Risk Assessment & Safe Working Practice

Transcription

1 RA Ref Number: 38 Revision: 3 Project/Job Number Reference Insert Job Number Approval Date: 30/03/2018 RA Description: Installing cable tray and basket Next Review Date: 01/04/2019 Notes: Please refer to Safe Working Practices 38 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 = 17 to 25 = High Risk Issued by: Issue Date: Insert Name Insert Date TASK HAZARDS PERSONS AFFECTED INITIAL RISK LEVEL CONTROL MEASURES REVISED RISK LEVEL Injuries from handling lengths of basket / tray. Engineer / others present Likelihood 4 Engineers do not carry lengths of basket / tray through buildings alone, another person is present to open doors, warn others etc. Basket / tray is stored safely and not left lying around as a trip hazard. A dedicated work area is established for the cutting / setting of basket / tray, and spare lengths are kept here. Only the amount of basket / tray to be used straight away is taken to the work area, others are left in storage until they are required. Injuries from cutting / setting basket tray and cable tray. Engineer Likelihood 4 Only engineers who are trained to do so install / cut basket and tray. Engineers use hand tools that are in good condition, with sharp blades that are not damaged or prone to snapping. Basket / tray is cut on a flat surface. Basket / tray is held firmly whilst it is being cut, either on a workbench, or other suitable surface. Basket / tray is set / bent while it is flat on the work surface, if a full length has to be set, another person holds the trunking during this work to stop it from moving. Where possible pre-made angles and bends are used to remove the need for onsite manufacture. RA Number: 38 - Issue Revision: 3 Page 1 of 5

2 TASK HAZARDS PERSONS AFFECTED INITIAL RISK LEVEL CONTROL MEASURES REVISED RISK LEVEL Injuries from cutting Unistrut supports. Engineer Likelihood 4 Wherever possible Unistrut is cut off site, or supplied cut to length. Only engineers who are trained to do so use the chop saw to cut Unistrut. Engineers are supplied with and use goggles (AC PN 5929), ear protection (AC PN 7745) heavy gloves (AC PN 5927) and arm protection (AC PN 5937). RA Number: 38 - Issue Revision: 3 Page 2 of 5

3 Safe Working Practice: 38 Installing cable tray and basket 1 PURPOSE: The purpose of this guide is to highlight safe working practices for: Installing cable tray and basket. 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 Ear protection where required. 3 BEFORE WORK Cable Tray Cable tray shall be installed to form a backbone supporting cabling along main routes. It can be surface, or below floors / above ceilings, in ceiling voids. There are two main types of cable tray, these are; Steel cable tray shall be manufactured from perforated hot rolled steel in accordance with BS: It shall all be taken from the same range from one manufacturer. Glass Reinforced Plastic (GRP) cable tray shall be manufactured from a polyester resin complying with BS: 476, Part 7, Class2. Where LSOH cables are indicated, the tray shall be manufactured from a resin complying with BS: 476, Part7, Class 1. GRP tray shall be taken from the same range from one manufacturer. Cable tray shall be supplied and installed with all necessary fittings and supports, fully in compliance with the manufacturer s recommendations, and client s requirements. The minimum thickness of steel tray shall be as follows: a. Up to 300 mm in width: 1.5 mm b. Above 300 mm in width: 2.0 mm The minimum flange height for steel tray shall be 12 mm for widths up to 150 mm and 18 mm thereafter. The minimum flange height for GRP tray shall be as follows: a. For widths up to 75 mm: 25 mm b. For widths up to 300 mm: 50 mm c. Above 300 mm: 60 mm Steel cable tray shall be hot dipped galvanised after manufacture in accordance with BS:729. RA Number: 38 - Issue Revision: 3 Page 3 of 5

4 Cable Basket Cable basket is used for backbone containment in the same way as cable tray. Where there are large numbers of cables, or where cables are installed in a raised floor void, cable basket is often used instead of cable tray. Basket lends itself to under floor installation in particular, allowing a greater height of cable bundles to be laid in the same width of route than can be laid using tray. Cable basket shall be manufactured from mild steel wire in accordance with BS: 970, grade 040A04, formed into a 50 mm x 50 mm continuous mesh. The wire shall have a galvanised zinc finish. 4 DURING WORK The tray shall be run in straight lengths and any changes of direction or size shall be made using bends, offsets, reducers, etc. Connections between lengths of cable tray shall be made using coupling pieces. Bends, offsets, coupling pieces, reducers, etc. shall be manufactured and supplied by the manufacturer of the cable tray, complete with earth bonding connections for steel trays. Steel cable tray shall only be cut along a line of plain metal, i.e. not through the perforations. All cut edges shall be filed smooth, and where required by the environment, prepared and treated with rust-inhibiting paint, finished to match the colour of the tray. Cable tray runs shall fit closely to the structure and all necessary bends, etc. shall be provided to enable this to be done. All cable trays shall be supported at a maximum of 150 mm from changes in direction or termination and at a maximum spacing of 2000 mm. Brackets shall support the full width of the tray. Where trays are attached directly to a building surface, stand off supports shall be used to a give a minimum clearance of 40 mm. Brackets shall match the material and finish of the tray. All bolts, nuts, washers, etc. for use with galvanised tray shall be galvanised, and all fittings and fixings for Stainless steel shall be Stainless steel. As far as is practicable, tray runs shall be planned to avoid crossing structural expansion joints, cut where this is impossible purpose-made expansion pieces shall be provided. Cable basket shall be supplied and installed with all necessary fittings and supports, fully in compliance with the manufacturer s recommendations. The basket shall be continuous, run in straight lengths and any changes of direction or size shall be made using bends, offsets, reducers, etc. Connections between lengths of basket shall be made using linkage plates. Bends, offsets, coupling pieces, reducers, etc. shall be manufactured and supplied by the manufacturer of the cable basket, complete with braided earth bonding straps. RA Number: 38 - Issue Revision: 3 Page 4 of 5

5 When cable basket is cut, all cut edges shall be filed smooth, prepared and where required by the environment, treated with rust-inhibiting paint, finished to match the colour of the basket. Cable basket shall fit closely to the structure and all necessary bends, etc. shall be provided to enable this to be done. The minimum thickness of wire shall be as follows: Side Wall Height Longitudinal Transverse 50 mm 4 mm 3 mm > 50 mm 5 mm 4 mm Cable basket shall be supported across the full width, at separations recommended by the manufacturer to achieve a maximum deflection of 0.5% of the span. The basket shall be bolted to its supports. The use of adhesive for this purpose is not permitted. As far as is practicable, basket runs shall be planned to avoid crossing structural expansion joints, but where this is impossible a gap of 10 mm shall be left between two lengths of basket, centred on the joint. 5 AFTER WORK Ensure that all scrap materials are removed from the site. Be aware that off cuts of steel are sharp, so always use appropriate gloves. Always leave the site clean and tidy on completion. 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: 38 - Issue Revision: 3 Page 5 of 5