Recent content by Kent Irwin

  1. K

    Energized Electrical Work Permits

    We do monthly permits for repetitive tasks only. Our Electrical Safe Work Practices policy spells out clearly what qualifies for a monthly permit and what does not. In the management culture where I work I was lucky to win that much.
  2. K

    Energized Electrical Work Permits

    Zarheer, I believe you'll find that Hugh Hoagland in his course teaches that permits can be annual for repetitive tasks. For what we do an individual permit for testing every single manufactured or serviced system is overly burdensome and management would never accept it.
  3. K

    Energized Electrical Work Permits

    I'm the electrical safety guy for a manufacturer where manufactured system testing involves exposed energized parts. All of our locations all do monthly blanket permits for typical system start up testing or servicing. We could do an annual permit but I believe a hazard risk analysis and job...
  4. K

    Using Ground Set on 480V

    If you know the available bolted fault current, ask the new engineer what size grounding cable set you should buy that will carry that amount of current until the upstream over-current device opens the circuit.
  5. K

    Using Rubber Glove Protectors as Work Gloves

    I have never seen anything that forbids you to use the leather protector for other purposes. I wouldn't consider it a good practice though. The leather glove will just get beaten up and worn out sooner. But again, I've seen nothing that prohibits it.
  6. K

    what is a cal/cm2

    I can't really tell you how it came to be but here's an explanation - A calorie is the energy required to raise one gram of water one degree Celsius at one atmosphere. The onset of second-degree burns may occur from 1.2 calories/cm2. One calorie/cm2 can be equal to holding your finger over the...
  7. K

    Minimum Distance from a Panel

    For shock hazard the distance is dependent on voltage level. At 480/277V the limited approach boundary would be 42", the restricted approach boundary 12". For arc flash hazard it is dependent on the results of an arc flash analysis.