Electric systems.

1. (1) Safety switch. A safety switch must be:

   1. (a) Placed at intervals in the permanent firing line when firing from a power circuit.

   2. (b) Made:

      1. (i) So it can only be locked in the "off position"; or
      2. (ii) With a short-circuiting arrangement of the firing lines to the detonator circuit.

2. (2) Lighting gap. A lighting gap must be:

   1. (a) At least five feet ahead (in the firing system) of the main firing switch, between the switch and power source.
   2. (b) Bridged by a flexible jumper cord just before firing the blast.

[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, and 49.17.060. WSR 17-16-132, § 296-52-67230, filed 8/1/17, effective 9/1/17. Statutory Authority: RCW 49.17.010, [49.17].040, and [49.17].050. WSR 02-03-125, § 296-52-67230, filed 1/23/02, effective 3/1/02.]