane, monorail, etc.), or if below-the-hook lifting devices will be used, it is the responsibility of the owner/user to comply with any standards or regulations involving those additional elements of the system.

4.0 Product introduction

Your JET variable speed hoist is designed and constructed to provide consistent, long-term operation if used in accordance with the instructions set forth in this manual.

JET VOLT hoists are available in 230 volt/dual phase; 230 volt/3-phase or 460 volt/3-phase configuration, as well as varied chain lengths.

The Variable Frequency Drive, or “inverter,” offers variable speed within a pre-established range. This allows lifting or descent of loads at reduced speeds without having to toggle the up/down button, thus providing efficiency and reducing stress on control contactors.

The magnetic disc brake provides dependable and rapid stopping of chain movement without hook drift, and produces less wear on brake elements than standard mechanical braking systems, thus reducing maintenance. The hoist is also provided with thermal overload protection and limit switches.

This hoist complies with ANSI/ASME B30.16 and HST-1 standards.

5.0 About this manual

This manual is provided by JET covering the safe operation and maintenance procedures for the JET VOLT series hoists. This manual contains instructions on installation, safety precautions, general operating procedures, maintenance instructions and parts breakdown for your hoist. It is not intended to be an exhaustive guide to the use of hoists or the broad subject of rigging, and cannot anticipate every system or lifting configuration in which this product may be used.

Retain all instructions and safety warnings for continued reference. If the hoist transfers ownership, the manual should accompany it.

If there are questions or comments, please contact either your local supplier or JET. JET can also be reached at our web site: www.jettools.com.

Read and understand the entire contents of this manual before installing hoist or

attempting operation, adjustment or maintenance. Failure to comply may cause serious injury.

6.0 Glossary

Creep speed: Slow, constant, fixed rate of motion of a hoist.

Duty cycle: The amount of work a hoist can perform in a given period of time, generally measured by maximum run time and number of starts within that period. Duty cycle ratings are designated H1 through H5.

Duty class: Identifies the type of service for which a hoist is designed, designated A through F.

Headroom: Minimum distance between saddle of top hook to saddle of load hook, measured when load hook is at upper travel limit. Smaller headroom allows a hoist to fit in tighter work spaces.

Hook saddle: The inside arc of the hook which contacts the beam (top hook) or where the load sling is seated (load hook).

Toggle or “bump fire”: Rapid press and release of a control button to raise or lower load in intermittent steps. (A variable frequency drive in lowest speed range often eliminates the need for toggling.)

Overtravel limit device: A device for limiting upward or downward travel of the load hook at the extremities of its lift. (If activation of the device alters the electrical circuit within the machine, it is often called a “limit switch.”)

Load block: The assembly of hook or shackle, swivel, bearing, pins, sheaves and frame suspended by the chain.

Magnetic disc brake: A stopping device controlled by the application of electrical current to the coil of an electromagnet, which draws away an armature allowing rotation of the shaft. When the magnet is de-energized, the armature moves back toward the brake face and squeezes together friction discs – the torque is applied to the hub and stops shaft rotation.

Overload limit device: A mechanical or electrical device that prevents the hoist from lifting when excessive load is applied.

Rated Load, or Capacity: The maximum load weight, usually labeled as tonnage, which the hoist is designed to handle as designated by the manufacturer.

Reeving: The system in which a chain or rope travels around a running sheave.

Running Sheave: A sheave which engages the chain/rope and rotates as the load block is raised or lowered. Also called “load sheave” or “load sprocket.”

Variable frequency drive (“inverter”): A control system that converts fixed line voltage and frequency into a three-phase system with infinitely variable voltage and frequency, in order to regulate motor speed.

7.0 Dimensions of VOLT series hoists

Figure 1: 1/4 ton to 5 ton hoists

C D a b d e g h i j

1/4 ton

1/2 ton

1 ton

2 ton

3 ton

5 ton

mm 505 610 626 286 317 309 31 142 102 415

in. 19.88 24.02 24.6 11.3 12.48 12.2 1.22 5.6 4.02 16.34

mm 505 610 626 286 317 309 31 142 102 420

in. 19.88 24.02 24.6 11.3 12.48 12.2 1.22 5.6 4.02 16.54

mm 550 630 666 286 317 349 38 142 102 430

in. 21.7 24.80 26.2 11.3 12.48 13.7 1.5 5.6 4.02 16.93

mm 605 780 694 430 336 358 45 185 165 487

in. 23.8 30.71 27.32 16.93 13.23 14.09 1.77 7.28 6.5 19.17

mm 605 780 694 430 336 358 45 185 165 487

in. 23.8 30.71 27.32 16.93 13.23 14.09 1.77 7.28 6.5 19.17

mm 665 870 694 430 336 358 61 240 110 665

in. 26.2 34.25 27.32 16.93 13.23 14.09 2.40 9.45 4.33 26.18

Table 1

Figure 2: 10 ton hoist

C D a b e g h i j k

10 ton

mm 1330 1068 715 892 358 90 365 365 1050 453

in. 52.4 42.05 28.15 35.12 14.09 3.54 14.37 14.37 41.34 17.83

Table 2

The specifications in this manual were current at time of publication, but because of our policy of continuous improvement, JET reserves the right to change specifications at any time and without prior notice, without incurring obligations.

