Basic Electrical Installation Work

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The installed tray should securely bolted with round-headed bolts where lengths or accessories are attached, that there continuous earth path which may bonded electrical earth. Trunking lid Band II cables Band I cables Band I cables FIGURE 14. is used extensively large industrial and commercial installations for sup- porting and SWA cables which are laid the cable tray and secured with cable ties through the tray holes. When trunking contains rigidly fixed metal barriers along its length, the same trunking may used enclose cables the separate Bands without further precautions, provided that each band separated barrier, as shown Fig.30. used extensively large industrial and commercial installations for support- ing and SWA cables which are laid on the cable tray and secured with cable ties through the tray holes. 14. The tray supplied standard widths from 900mm, and wide range bends, tees and reducers available. The most common fin- ish hot-dipped galvanized but PVC- coated tray also available.31 shows factory made 90° bend The tray can also bent using cable tray bending machine create bends such that shown Fig.30 Segregation cables trunking. Cable tray should adequately supported during installation brackets which are appropriate for the particular installation. The most common finish hot-dipped galvanized but PVC-coated tray also available. Multi-compartment PVC trunking cannot provide band segregations since there metal screen between the Bands. The cable has steel wire armouring giving mechanical Definition Steel wire armoured PVC insulated cables are now extensively used on industrial installations and often laid on cable tray. 14.31. PVC/SWA cable installations Steel wire armoured PVC insulated cables are now extensively used on industrial installations and often laid cable tray. This can only provided in PVC trunking screened cables are drawn into the trunking. Cable tray installations Cable tray sheet-steel channel with multiple holes. .Basic Electrical Installation Work 316 When Band circuits are insulated the same voltage Band circuits, they may drawn into the same compartment. Definition Cable tray sheet-steel channel with multiple holes. Figure 14. This type installation has the advantage flexibility, allowing modifications made speedily as the need arises. The whole tray should provide firm support for the cables and therefore the tray fixings must capable of supporting the weight both the tray and cables. The tray should be bolted the brackets with round-headed bolts and nuts, with the round head inside the tray that cables drawn along the tray are not damaged