More Specifics
To perform the right maintenance, you need certain resources, such as:

• General training. Everyone needs training in areas such as safety, general practices, communication skills, plant systems, and troubleshooting.
• Equipment-specific training. Don't rely solely on equipment manuals if you want an effective maintenance team. Good vendor training will help you meet your downtime prevention goals.
• Test equipment and accessories. Money spent on test equipment is almost always well spent. You can delete the word "almost" from your situation by assessing your measurement needs, and then getting the equipment and training to meet those needs. The right accessories can leverage the investment in many different ways, so don't skimp here.
• Outsourced expertise. For reasons of safety, efficiency, and getting the job done right, outsourcing certain functions is the only logical course. Saving money by doing it yourself isn't cost-effective if the place blows up.

Do you now have two bad drives? Maybe, but chances are neither is bad. The entire system (including the drive) may have been out of whack for a reason that has nothing to do with a drive malfunction. How can you find that reason so you can make the variations go away?

Shorten Repair Times Permanently
Why do professional football players review their previous games on film? After all, they were there -- how does watching again help? It does so by allowing them to examine what they did right and what they did wrong, and perhaps help them do better next time.

That same technique can be applied to repairs. This "review and improve" was standard practice in many maintenance departments (like nuclear generating stations) long before the advent of today's inexpensive video cameras. Back then, maintenance departments used the eyes and mind of a work analyst. This person, who typically had an industrial engineering background, would watch the repairs and then identify where and how things could be done more efficiently. However, that person rarely had the electrical background that would allow the best solutions to emerge.

Football players are the best ones to recommend how to improve their game. Likewise, the people who do the repairs are the best ones to recommend how to improve their game. Consider implementing the video review technique, if you haven't already.

Operation
NEC at the Facility
An installation that complied with the NEC when constructed may later violate it with potentially catastrophic consequences. The installation may not have changed, but something else did. An example of this is protecting conductors and busbars from physical damage in switchboards and panelboards [408.3(1)]. Work performed inside a switchboard or panelboard can easily result in an overlooked loss of mechanical protection. Ensure that it doesn't.

Unsafe Confined Entry Assumption
Never assume that a particular requirement on the permit "isn't really necessary." Discuss your opinion with the entry supervisor. If the permit can be re-issued without that requirement, fine. Otherwise, it's necessary.

Quiz Answers
Answer to Electrical Troubleshooting Quiz
As with any control system, the problem is seldom the controller. It's almost always an input or a control element. Start solving this kind of problem by looking at the inputs. For example, is there a pressure sensor related to line speed? Then, simulate a "typical" pressure, and watch the signal at various points in the system.

Also note that inductive coupling is a common cause of control problems. If a signal wire carrying a millivolt signal runs parallel to 480V wiring, you can get an intermittent "ghost" signal on top of the desired one, which can easily cause line speed variations.