Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 1 of 13 PowerPoint presentation Conduit fittings Unit 106: Fabrication techniques for electrical installation

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 2 of 13 Conduit fittings The fittings for metal and PVC conduit are very much the same. There are one or two variations due to the nature of the material. PVC conduit is not threaded, while metal conduit does not require expansion couplers. Metal conduit is available galvanised or with black enamel finish (BE). Conduit sizes: 16mm metal (not widely used) 20mm PVC and metal 25mm PVC and metal 32mm metal

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 3 of 13 Conduit fittings Conduit boxes Conduit boxes are available in a wide range of shapes. All have a standard round box fitted with 4mm tapped holes. Terminal box Through box Tee box

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 4 of 13 Conduit fittings Conduit boxes Four-way box Tangent boxes are available allowing the box to fit close to the wall Also available as: U – Box Y – Box H – Box T – Box Back entry boxes are also available (loop in boxes). See a wholesaler’s catalogue for full details.

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 5 of 13 Conduit fittings Other fittings Male bush – externally threaded (metal), or plain PVC Female bush – internally threaded (metal) Milled-edge locknut Hexagonal locknut

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 6 of 13 Conduit fittings Other fittings Hook plates – used for suspending chain from conduit boxes. Conduit hook – screws into coupler to suspend lighting fittings etc Coupler – internally threaded tube for joining lengths of conduit (plain for PVC) Expansion coupler for PVC

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 7 of 13 Conduit fittings Adaptable boxes – a range of rectangular boxes, with or without knockouts, that allow connection between conduit runs Nipple – a threaded length of conduit allowing connection between conduit runs Flexible conduit – used for connections to vibrating equipment (eg, motors)

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 8 of 13 Conduit fittings Fixing methods Strap saddle – two-hole fixing Spacer bar saddle – single-hole fixing

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 9 of 13 Conduit fittings Fixing methods Distance bar saddle – spaces conduit from wall Hospital saddle – sloping sides prevent build up of dirt Crampet – only used for flush installations

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 10 of 13 Conduit fittings Inspection and non-inspection tees, elbows and sleeves A range of tees, elbows and sleeves are available Non-inspection can only be used within 500mm of an outlet. Inspection fittings provide a limited access for cables

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 11 of 13 Conduit fittings Complete the following table: DescriptionFitting Two-hole saddle Externally threaded bush PVC conduit sizes Length of threaded conduit Box with three outlets Metal coating on conduit Used for hanging chain Device fixing flush conduit

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 12 of 13 Conduit fittings DescriptionFitting Two-hole saddleStrap Externally threaded bushMale PVC conduit sizes20, 25mm Length of threaded conduit Nipple Box with three outletsTee Metal coating on conduitZinc, galvanised Used for hanging chainHook plate Device fixing flush conduit Crampet

Level 1 Diploma in Electrical Installation © 2014 City and Guilds of London Institute. All rights reserved. 13 of 13 Any questions?