This document describes the procedure of jointing of wires in the project, and to ensure that all concerned persons are familiar with the sequence of activities, utilization of resources, and execution of the works in compliance with applicable Safety and Quality Procedures, and Project Documents and Specification. Following equipment and tools shall be arranged:
- Tool Box.
- Crimping Tool
- Heat Gun
- Wire Cutter / Crippler
- Measuring Tape.
- Step Ladders
- Knife / Cutter
- Hand Gloves
Necessary measures will be taken for the safety of the equipment and any other works affected by the works subject of this document. Relevant entities which might require protection include any such works in the vicinity of the area of work or on the service access or discharge path. The construction team will ensure that any such requirements are documented.
Simple and Detailed Work Sequence
- Select Tin Coated Copper Ferrule as per the cable size.
- Clean the wire and splicing as per the size of the ferrule.
- Insert the copper leads inside the ferrule and make sure no lead is outside the ferrule and cut length of copper lead is exactly matching with ferrule length.
- Crimp the ferrule by adjusting the correct size in the crimping tool.
- Crimp firmly and make sure that the joint is mechanically strong by pulling.
- Cut the heat shrink sleeves according to the length of ferrule with 4cm overlap and pull it on the cable.
- Now crimp other part of the joint as mentioned above.
- Now pull the approved heat shrink sleeve over the ferrule with 2cm overlap on both sides.
- Apply heat using a heat gun at recommended temperature i.e. 45oC to 125oC until it shrinks properly with ferrule & wires.
Alternate Method Statement for Termination using Hand Crimp and Screwed Terminal for Cables
The final destination of the cores of each cable shall be obtained from the Connection Schedule. Using this information the cores shall be routed in looms to their appropriate terminals. At this point the core will be measured, cut and ferruled in such a manner that a core entering a terminal from the left or right side shall have the ferrules installed so they may be read from left to right, irrespective of the core terminal entry.
Method of hand crimping/terminal screw insertion (Less than 35mm Sizes)
Obtain the correct termination crimp for the termination code, terminal type and core size. Using the correct crimping tool for the crimp, squeeze the tool handles until the ratchet releases and the tool opens fully.
Place the crimp in the tool crimping jaws so that the crimp tongue is located properly in the locator head. Squeeze the tool handles until the crimp is held firmly in the tool crimping jaws. Do not deform the crimp barrel. Insert the stripped wire fully into the crimp barrel.
On un-insulated crimps ensure that the wire insulation does not enter the wire crimping barrel. Hold the wire in position and complete the crimping operation by squeezing the tool handles until the ratchet releases. The crimped connection is then inserted fully into the equipment terminal and the terminal screw tightened firmly with a suitable size of screwdriver.
Crimping & Cable Lug Insertion
Obtain the correct conductor compression lug for the termination code specified on the Cable Card and check that the reference number on the lug is correct for the size of cable being crimped. Temporarily fit the lid in its position on the equipment terminal.
Position the cable core as near as possible to its final position through the center line of the lug socket and mark the core so that when cut the conductor will fully occupy the internal socket of the lug. Cut the core squarely to the mark.
Note: When using compression lugs a certain amount of creep is liable to take place and this must be compensated for when cutting the core to length.
Each terminating operative is to carry out a test with a short length of cable and the appropriate lug to establish the anticipated creep using that particular compression tool. The creep is to be registered against that tool and dies for consideration in all subsequent terminations.
Strip the core insulation back from the conductor by an amount that when assembled and crimped a gap of 10mm is left between the end of the lug and the core insulation. Deburr and straighten the end of the core until it enters freely into the crimping socket. Check that the end of the core is visible through the lug inspection hole.
Crimping the Termination (35mm to 500mm Cable Cross Section)
Unscrew the pedal beam retaining screw on the hydraulic foot pump. (This screw locks the pump beam in the horizontal position, making it convenient carrying handle). Remove the protective cap from the male half of the coupling hose and the similar cap from the female coupling on the crimping head. Screw the 2 together hand tight with the loose knurled nut on the female coupling. Ensure that the mating pats are free from grit or dirt.
Fit the correct compression lug onto the cable core with the palm at the correct angle. Select the correct crimping dies for the lug size and locate them in the crimping head. Check that the crimping code stamped on the dies is identical to that stamped on the lugs.
Close the manual valve at the side of the pump head. Do this firmly by turning the valve knob clockwise by hand.
Hold the crimping head in position on the cable lug ensuring that the crimping portion of the dies is placed centrally on the crimping barrel of the lug. Operate the pump until the cable lug is lightly gripped.
Ensuring that the lug does not move on the cable core during the crimping operation, operate the hydraulic foot pump until the crimping dies are closed. Full closure is indicated by an audible “click” as the overload valve operates and the pressure against the pedal beam is released.
Once the crimping operation is completed, open the manual valve at the side of the pump head. Once the lower die in the crimping head has retracted sufficiently, lift the crimping head off the crimped lug.
NOTE: When making repeated crimps of the same size of cable lug it is convenient to open the manual valve for only as long as it takes the lower crimping die to retract sufficiently for withdrawal of the crimping lug. This saves pumping time during the next crimping operation.