The answer to this question appears at the end of this newsletter.


Repair Scripts: The Checklist
When machinery goes down, what is the priority? Getting that machinery back up, of course. Unfortunately, the pressure to end downtime often leads to incomplete troubleshooting and insufficient repair.

For example, a motor stops running. Using your advanced knowledge of motors, you determine that the large cloud of smoke curling up from the windings indicates there might be a problem with the motor. You replace the motor, and production is once more humming along. You wanted to figure out what toasted that motor, but there just wasn't time to do that. Or was there?

Using a standardized checklist developed for each specific piece of production equipment, you can usually identify the root cause of a failure -- and quickly. By doing your thinking, researching, and planning when the equipment is up, you don't have to do those things during the pressure-cooker of downtime.

If you haven't created checklists before, you probably should ease into doing so. Start with the equipment that can least tolerate downtime. Read the manufacturer's literature, walk down the system drawings, look through the PLC programming, and so forth. Make a short list of potential failures and what to check to see of those exist. Stop as soon as you have a decent-sized list, so this task doesn't overwhelm you. As new problems are identified, just update your checklist. It isn't necessary to determine every possible cause when you first develop the list.

A good checklist will be divided up into short user-friendly sections, such as these:

• Quick checks
• Supply measurements
• Load inspections
• Top potential failure causes
• Programming checks

As you build each checklist, keep in mind you are trying to do the most useful checks in a limited window of downtime. You may not catch the root cause with your checklist, and the downtime will occur again for the same reason as last time. But at least it won't be for something obvious like voltage imbalance on the supply to a motor.

Operation
NEC at the Facility
How can any facility exist without flexible cords? We see them everywhere. We count on them to safely provide power in a wide variety of conditions and for a wide variety of purposes. The phrase "flexible cords" includes those portable power cords you depend on, but goes beyond them as well. Flexible cords fall under Article 400. When is the last time you reviewed those requirements against your cord inventory and usage?


Unsafe Assumptions
In our previous edition, we pointed out that most industrial accidents occur because of what people do. That is, unsafe acts cause accidents and injuries. But where do unsafe acts come from? One source is incorrect assumptions, such as these:

• "Warming up in the switchgear room is better than freezing out here." Nobody says getting frostbite is good. But entering a switchgear room when you don't have to, especially if you aren't wearing the appropriate arc blast protection, is foolish.
• "If there's a ground fault, the overcurrent device will protect me." During a low-grade fault, an OCPD can hold long past the time you become charcoal. It won't protect you.
• "If I'm walking to my work area, safety glasses aren't necessary because I'm not actually working yet." The purpose of wearing safety glasses has nothing to do whether you are working. It has to do with what dangers may be present. Studies have shown that standard safety glasses outperform the best excuses, every time.

Show & Events

Visit the EC&M E-Tradeshow and Learn About Claim Litigation
Don't miss the live conference Claim Litigation: Bolstering Your Case presented by John DeDad, senior director, editorial and EC&M development, scheduled for March 15th. Learn how to retrieve costs resulting from undesirable and/or unplanned working conditions that are beyond your control. Find out how to document various claim categories such as acceleration and resulting decreased productivity, additional engineering costs for change-order work, additional financing expenses, and joint occupancy with other work forces. Visit http://ecmweb.com/etradeshow for information on accessing the EC&M e-Tradeshow, a virtual online exhibition and live conference center.


Quiz Answers
Answer to Electrical Troubleshooting Quiz Every motor replacement involves downtime. The trick to getting "troubleshooting downtime" is to realize that troubleshooting isn't necessarily sequential to replacement. These tasks can, and often should, be done simultaneously.

Develop a troubleshooting script. If you can base this on post-mortems of the other drive motors that failed, that's ideal. Have one team troubleshoot while another team does the remove/replace drill. If production management balks at the cost of two teams instead of one, then that motor probably isn't so critical after all.