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


Bottleneck Motor Repairs, Part 1
In the previous issue, we looked at the concept of production bottlenecks — those restriction points in the production "piping system" that limit overall flow of product out the door.

For purposes of both maintenance and repair, you need to identify your bottleneck motors. For example, if six production lines converge onto a single palletizing line, then that palletizing line is a bottleneck and so is its drive motor. When the palletizing motor is down, the output of all six lines goes nowhere.

If the palletizing motor and the Line 2 drive motor are down at the same time, which one sits while the other one gets repaired? Your choice is obvious.

Not only can the bottleneck concept help you decide which fire to put out first, it also can help you prevent fires in the first place. In our next issue, we’ll explore this further.


Operation
NEC in the Facility
If your site has a Class I location (flammable gases, vapors, or liquids), you probably know that any electrical parts operating at more than 30V can't be exposed. But did you know this threshold drops to 15V under wet conditions [501.25]?

If you have exposed parts in a Class I location, make sure you apply the appropriate protection technique from 500.7(E), (F), or (G) to them.

Be careful when grounding in Class I locations. Grounding where you should bond violates 501.30 and creates a dangerous difference of potential. To avoid this, know the definitions of grounding and bonding [Art. 100].


Safety
The Sleep Institute has conducted extensive studies on the effects of sleep deprivation. One of those effects can make you unsafe. The studies show that if you’re 20% sleep-deprived, you’re as mentally impaired as if you were drunk.

In addition to putting you at risk all on its own, sleep deprivation compounds the effects of drugs that diminish alertness or alter judgment — for example, alcohol or antihistamines. It can make the ordinarily safe use of a given substance or remedy extraordinarily dangerous.

The real kicker is another fact that the Sleep Institute discovered: Most sleep-deprived people are unaware of how severe their problem is.

What should you do? Online, you can find books and courses to help you determine if you have a sleep problem and help you solve it.


Quiz Answer
Answer to Electrical Troubleshooting Quiz
A drop in light output is hard to isolate in time, because it tends to creep up on us. As light output diminishes a little each day, we adjust to the new normal. That makes troubleshooting more difficult, but not impossible.

Light output diminishes as lamps near end of life (the output curve varies by lamp type). So, maybe it’s just be time for relamping. However, there are probably other factors to correct. Things to check include:

• Dust and grime accumulation. Are the lamps, lenses, and shades clean?
• Overloaded neutrals. A plastics plant in Kentucky solved a dim lighting problem in one building by rewiring the lighting system. Most of the neutral wires had overheated to the point of discoloration. This rewiring more than doubled some footcandle readings.
• Transient protection deficiencies. Is your surge protection (Art. 285) plan tiered so that it protects lighting ballasts from events generated from inside your facility? If not, you probably have damaged ballasts. Replace a few ballasts to see the effect. Correct the protection deficiencies.
• Bonding deficiencies. Walk down your lighting system for violations of Art. 250, Part V. You should not have connections to ground (as defined in Art. 100) anywhere in this system.