8.0 Specifications of VOLT Series hoists

Table 3

Above stock nos. are representative. Custom chain lengths may be available – contact your dealer or JET. 2 50% Duty Cycle = maximum on time: 30 min/hr.; maximum number of starts: 300/hr.

Gross weight includes shipping/packaging materials.

40% Duty Cycle = maximum on time: 24 min./hr.; maximum number of starts: 240/hr.

9.0 Unpacking

Open shipping container and check for shipping damage. Report any damage immediately to your distributor and shipping agent. Do not discard any shipping material until hoist is installed and running properly.

9.1 Contents of shipping container

1 Electric chain hoist 1 Chain container with fasteners 1 Power supply cord 1 Pendant control cord 1 Operating instructions & parts manual 1 Product registration card 1 Test certificate

10.0 Installation

Support for the hoist may be hook, clevis pin, trolley, or beam clamp. Whatever method of suspension is chosen, the support components must be rated equal to, or greater than the capacity of the chain hoist. Supporting structures (such as I-Beams) should be installed by properly licensed professional installers.

If you are using the hoist with a trolley, refer to the trolley manual for instructions on securing the control cord and maintaining proper slack in the cord during operation. Optional pendant cords for use with a trolley system are shown in section

13.4.

Make sure the suspension system used is properly grounded, in addition to the grounding of the hoist.

10.1 Installing power and control

cords

Attach the power supply cord and control cord to the hoist as follows (see Figure 3):

1. Remove any protective caps from the plugs on the power and control cords, and from the sockets on the hoist.

2. Insert the 4-pin (4P) plug of the power supply cord into the 4P socket on the hoist. Insert the 7P plug of the control cord into the 7P socket. Orient the plugs properly; match the numbers on the pins in each plug to those in the socket. (The longest pin is the grounding pin, and should insert into the socket hole with the grounding symbol: ) Use sufficient force to ensure good connection.

3. Tighten the two cover nuts. Hand-tighten only; do not use a wrench.

4. The control cord has a cable loop to relieve strain upon the power cord connection. On 1/4- to 2-ton models, secure this loop by inserting it into the grooves of the clip, then installing clip to bottom of hoist with the two

screws. See Figure 4. On 3- to 10-ton models, secure the cable loop to the eyebolt on the side of the hoist.

Figure 3

1/4T to 2T 3T to 10T

Figure 4

10.2 Lubrication

10.2.1 Gear oil

Your hoist has been shipped with oil included in the gearbox. Before operating, verify the oil level by removing the plug on the side of the hoist (see Figure 5). The oil level should be just below the edge of the hole.

Figure 5

The oil in the gearbox should be changed annually, or more frequently under severe service, as follows.

Use either of these recommended oil brands:

Mobilgear XMP 100 Shell Omala S2 G 100

Capacities:

1/4T,1/2T,1T Hoists – 0.8 Liters (0.21 gal) 2T,3T,5T,10T Hoists – 1.5 Liters (0.4 gal)

To drain and refill gearbox (refer to Figure 5):

1. Open vent plug on top of hoist.

2. Open drain plug and drain reservoir. Reinstall drain plug.

3. Pour oil into fill hole.

4. Check level by removing side plug.

5. Reinstall top and side plugs.

10.2.2 Chain lubrication

Do not dump chain by hand

into the chain container! By not following the above steps, the chain can become twisted or kinked and can damage the hoist.

Figure 6

11.0 Electrical instructions

Periodically apply a light coat of 30W oil to the chain. This will create easier operation and prolong the chain’s life. For optimum results, clean chain with an acid-free solution before oiling.

10.3 Chain container

Your hoist is supplied with a chain container designed to fit the particular length of chain. If a different length chain is ever installed on this hoist, the chain container must be replaced by one of proper size.

The chain container should be installed after the power supply is connected to hoist. Refer to section 11.0, then proceed with the below instructions on chain container installation.

Do not overfill chain container.

If chain should overfill and begin to fall, entire chain container may empty without warning, resulting in serious personal injury or property damage.

To assemble chain container to hoist:

1. Hang hoist in position on the I-Beam or trolley. Do not install chain container yet. Allow slack side and load side of chain to hang freely from hoist.

