Section 199(8) in The Coal Mines Regulations, 2011
(8)Where more than one shot are to be fire at the same time,-(a)care shall be taken that all connections are properly made;(b)all shots if fired belowground shall be connected in series;(c)the circuit shall be tested either for electrical resistance or for continuity before connecting it to the firing apparatus and such a test shall be made with an apparatus specifically designed for the purpose and only after all persons in the vicinity have taken proper shelter as provided under regulation 200;(d)the cable to the shotfiring apparatus shall be connected last; and(e)detonators of the same electrical resistance shall only be used.
