Cables and cable jackets can be damaged by a number of causes and accidents, from digging near unmarked underground cables to damage during installation. There are different degrees of damage that can be inflicted upon an armoured cable, below we outline different techniques designed to repair damage to the cables primary (outer) sheath.
If the sheath or jacket of an armoured cable is damaged it is important to repair the sheath as soon as possible to prevent further problems such as moisture ingress.
Heat Shrink Repair Sleeves
Repairing a cable with a heat shrinkable repair sleeve is suitable for power cables at any voltage. The SWRS sleeve is adhesive lined and features a stainless steel, self-locking channel, providing corrosion protection to the cables armouring and water tight seal around the sheath.
Supplied as standard in 1 metre lengths, the sleeve and channel closure system can be cut as required to fit the application. A soft-flame gas torch is also required to heat the cable repair sleeve.
Self Amalgamating Tapes
Self amalgamating tapes can be used to repair smaller sections of damaged SWA cable. 3M Scotch Silicone rubber or 3M Scotch EPR self amalgamating tapes are available, depending the the cable type being repaired.
To use self amalgamating tape for sheath repair, first, the cable must be prepared, which includes wiping clean the area and making sure it is completely dry. The PVC sheath surrounding the damaged area should be roughened with a wire scratch brush or coarse emery cloth to reduce water ingress along the smooth surface of the undamaged sheath.
Be sure to keep any tools or sheath abrasion brushes or cloths clean, as any oil or grease contamination on the outer cable jacket will prevent proper bonding and cause early sheath repair failure.
Starting at least 30mm from the damage, wrap the tape around at an angle of about 30o and pull the tension on the tape to reduce the width by about 1/3rd as you wrap. The tape should be overlapped 50/50 as you go. Once you’ve covered one way continue 30mm past the damaged sheath area, then wrap the tape back the other way, alternating the angle of the application to oppose the first layer.
3M Scotch Cable Jacket Repair Tape 2234
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