Page 62 - RotF - Electrical Specification_Neat

GENERAL ELECTRICAL SPECIFICATION
Version 2014-2

2.9.6 Cable Trays

2.9.6.1 Materials

Cable Trays shall be of the perforated type and shall be formed from plain steel complying
with BS 1449: Part 1B, classification HR4/GP, hot dip galvanised to BS EN ISO1461:1999.
The tray shall be medium duty type having a return flange manufactured from the
following gauge steel.

Width Gauge
102 1.0
152 1.0
229 1.0
305 1.6

2.9.6.2 Installation

Cable tray shall be supported at centres not exceeding 1500mm using galvanised channel
steel brackets spaced from the fabric of the building. Trapeze type brackets shall be
supported using 2 No M6 galvanised steel screwed rods, fixed to the soffit via purpose
made clips.
Manufacturer’s accessories shall be used where possible, where site made accessories are
required these shall be fabricated without welding. The tray work shall be arranged to
minimise the number of cuts necessary. Where cuts are made they shall be painted with
two coats of zinc based paint.

All bolted connections between tray lengths and accessories shall be made round headed
bolts, galvanised to BS 3692 : 2001, to prevent damage to the cables.

Cable tray run on the roof shall be fixed to 50 x 50mm. Tanalised wood blocks so suit the
width of the cable tray, laid on the roof finish at 1500mm centres provided by the
Electrical Contractor.

2.9.7 Cable Basket

2.9.7.1 Materials

Cable basket shall be manufactured and constructed using zinc passivated 5mm steel wire
with a 50mm x 50mm mesh configuration welded at each crossing point.

All Cable Basket fittings (e.g. changes in direction, level and size) shall be constructed on
site, to the manufacturer’s instructions, using side action bolt croppers and fastened using
25mm and 30mm counter clamps with M6 bolts and nuts, all surfaces treated as for the
tray.

McDonalds Restaurants Ltd

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