BS 6622-2007 pdf free download

BS 6622-2007 pdf free download.Electric cables Armoured cables with thermosetting insulation for rated voltages from 3.8/6.6 kV to 19/33 kV Requirements and test methods.
intended to apply a voltage test to the oversheath after the cable had been laid, to confirm that the oversheath had not been substantially damaged during installation or to detect such damage as might have occurre(l in order to enable repairs to be made.
A d.c. voltage test on the oversheat.h might be necessary in the following situations:
a) when the oversheath is required to perform an insulating function during the operation of the cable. This applies when the method of bonding of the metallic screens of single—core cables is designed to eliminate induced circulating currents, but gbres rise to standing voltages between the metallic screens of the cables of the different phases, e.g. bonding at one position only and cross bon(ling (see C.6);
b) when damage to the oversheath is likely to lead to corrosion of an
essential metallic layer which it protects, due to art environnwnt aggressive to the particular metal.
A.6 Current carrying capacity
The cable that is selected should have a sustained cut-rent rating tinder the conditions of installation not less than the maximum current that it will be required to carry during normal operation. It should also have a short—circuit current rating adequate for the prospective short-circuit current and (he time for which it can persist.
Standardized current rating data for the cables specified in this standard have not been published. Reference should be made to the manufacturer’s rec( immendations.
NOTE I A (imilatkm on the temperature of the cables might be ?we(ted if 11w rubles tiDy to IH’ inSt(llk’(l iii siIiWI?tut.s Uht’n’ people ,niqlil (‘tflHt’ into direct contact with tIrm.
NOTE 2 Owing to the relatively high conductor 1em;wiUuir, then’ is a
risk of buried cables drying out the surrounding soil causing an increase in thtrnud ru’s titily uhith in turn would lead Iv 11w cable teinperatun’ rising to a higher vahw than anticipated. For cable to be laid directly in 11w ground, (I (I c—rating factor should be applied or a lower miLcimuin sustained conductor r,pu rat inti temperature shtndd be assumed, to take into account the joscibh’ ufl’rt of sail diybig out.
NOTE 3 The pemformnance o accessories should be taken into account in deciding the operating temperutu me of the cable.BS 6622-2007 pdf free download.