M & N M C
9.5 METALLIC AND NON-METALLIC CONDUITS
Steel conduits shall be of galvanised, heavy gauge, Class B, screwed type complying with MS 275-1, IEC 60614-1, IEC 60614-2-1 and IEC 60423 and finished with two coats of approved standard orange paint. All steel conduit fittings shall comply with MS 275-2, IEC 61035-1 and IEC 61035-2-1. The steel conduits shall be fitted with brass bushes at the free ends and expansion devices at appropriate intervals. The ends of each length of steel conduit shall be properly reamed. The termination to the distribution boards, consumer units, switchgears and outlet boxes shall be effected by brass type
smooth-bore bushes. All steel conduits shall be effectively earthed.
For laying underground steel conduit shall be used and buried at a minimum depth of 450 mm below ground level or 100 mm below floor slab or hardstanding. Junction boxes, outlet boxes etc. shall be of galvanised steel or alloy material. The covers shall be galvanised sheet steel with thickness not less than 1.2 mm. Junction boxes downdropping to luminaires shall have diecast cone-shaped metal cover.
For non-metallic conduits and fittings, they shall be of rigid high impact PVC and approved by Jabatan Bomba Dan Penyelamat Malaysia for use in electrical installation. The colour of the conduit for concealed wiring shall be of orange. Unless otherwise for purposes of identification or distinguishing from another services, white coloured conduit shall be used for surface wiring. Rigid high impact PVC conduits shall comply with MS 67, IEC 60614-1, IEC 60614-2-2 and IEC 60423 and fittings shall comply with MS 67, IEC 61035-1 and IEC 61035-2-2.
All fittings for the rigid high impact PVC conduits shall be made and supplied by the same manufacturer for the rigid high impact PVC conduit. The ends of each length of rigid high impact PVC conduit shall be properly reamed. The termination to the distribution boards, consumer units, switchgears and outlet boxes shall be effected by adaptors and lock-rings. Flexible metallic and non-metallic conduits shall comply with IEC 60614-1 and IEC 60614-2-5 and its fittings complying with IEC 61035-1 and IEC 61035-2- 3.
The conduits shall be fixed by means of saddles secured rigidly at intervals not exceeding 750 mm, and within 300 mm of every outlet box, junction box, device box, cabinet or fitting. Steel saddles shall be used for steel conduits. Unless otherwise specified, steel conduits and steel fittings shall be used.