Risk Assessment & Safe Working Practice

Transcription

1 RA Ref Number: 46 Revision: 3 Project/Job Number Reference Insert Job Number Approval Date: 30/03/2018 RA Description: Electrical Termination Pyro Next Review Date: 01/04/2019 Notes: Please refer to Safe Working Practices 46 for definitions of items in this assessment. Created by: Lee Davies Risk Assessment Method & Scoring The summary risk assessment is calculated as Likelihood x Consequence and categorised as follows; 1 to 6 = 7 to 16 = Medium Risk 17 to 25 = Issued by: Issue Date: Insert Name Insert Date TASK HAZARDS PERSONS AFFECTED INITIAL RISK LEVEL CONTROL MEASURES REVISED RISK LEVEL Stripping back of insulation on cable. Preparing cable for termination. Termination of Pyro to a distribution board. Cuts to hands / legs from sharp tools. Cuts from sharp conductor ends, sharp jacket edges. Electrician Likelihood 4 Total 12 Medium Risk Electrician Likelihood 4 Total 12 Medium Risk Electric shock. Electrician Likelihood 4 Electricians are trained in the use of hand tools. See RA 22 Hand Tools. Always use a knife so that the blade faces away from you. Always wear PPE as SWP. Never strip a cable on your leg. Always use a support surface when removing insulation. Always wear gloves as per SWP when handling sharp ends. Remove sharp ends with a file ASAP. Electricians are trained in the safe handling of cables. Only fully trained electricians work on distribution boards. Electricians never work on a live distribution board. Distribution boards are isolated at the main switch, locked off, and signs placed prior to DB work taking place. Always use the correct size Pyro glands and locking rings / nuts when making the connection. Total 3 Total 3 RA Number: 46 - Issue Revision: 3 Page 1 of 5

2 TASK HAZARDS PERSONS AFFECTED INITIAL RISK LEVEL CONTROL MEASURES REVISED RISK LEVEL Termination of Pyro to an adaptable box, other connection point on equipment. Making live a Pyro cable after termination. Electric shock. Electrician Likelihood 4 Electric shock. Explosion / fire caused by poor termination. Electrician Likelihood 4 Only fully trained electricians work on Pyro termination. Electricians never work on live equipment. Equipment is isolated at the main switch, locked off, and signs placed prior to work taking place. Only fully trained electricians work on Pyro termination. Circuits are always fully tested prior to making live. See RA / SWP 47 Electrical Testing. RA Number: 46 - Issue Revision: 3 Page 2 of 5

3 Safe Working Practice: 46 Electrical Termination Pyro. 1 PURPOSE: The purpose of this guide is to highlight safe working practices for: Electrical Termination Pyro. THIS MUST NOT BE TREATED AS A SUBSTITUTE FOR TRAINING. 2 PROTECTIVE CLOTHING AND EQUIPMENT Operators must wear Safety Boots/Shoes incorporating steel toe-caps CDI issued work wear Dust masks where appropriate Gloves 3 BEFORE WORK Remember that Pyro cable has no internal colour code; you will establish the polarity of the conductors by testing and identify them with wrap round labelling. Establish whether the cables are to the old colour code (red / black), or the new one (blue / brown). Where an installation contains both colour codes you must place signage as per current regs. Take extra care when working on a mixed colours installation, remember that black is a phase colour on new installs. Ensure that the cables you are to terminate are disconnected from any live source. This can be where cables are already terminated to a fuse board, or are part of any extended circuit. You can test the ends of the cable with a Stienel type tester to ensure they are dead. Visually check the cables for any damage. If damage is found that cannot be repaired the cable must be re-run. If you have not installed the cabling ensure that you understand any labels / markings on the cable so that you are sure of it s source / destination. If you are not sure of this, test the cables first to establish where they run from and to, then re mark / label them prior to final termination. Inspect the installed cable for any damage. Pyro jacket can be easily damaged by sharp edges etc, inspect it carefully; if any damage is found that is not repairable the cable will have to be re run. Where the cable has been left externally ensure that it has not become wet. If it has taken moisture in cut back the length that has got wet, and dispose of it, terminating the dry cores. 4 DURING WORK Note: For the sake of simplicity a back box is referred to here. The method of work is the same for any type of fitting or box. Where you are terminating to a back box, first test the 3.5mm faceplate pins to ensure they run smoothly, the box will need to be changed if there is a problem with these. Where the walls have been plastered around a flush box, cut back any plaster that is overhanging the box lips with a Stanley knife, and remove any detritus from the back box. First measure the length of cable you will need. It will be easier to terminate this cable with the back box you are terminating to unfixed. RA Number: 46 - Issue Revision: 3 Page 3 of 5

