PVC insulated cables

BS6231 Specification for PVC insulated cables for switchgear and control gear wiring. 

Szabo, I. Fire protection of PVC-insulated cables, (in Hungarian). Muanyag ds Gumiy 13, 125 (1976)... 

Six 2.5 mm PVC insulated cables are to be run in a conduit containing two bends between boxes 10m apart. Determine the minimum size of conduit to contain these cables. 

Steel wire armoured PVC insulated cables are now extensively used on industrial installations and often laid on cable tray. This type of installation has the advantage of flexibility, allowing modifications to be made speedily as the need arises. The cable has a steel wire armouring giving mechanical protection... 

Steel wire armoured PVC insulated cables are now extensively used on industrial installations and often laid on cable tray. 

PVC insulated cables are usually drawn into an erected conduit installation or laid into an erected trunking installation. Table 5D of the On Site Guide only gives factors for conduits up to 32 mm in diameter, which would indicate that conduits larger than this are not in frequent or common use. Where a cable enclosure greater than 32 mm is required because of the number or size of the conductors, it is generally more economical and convenient to use trunking. 

In a normally closed circuit, the alarm call points are coimected in series to normally closed contacts as shown in Fig. 14.48. When the alarm is initiated, or if a break occurs in the wiring, the alarm is activated. The soimders and master control unit must be wired in MI or FP200 cable, but the call points may be wired in PVC insulated cable since this circuit will always fail safe . 

The three foregoing types of wiring are all vulnerable to mechanical damage which may cause short circuits or leakage and lead to ignitions. PVC-insulated cables in metal conduit or trunking are better protected and are much less of a fire risk because in the event of a fault the metal enclosure is a fire barrier. 

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