225Electrical firing—precautions during charging

225 Electrical firing—precautions during charging (1) A shot-firer must comply with the following requirements when charges are to be fired electrically: (a) the lead wires of a detonator must be kept short-circuited until the charge is in position and ready for firing; (b) the joints and other parts in a firing circuit must be covered or placed in a way that will prevent electrical contact to earth or with any other thing that could cause a short circuit; (c) the firing cable leading to an explosive charge— (i) must be short-circuited, at the end nearer the firing position, while the detonators are being connected; and (ii) must not be connected to an exploder or circuit tester until the requirements of section 205 (Blasting warnings— general) have been complied with (including the sounding of the warning signals); (d) the short-circuit in the firing cable may be opened only when the explosive charge is ready for testing or firing; (e) before firing the charge, the firing circuit must be tested for continuity and electrical resistance at— (i) the firing position; or

(ii) some other point so distant from the charge that if there is accidental firing there will be no danger to any person; (f) a circuit that is found to be faulty by a test under paragraph (e) must not be used until all faults in the circuit are rectified; (g) immediately after firing, the shot-firer must— (i) render the exploder inoperable; and (ii) disconnect the firing cable; and (iii) replace the short circuit on the firing cable. firing position means the position where the exploder or circuit switch is to be operated to fire the charge.