---
kind: "section"
citation: "30 C.F.R. § 7.66"
title: "30"
number: "7.66"
heading: "Output energy test."
url: "https://uscodex.org/cfr/30/7.66"
---

# §7.66. Output energy test.

- (a) **Test procedures.** The blasting unit shall be tested by firing into each of the following resistive loads, within a tolerance of ±1%:
  - (1) **The maximum blasting circuit resistance.**
  - (2) **Any resistive load between 3 ohms and the maximum blasting circuit resistance.**
  - (3) **One ohm.**
- (b) **Acceptable performance.**
  - (1) The voltage shall be zero at the firing line terminals 10 milliseconds after operation of the firing switch.
  - (2) The electric current from the blasting unit shall be:
    - (i) **Less than 50 milliamperes except during firing of the blasting unit.**
    - (ii) **Available only through the firing line terminals.**
    - (iii) At least an average of 2 amperes during the first 5 milliseconds following operation of the firing switch.
    - (iv) Not exceed an average of 100 amperes during the first 10 milliseconds following operation of the firing switch.

## Notes

### 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.