Metropolitan Industries, of Romeoville, IL, was faced with the challenge of finding a residential market enclosure that would house sump pump power and high voltage components plus an alarm light. Customers who typically purchase these systems were doing so to upgrade because of the high cost of water damage to their homes. They were looking for it to provide them with units that weren't going to fail during infiltration of water.
Russ Farrey, a Metropolitan project designer, had several special needs:
First – The enclosure had to protect the controls: The controls would be exposed to very corrosive environments due to wetness. The unit could be placed in damp basements or possibly outside in the moisture-heavy Everglades. Consequently, when selecting enclosures Farrey took into account studies done on the corrosion of electronics. One of these, included in Chapter 70 of Corrosion Tests and Standards: Application and Interpretation by Robert Baboian, concluded: "Corrosion in the electronics industry has become a significant factor in recent years because of the extremely complex systems that have been developed and the increasing demand on their reliability."
Second – Special conditions had to be considered for copper and silver: Farrey was concerned about the corrosion of some of the sump pump controls because they contain copper and silver. It has been accurately noted in professional evaluations, according to Baboian, that: "Materials used in electronics are susceptible to corrosion in a wide range of environments. For example, sulfidation of silver in H2S occurs in dry as well as humid air. However, moisture in the form of humidity is generally required for atmospheric corrosion to occur. When humidity is increased, a moisture film can form on metallic surface and can yield an increased rate of corrosion. Copper in SO2, for example, corrodes at a steadily increasing rate with increasing humidity."
Third – Cost was a very important factor: Farrey used the cost ratio system for decision-making. This is "a method of supplier performance evaluation that measures the cost of quality, delivery, and service separately for each supplier. Cost ratios are determined by dividing these costs into the total purchases from each supplier. Competitive bids from these suppliers are then adjusted based on their overall cost ratios," according to the National Association of Purchasing Management. The product would be a new offering for Metropolitan, and Farrey started from scratch to find the right enclosure and right supplier. Through his research, he discovered that non-metallic enclosures were the lowest cost solution and would provide protection from wet, corrosive conditions.
After further researching manufacturers of non-metallic enclosures Farrey selected Stahlin Non-Metallic Enclosures, of Belding, MI, as the supplier of choice because of what he perceived to be the best combination of cost, quality, delivery and service.
Specifically, the enclosure specialist met the service criteria of the cost-ratio tool because it was capable of performing factory modifications on the enclosures. This saved Metropolitan from the increased cost of drilling holes themselves – an increase they doubted their customers would be willing to pay. The company needed six precision holes to install the controls. With the holes precut, the products were ready to go out of the box.
Stahlin's ModRight™ Enclosure Modification Program offers customers the opportunity to benefit from Stahlin's diverse in-house capabilities for achieving accurate, cost-effective enclosure modifications and includes cutouts, holes, windows, vents, countersinking, latches and locks, and non-standard sizing.
For more information about Stahlin Non-Metallic Enclosures, contact 616-794-0700 or visit www.stahlin.com.
