Code of Practice for the Electricity (Wiring) Regulations - 2009 Edition
Code of Practice for the Electricity (Wiring) Regulations - 2009 Edition
Code of Practice for the Electricity (Wiring) Regulations - 2009 Edition
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(d ) Electrical equipment and wiring <strong>of</strong> electrical installations in mines<br />
should comply with <strong>the</strong> Mining Ordinance and Mines (Safety)<br />
<strong>Regulations</strong> (Cap. 285), and should be constructed and protected to<br />
relevant recognised standards.<br />
(2) Electrical equipment selection<br />
(a) Type <strong>of</strong> protection <strong>of</strong> electrical equipment <strong>for</strong> achievement <strong>of</strong> safety<br />
should be in accordance to zone <strong>of</strong> risk listed in Table 15(4).<br />
(b) The maximum surface temperature <strong>of</strong> <strong>the</strong> T class <strong>of</strong> an electrical<br />
equipment should not exceed <strong>the</strong> ignition temperature <strong>of</strong> <strong>the</strong> gases<br />
or vapours involved. Relationship between T class and maximum<br />
surface temperature is shown in Table 15(5).<br />
(c) Electrical equipment with <strong>the</strong> appropriate apparatus group should be<br />
used.<br />
Group I: Electrical apparatus <strong>for</strong> mines susceptible to firedamp.<br />
Group II: Electrical apparatus <strong>for</strong> places with a potentially explosive<br />
atmosphere, o<strong>the</strong>r than mines susceptible to firedamp.<br />
(3) <strong>Wiring</strong> systems<br />
The type <strong>of</strong> wiring that may be used <strong>for</strong> installation in hazardous areas,<br />
and <strong>the</strong> requirements <strong>for</strong> permitted types <strong>of</strong> cable and <strong>the</strong>ir accessories<br />
dealing with individual types <strong>of</strong> protection should comply with <strong>the</strong><br />
recommendations laid down in IEC 60079 or equivalent. All cables,<br />
conduit and <strong>the</strong>ir accessories should be manufactured to appropriate<br />
recognised standards.<br />
15E Impact (AG)<br />
(a) A wiring system should be selected and erected so as to minimise<br />
mechanical damage.<br />
(b) In a fixed installation where an impact <strong>of</strong> medium severity (AG2) or high<br />
severity (AG3) can occur, protection should be af<strong>for</strong>ded by:<br />
(i) <strong>the</strong> mechanical characteristics <strong>of</strong> <strong>the</strong> wiring system, or<br />
(ii) <strong>the</strong> location selected, or<br />
(iii) <strong>the</strong> provision <strong>of</strong> additional local or general mechanical protection,<br />
or by any combination <strong>of</strong> <strong>the</strong> above.<br />
(c) Except where installed in a conduit or duct which provides equivalent<br />
mechanical protection, a cable buried in ground should be <strong>of</strong> a<br />
construction incorporating an armour or metal sheath or both, or be <strong>of</strong><br />
insulated concentric construction. Such cable should be marked by cable<br />
covers or a suitable marking tape or by suitable identification <strong>of</strong> <strong>the</strong><br />
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