Types of wiring used in electrical installations: 
<ul><li>A1: wires are lined inside conduit</li>
<li>A2: cable is lined inside conduit</li>
<li>B1: wires are lined on the wall surface inside conduit</li>
<li>B2: cable is lined on the wall surface inside conduit</li>
<li>C: cable or wires on the wall surface without conduit</li>
<li>D: cable is lined inside brick/concrete wall</li>
<li>E: cable or wires near wall</li>
<li>F: wires are lined in open air together</li>
<li>G: wires are lined in open air separately.</li></ul>
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