4 When you know how much cable you require mark the point where the cable enters the gland on the cable with a permanent maker. Now mark the fixings holes for the back box on the wall, drill them and fit the rawl plugs. Do not screw the box to the wall at this stage. Next fit a gland of the correct size to the back box. Typically this will be a 20mm gland with an inner lock nut. Make sure the lock nut is tight, and does not interfere with the 3.5mm faceplate pin on a back box. You can use a 20mm knock out hole for this, or drill a new hole with a 20mm tank cutter. First cut the end of the shroud with side cutters to just larger than the cable diameter, and pass the shroud over the cable. Next measure how much cable you need to strip, allow for the length you need plus 10%. Mark this point on the cable with a permanent marker pen. Next carefully cut the edge of the Pyro outer jacket down to the point of your mark. Use a Stanley knife-edge on for this, always cut away from yourself, and do not lean on your leg to do it. Strip away all of the outer jacket above this point, it should easily come away from the inner copper jacket once split. Next mark a point 25mm above the edge of the outer PVC jacket on the inner copper jacket. Use a ringing tool to score the copper around the diameter at this point. Next take the gland body and pass it down over the cable. Using a Pyro stripper tool, or bar, slice the end of the copper jacket, lift a piece of copper, and turning the tool remove the inner jacket till it splits off at the point of your score line. It may not be possible to do this all in one piece. At this point the mineral insulation will spill off the cable, make sure you have a sheet placed to collect it, and dispose of it straight away. It is not a hazardous substance. Separate the inner cores. Next take the pot and slide it over the cores till it sits on the top of the inner copper jacket. Turning the pot clockwise will cut a thread onto the jacket and fix it. It is very important to get this tight as this forms part of the earth connection on the cable, however do not over tighten as this can strip the thread. Next take the neoprene sealant, and squeeze a small amount into the pot till it is full. Next take the plastic pot cover, and pass the conductors through it, slide it down and sit it on the pot, neoprene will squeeze out at this point. Taking a pot crimp tool gently squeeze the pot lid cover into the pot. Wipe off any neoprene that has spilled out. The neoprene does not need to dry; you can carry straight on with the termination. Pull the gland body up until the pot sits flush inside it. Now cut lengths of black sleeve. Cut these the length of the conductor less 25mm. Slide the sleeves down over the conductors, till they sit flush with the pot lid. Pass the cable into the back box, tighten it into the box thread, or use a lock ring to fix it. At this point fix the back box to the wall. Bring up the shroud and pull it flush with the back box. Next decide which cores is to be which, mark each core with a coloured tape to denote, phase, neutral, earth, go to the other end of the cable, and using continuity testing determine which are which, and mark the conductors there. Next separate the inner conductors, the jacket edge at this point is very sharp, do not let this cut the insulation of the inner cores. Pass the inner cores through the separator, and pass this down so that it protects the inner core insulation, ensure it sits flush with the end of the outer insulation. Now pass the cable through the gland into the back box. When the end of the outer jacket is flush with the inner lip of the gland tighten the gland up until it grips the cable and will not move. Do not over tighten the gland so that it crushes the cable. RA Number: 46 - Issue Revision: 3 Page 4 of 5

5 At this point fix the back box to the wall. Now take the individual conductors and terminate them to current regulation practices. Establish the correct connections reqired with regard to polarity, and continuity, and working to current regulation practices make the final connections, ensuring that the conductors are crimped down tight, do not move, and cannot pull out of the connector. Push back the faceplate / cover, do not let the faceplate take the strain, hold it in your hand, and push it back firmly into place. Tighten up the faceplate pins, but do not let them take the strain. DO NOT OVERTIGHTEN. Ensure that no cables are crushed behind the faceplate. 5 AFTER WORK Remove all detritus from the area. Carry a scrap bag / box to collect scrap and dispose of it in the designated bin. Remember that cut off edges of outer jacket are sharp, and must be contained in a sharps container. Clean up all mineral powder straight away. Throw away unused neoprene at the end of the day; it is not a hazardous substance. Ensure that all tests are carried out before making live. SEE SWP 50B TESTING. CDI GROUP LTD PLACES GREAT IMPORTANCE ON EVERYONE'S SAFETY: FAILURE TO COMPLY WITH ANY OF THE ABOVE MAY RESULT IN DISCIPLINARY ACTION RA Number: 46 - Issue Revision: 3 Page 5 of 5