2. Apply power to hoist and press DOWN button until limit switch is tripped.

3. Mount chain container to hoist undercarriage, using a short and a long bolt with lock nuts See Figure 6.

4. Place chain stop into container, and operate hoist to bring load hook up until upper limit switch is tripped.

5. Inspect chain to ensure that all non-loaded chain is completely in container.

Electrical connections must

be made by a qualified electrician in compliance with all relevant codes. This machine must be properly grounded to help prevent electrical shock and possible fatal injury.

The 230V hoists up to 1-ton are prewired for 3phase, but can be operated on either single or 3-

phase power supply. (The inverter will convert incoming single-phase power for proper delivery to the 3-phase induction motor.)

The 460V hoists and 230V 2-ton and larger hoists, are 3-phase only.

If an electrical plug (not provided) is installed on the hoist power cable, it must be appropriate for the phase used.

The hoist should be connected to a circuit with current overload protection, rated at 120% of the full load amperage listed on the hoist’s nameplate. If fuses are used, they must be time-delay fuses rated “D”. Local codes take precedence over recommendations.

11.1 Grounding

In the event of a malfunction or breakdown, grounding provides a path of least resistance for electric current to reduce the risk of electric shock.

This hoist is not supplied with a power plug. Power supply cables may either be fitted with a UL/CSAlisted plug rated for the appropriate phase and voltage, or “hard-wired” directly to a control panel. If hard-wired, make sure a disconnect is available for the operator.

If a plug is installed, it must have an equipmentgrounding conductor and a grounding prong. The plug must be plugged into a matching outlet that is

properly installed and grounded in accordance with all local codes and ordinances. Do not modify the plug – if it will not fit the outlet, have the proper outlet installed by a qualified electrician.

Improper connection of the equipment-grounding conductor can result in a risk of electric shock. The conductor with insulation having an outer surface that is green with or without yellow stripes is the equipment-grounding connector.

If repair or replacement of the electric cord or plug is necessary, do not connect the equipmentgrounding conductor to a live terminal.

Check with a qualified electrician or service personnel if the grounding instructions are not completely understood, or if in doubt as to whether the tool is properly grounded.

Repair or replace damaged or worn cord immediately.

11.2 Variable frequency drive

The inverter is not user-

serviceable. Any programming or service must be performed by qualified personnel.

The inverter contains high voltage elements that may retain a significant charge for several minutes after power is shut off.

This hoist uses Variable Frequency Drive, also called an A.C. Inverter, to provide infinitely variable speeds within the specified range. The inverter controls motor speed by varying the frequency of voltage supplied to the motor. This is especially useful for slowing a load as it nears drop point.

The inverter does not require any programming; it has been pre-programmed from the factory. With the possible exception of the reset button, the

buttons on the face of the inverter should never be pushed at any time. Use only the controls on

the pendant cord.

If you suspect a problem with the inverter or its settings, contact JET technical service at 1-800274-6848.

A lightning strike or power

surge may cause inverter failure. When hoist is not in use, disconnect power plug, or have a 3or 4-pole disconnect installed on the power side.

11.3 Inspecting hoist motion

1. Before closing circuit breaker and testing hoist,

check that wiring has been complete. If hoist cannot be observed when circuit breaker is closed, station an observer within sight of hoist to report any movement when power is applied. Be prepared to disconnect power if

hoist motor starts when power is applied – the hoist must remain motionless when power is applied. Find and correct any problems before continuing.

2. With no load on load hook, press UP button very briefly and observe hoist action. The hook should move upward.

3. On hoists with 3-Phase power supply, if the hook moves in opposite direction to that shown on control button, or if no motion occurs when UP button is pressed, then the power supply wires are incorrectly positioned.

Disconnect hoist from power, and switch any two of the three supply wires at the power source (excluding the ground wire). Do not

attempt to rewire the hoist circuit or pendant controls for this problem. Use the

same safety precautions when reversing two of the supply wires as was used when the wires were originally connected.

4. Reconnect power and test hoist movement again without load. Run hoist to maximum lifting height to ensure lift limiting devices are operating properly. Adjust speed knob throughout its range to test variable speed function.

12.0 Pre-operation inspection

12.1 Inspecting load chain

Clean chain with non-acidic solution, and carefully inspect entire load chain. Replace damaged chain before using hoist. See section 17.2 for maximum pitch allowed for chain length. If the chain exceeds this amount, it must be replaced.

Also replace the load chain if any of the following are identified:

1. Seriously rusted or cracked.

2. Marks on the chain surface are deeper than 5% of the link’s diameter.

3. Links are twisted or deformed.

4. Links are stretched too long or considerably worn on the surface, especially at points where links contact each other.

Never extend load chain by welding a second piece to the original.

Do not operate hoist with

twisted, kinked or damaged load chain. Do not splice load chain.

Check that chain does not twist along its length from hoist to hook. If twist is present on units with multiple falls, the hook has been capsized; it must be passed back through the chain loop to remove all twist in the chain.

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