After reading the Forensic Casebook article in the March 2007 issue several times and studying the photographs, I felt compelled to throw in my two cents' worth of rhetoric. My feeling is that the guilt of the incident should come to rest equally on the shoulders of the design engineer, the contractor, and the installing electrician.
First, I noticed the equipment was all NEMA 1 class materials. I feel that with animals and their surroundings constantly emitting vapors from urine, manure, and breathing condensation, moisture and corrosive vapors from cleaning materials would have demanded a NEMA class that is approved for this exposure. The disconnect switch would then be of the stainless steel and gasketed type and the conduits equipped with weatherproof fittings. The installation may have even specified PVC-coated conduit.
Secondly, if this installation was required to meet NEC requirements, then there is one major violation present that is responsible for this calamity. The disconnect switch is being used as a junction box. It's noteworthy that there is no corrosion present on the cable termination in the switch itself. If the cables that were spliced leaked gas that was corrosive, why wasn't the other terminal corroded too? I believe the electrical layout should have been designed as shown in the Figure. This would have eliminated the need for a splice in the disconnect enclosure. I believe the splice was present because the installing electrician most likely pulled all three cables into the disconnect, terminated the neutral on the bar provided, and then cut the feed wires too short. This resulted in the need for a splice. Because the splice was adjacent to the switch's mechanical open/close arm, this could have easily resulted in abrasion to the splice whenever the disconnect was operated. In addition, the electrician didn't identify the conductors with marking tape — or tape the slice with materials that would fit the environment.
Thirdly, I noticed the fuse clip locking clamps in the disconnect. Whenever I see these, it tells me the original connections are no longer providing a good grip for the fuse. This creates heat, which would exacerbate the breakdown of the splice materials. Fuse clips locks are not the solution for poor connections. When you run across this situation, you should install new clips or replace the disconnect.
Lastly, the design engineer should have called for the installation of CO2 detectors and phase failure relays in the control circuits for the fans, with an alarm device to note when either failure occurred.
— Ed Pierce, Huntley, Ill.
As we (at Graybar) read the article, “Your Thoughts on Private Labeling,” in the June 2007 issue, we were perplexed to see that 12.1% of respondents to your survey think that Graybar sells private-label products.
Graybar does sell two non-electrical items that carry the Graybar brand — both of which were long ago developed in conjunction with the suppliers and also have the suppliers' names on them. Perhaps because one of them is a highly visible 5-gallon bucket with a large Graybar logo, some contractors might mistake that for a private-label product.
We feel very strongly that our customers — electrical contractors — value the brand names of the manufacturers. We aren't pursuing any private-label products, and this isn't part of our strategy. Our objective is to offer the highest quality products to our customers and to maintain strong relationships with our suppliers.
The bottom line is that we don't private-label products because we don't believe it's good for our customers or for our suppliers. Anyone with questions about private labeling should talk to their Graybar representative.
— Richard D. Offenbacher, senior vice president - sales and marketing, Graybar, headquartered in St. Louis