Page 111 - SMM2 eBOOK

Conduit, trunking and cable trays

R.9 Conduit and fittings

1. Except for final sub-circuits, conduits (measured overall conduit fiKings (e.g. tees, elbows,
bends, cover plates, bushes, locknuts, nipples, stopping-lugs and reducing bushes), short
running lengths and branches) shall be given in metres stating the type and the external
size. Saddles or crampets shall be given in the description stating the pattern and nature
of the background in accordance with clause R.1.6. Bending, cutting, screwing, jointing
and providing all conduit fittings, except those required by clause R.9.2 shall be deemed
to be included with the conduit items. Classitcation shall be as follows:

a. Conduits hxed to sunfaces.
b. Conduits fixed in chases.
c. Conduits embedded in fioor screeds.
d. Conduits embedded in concrete.

2. Special boxes, adaptable boxes, floor-trap boxes, purpose made boxes, rectangular
junction boxes required for drawing in cables, flameproof boxes and expansion joints shall
each be enumerated separately as extra over the conduit in which they occur. Cutting and
jointing conduits to fittings shall be deemed to be included.

3. Flexible conduits and extensible conduits shall be enumerated separately stating the size,
type, overall length and the size and type of termination glands. Cutting, jointing and
providing all conduit httings shall be deemed to be included.

4. Components and special boxes for making connections of conduit into trunking shall be
described and enumerated. Special couplings to equipment shall be described and
enumerated. Forming holes for conduit entry into other items of equipment shall be
deemed to be included.

R.10 Trunking and fittings

1. Trunking (measured over all trunking httings, short running lengths and branches) shall be
given in metres stating the type and size of the trunking, the number and size of any
compartments and the method of jointing. Components for earth-continuity shall be
deemed to be included.

2. Fittings shall be described and enumerated as extra over the trunking in which they occur.
Cutting and jointing trunking to fittings shall be deemed to be included.

3. Connections between trunking and items of equipment or control gear which require the
use of fianges and/or the forming of apertures shall be enumerated stating the size of
openings and the thickness, type and size of any bushing material and/or fianges.

4, Pin-racks for supponting cables in trunking shall be enumerated stating the type and the
size.

R.11 Busbar trunking and fittings

1. Busbar trunking shall be given in accordance with clause R.l O.l stating the type, number
and rated capacity of the busbars and the method of connecting.

2. Tap-off units, feeder units, fire barriers and the like shall each be described and
enumerated stating the type, size and rated capacRy where applicable.

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