Assumption University Thailand EE4503 Electrical Systems Design Raceways 1

Assumption University Thailand Topics Introduction to Raceways Conduits Conduit Installations Wireways, Auxiliary Gutters, Cable Trays Fittings 2

Assumption University Thailand Raceways Damage e.g. physical, chemical Human Contact Easy Wiring e.g. wiring, maintenance Grounding for Metal Conduit Limit the scope of damage e.g. fire, short circuit 3

Assumption University Thailand Conduits – RMC, IMC, EMT Catalog of Panasoics 4

Assumption University Thailand Conduits – RMC Rigid Metal Conduit 5

Assumption University Thailand Conduits – IMC Intermediate Metal Conduit 6

Assumption University Thailand Conduits – EMT Electrical Metallic Tubing 7

Assumption University Thailand Conduits – FMC 8

Assumption University Thailand Conduits – FMC Flexible Metal Conduit 9

Assumption University Thailand Conduits – RNC Rigid Nonmetallic Conduit Built from nonmetallic material: e.g. PVC Disadvantage: Not as strong as metal and limit temperature usage Advantage: Sustain to erosion, humidity, impact Usage: Exposed, Conceal, Wet & Himid or underground (usually using “duct bank”) 10

Assumption University Thailand Conduits – RNC Duct Bank

Assumption University Thailand Conduits – Comparison 12

Assumption University Thailand Conduits Installation: RMC, IMC 13 Wet Location: accessories needed to be specified as “Raintight” or “Wet locations”

Assumption University Thailand Conduits Installation: RMC, IMC Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์ 14 Cinder Fill: In corrosive area (e.g. under permanently moist), required at least 2” concrete

Assumption University Thailand Conduits Installation: RMC, IMC Box: Where conduit reaching the box, “bushing” is required to protect the cable’s

Assumption University Thailand Conduits Installation: RMC, IMC Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์ 16 Bend: Number of bends in one run should <= 360 o

Assumption University Thailand Conduits Installation - Supports Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์ 17

Assumption University Thailand Conduits Installation: RMC, IMC Splices and Taps: only inside the box

Assumption University Thailand Conduits Installation - # of Cables Need space inside conduit: –Heat Ventilation –Cable’s insulator will not be damaged. 19

Assumption University Thailand Conduits Installation - # of Cables table 20 ตารางการติดตั้งสายไฟในท่อ Wire-Conduit-Table.html

Assumption University Thailand Conduits Installation - # of Cables calculation 21

Assumption University Thailand Wireways 22

Assumption University Thailand Wireways Raceways are folded from sheet metal. General usage in open area. If outside building, specify “Raintight” Not use when risk of severe physical damage. Height: 50, 75, 100, 150, 200 mm Width: 50, 75, 100, 150, 200, 250, 300 mm 23

Assumption University Thailand Wireways Use current rated for the metal conduit. Use reduction factor, if > 30 cables. Need supports for every 1.5m. Cannot use through the wall or floor. Cannot use as grounding cable. Use no more than 20% fill. 24

Assumption University Thailand Auxiliary Gutters Similar to wireways Collect the cable before distribute. 25

Assumption University Thailand Cable Trays 26

Assumption University Thailand Cable Trays Cable Tray is not Raceways, but is commonly used in industry to support cable. Cheap and easy to use. Only for specific cable types, e.g. multi- core cables 27

Assumption University Thailand Cable Trays – Ladder Type For heavy-duty power distribution

Assumption University Thailand Cable Trays – Perforated Type For power cables, small cables and control cables

Assumption University Thailand Cable Trays – Solid Bottom Type For small cables. 30

Assumption University Thailand Cable Trays – Comparison 31

Assumption University Thailand Fittings Accessories to be used with race way. Purpose –To firmly hang the raceway –To smoothly change the direction of raceway –To easily pull the cable into the raceway –To properly splice the cables 32

Assumption University Thailand Fittings - Boxes 33 Termination point (switch, receptacle) or Stop point (splice, tap) for the wiring system. Metal or non-metal. Sizing is based on the required space. Have no hole for the object larger than 7.5 mm in diameter to pass thru.

Assumption University Thailand Fittings - Boxes 34

Assumption University Thailand Fittings – Pull Boxes 35

Assumption University Thailand Fittings – Pull Boxes straight pulls 36 The horizontal dimension (A) is 8 times of the largest raceway size.

Assumption University Thailand Fittings – Pull Boxes angle pulls 37 The distance between raceways (C) is 6 times of the diameters of the raceways.

Assumption University Thailand Fittings – Other Accessories Connectors Steel Coupling Compression Set Screw Rain Tight

Assumption University Thailand Fittings – Other Accessories Bushing 39 Metal Non-metal Grouding

Assumption University Thailand Fittings – Other Accessories Elbow & Strap 40 Elbow Strap

Assumption University Thailand Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์ Reference 41