§7.69. Approval marking.
30 C.F.R. § 7.69
Each approved blasting unit shall be identified as permissible by a legible and permanent marking securely attached, stamped, or molded to the outside of the unit. This marking shall include the following:
The assigned MSHA approval number.
The maximum blasting circuit resistance.
A warning that the unit's components must not be disassembled or removed.
The replacement battery types if the unit has replaceable batteries.
A warning placed next to the charging connector that the battery only be charged in a fresh air location if rechargeable batteries are used.
A warning that the unit is compatible only with detonators that will—
Fire when an average of 1.5 amperes is applied for 5 milliseconds;
Not misfire when up to an average 100 amperes is applied for 10 milliseconds; and
Not fire when a current of 250 milliamperes or less is applied.
Notes, amendments, and revision history
Source
Source: 54 FR 48210, Nov. 21, 1989, unless otherwise noted.
Authority
Authority: 30 U.S.C. 957.
Source
Source: 53 FR 23500, June 22, 1988, unless otherwise noted.