680 likes | 1.55k Views
EE4503 Electrical Systems Design. Raceways. Topics. Introduction to Raceways Conduits Conduit Installations Wireways , Auxiliary Gutters, Cable Trays Fittings. Raceways. Damage e.g. physical, chemical Human Contact Easy Wiring e.g. wiring, maintenance Grounding for Metal Conduit
E N D
EE4503Electrical Systems Design Raceways
Topics • Introduction to Raceways • Conduits • Conduit Installations • Wireways, Auxiliary Gutters, Cable Trays • Fittings
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
Conduits – RMC, IMC, EMT Catalog of Panasoics
Conduits – RMCRigid Metal Conduit • Strongest conduit (except concrete :p) • (Usually) Galvanized • Usage: All weather, all terrain • Standard: ” – 6” (15mm – 150mm) and 3m length
Conduits – IMCIntermediate Metal Conduit • Thinner than RMC • (Usually) Galvanized • Usage: All weather, all terrain • Standard: ” – 4” (15mm – 100mm)and 3m in length
Conduits – EMTElectrical Metallic Tubing • Thinner than IMC & RMC • Not allow to have thread • Usage: Only in building (not under ground, not for high voltage) • Standard: ” – 4” (15mm – 100mm) and 3m in length
Conduits – FMC http://www.delikon.com/brass.htm
Conduits – FMCFlexible Metal Conduit • Metal conduit with the high flexibility • Usage: Vibration or Need Bending • Standard: ” – 3” (15mm – 80mm) • Installation: Need support every 1.5m and 0.3m (in case of termination point / junction box)
Conduits – RNCRigid 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”)
Conduits – RNCDuct Bank http://www.chana.egat.co.th/newweb/gallery/?level=picture&id=28 http://www.iowaconcrete.com/node/707
Conduits – Comparison http://www.mc2-ice.com/services/estref/popular_conversion_files/electrical/conduit_weight.html
Conduits Installation: RMC, IMC Wet Location: accessories needed to be specified as “Raintight” or “Wet locations” http://www.mikeholt.com/instructor2/img/product/pdf/1259687476sample.pdf
Conduits Installation: RMC, IMC Cinder Fill: In corrosive area (e.g. under permanently moist), required at least 2” concrete Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์
Conduits Installation: RMC, IMC Box: Where conduit reaching the box, “bushing” is required to protect the cable’s http://www.electrix.co.uk/view_product_options.php?id=1117 http://ecmweb.com/site-files/ecmweb.com/files/archive/ecmweb.com/images/112ecmCBfig1.jpg
Conduits Installation: RMC, IMC Bend: Number of bends in one run should <= 360o Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์ http://www.tpub.com/ceb/71.htm
Conduits Installation - Supports Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์ http://www.ci.oceanside.ca.us/civica/filebank/blobdload.asp?BlobID=22230
Conduits Installation: RMC, IMC Splices and Taps: only inside the box http://www.diyadvice.com/diy/electrical/fans-heat/whole-house-ventilating-fan/ http://www.familyhandyman.com/DIY-Projects/Lighting/Kitchen-Lighting/how-to-install-under-cabinet-lighting-in-your-kitchen/View-All
Conduits Installation - # of Cables • Need space inside conduit: • Heat Ventilation • Cable’s insulator will not be damaged. http://www.simpullsolutions.com/documents/SIMpullTHHNInstallationandApplicationGuide8-15-07.pdf
Conduits Installation - # of Cablestable http://www.telepart.net/ตารางการติดตั้งสายไฟในท่อWire-Conduit-Table.html
Conduits Installation - # of Cablescalculation Calculate directly from the cable’s outer diameter () and conduit’s inner diameter () and is the number of cables.
Wireways http://www.indochinaengineering.co.th/product.php?id_product=30
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
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.
Auxiliary Gutters • Similar to wireways • Collect the cable before distribute. http://www.contractortalk.com/f32/some-recent-work-34277/
Cable Trays http://www.indochinaengineering.co.th/product.php?id_product=32
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
Cable Trays – Ladder Type For heavy-duty power distribution http://www.shreemahalaxmisteel.com/cable-trays.html http://www.ezziengineering.com/images/Cable_Tray_Catalogue.pdf
Cable Trays – Perforated Type For power cables, small cables and control cables http://www.shreemahalaxmisteel.com/cable-trays.html http://www.ezziengineering.com/images/Cable_Tray_Catalogue.pdf
Cable Trays – Solid Bottom Type For small cables. http://www.ezziengineering.com/images/Cable_Tray_Catalogue.pdf
Cable Trays – Comparison http://www.cooperindustries.com/content/dam/public/bline/Resources/Library/catalogs/cable_tray_systems/all_products/CTManual.pdf
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
Fittings - Boxes • 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.
Fittings - Boxes http://www.topaz-usa.com/catalogs/electrical_fittings_catalog.pdf
Fittings – Pull Boxes http://ecmweb.com/code-basics/sizing-junction-boxes
Fittings – Pull Boxesstraight pulls The horizontal dimension (A) is 8 times of the largest raceway size. http://ecmweb.com/code-basics/sizing-junction-boxes
Fittings – Pull Boxesangle pulls The distance between raceways (C) is 6 times of the diameters of the raceways. http://ecmweb.com/code-basics/sizing-junction-boxes
Fittings – Other AccessoriesConnectors • Steel Coupling • Compression • Set Screw • Rain Tight http://www.topaz-usa.com/catalogs/electrical_fittings_catalog.pdf http://numthaveerung.co.th/pdf/Steel%20Conduit-Accessories%20Fitting.pdf
Fittings – Other AccessoriesBushing • Metal • Non-metal • Grouding http://www.topaz-usa.com/catalogs/electrical_fittings_catalog.pdf
Fittings – Other AccessoriesElbow & Strap • Elbow • Strap http://www.topaz-usa.com/catalogs/electrical_fittings_catalog.pdf
Reference • Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์