CFR /  Title 30  /  Part 57  /  Sec. 57.6401 Shunting.

Except during testing--

(a) Electric detonators shall be kept shunted until connected to the blasting line or wired into a blasting round;

(b) Wired rounds shall be kept shunted until connected to the blasting line; and

(c) Blasting lines shall be kept shunted until immediately before blasting.