Archive for January, 2013

50 Mva and 50 Kva Oil Filled Power Transformer, Technical Conversations

Posted on January 31st, 2013 in Power Transformers | No Comments »

MIDWEST’s Switchgear Technical Center is always busy, but sometimes it can be extremely busy, loud and a little wild with the cross talk between the technical work stations. To an outsider, the noise, excitement, fast technical jargon and obvious intensity might make them wonder how anyone could function in such an environment. It would certainly drive the meek crazy. But the Engineers and Techies love the action. It can vary from the urgent to the absurd. Here’s an example of two separate but simultaneous energized conversations between MIDWEST’s Switchgear Technical Center and two customers. Each of the two conversations sounded almost exactly the same. Both conversations were about reconditioned or new oil filled electrical power transformers. 50 Kva oil filled 480 to 240 volt transformers and a 50 Mva oil filled 13,200 volts to 138 Kv GST transformer. One small oil filled transformer and one massive oil filled power transformer. Both conversations had a sense of urgency, one days and the other months. Both had a steady stream of technical details, a time table, preparation, freight, trucking, tests, some frustrations, as MIDWEST ground through each detail, double checking and confirming them one by one. A listener might think they were selling the same thing. They sound alike. 50 Mva and 50 Kva. Actually they were, oil filled electrical power transformers. But one was electrically a thousand times larger than the other. 50,000 Kva and 50 Kva. Just another day in the technical world.

No to eBay Circuit Breakers

Posted on January 23rd, 2013 in Circuit Breakers | No Comments »

It has happened again. A contractor 5 states away called with an urgent need for a Square D PEF361000 circuit breaker. They had a customer in trouble and needed a replacement breaker right away. They found one on eBay and were squabbling with our Switchgear Group because they wanted us to honor the eBay price, half of ours. We tried to explain eBay was a buyer beware market, whereas MIDWEST’s PEF361000 price was for a fully tested circuit breaker. He understood, but like others before him, he emotionally just could not get over the low cost of the eBay breaker. He was persistent in demanding we sell him the breaker at the lower price. Then he said he didn’t care about the testing, just send it. He didn’t need the testing and did not want to pay for it. He was very unhappy when our Engineer explained we would not do that. When bad electrical things are happening, it is not unusual for some folks to cling to their emotional decisions, even in the face of clear reason to the contrary.  Our job is to take care of the customer safely. In cases like this, we explain the circuit breaker must be tested to make sure that it not only operates properly, but also is safe. That it doesn’t blow up in their face or allow their customer’s equipment to be damaged because it will not interrupt a fault. MIDWEST would test the circuit breaker for insulation resistance, contact resistance, high current testing, high current voltage drop tests, reset tests, proper mechanical function, and internal inspection and maintenance. And we clean it up so it looks good too. GE General Electric, Westinghouse, Cutler Hammer, Square D, Siemens, all the manufacturers. 1000 amp, 1500 amp, or 2000 amp circuit breakers. It doesn’t make any difference. They need to be properly tested and maintained before they are sold into the secondary market. Buyer beware is not an acceptable safety policy.