Lightning & Surge Protection 101 - Part 5

Posted by Mike Agri on 1/26/2012

Today, wireless systems for telephone, alarms, security, and other applications are all the rage. Here is a cautionary tale.

  • At one time, IBM, and later Simplex Time Recorder Company, manufactured electronic, self-correcting clock systems that employed a high power frequency generator wired in parallel across the electrical service. The last minute of every hour, the frequency generator would be turned on for a fixed period of time, and insert one of several available frequencies on the entire AC distribution system in the entire building. The secondary clocks, which plugged into any available single phase, 2-wire 120V outlet, each contained a signal amplifier which turned the frequency into a voltage that would energize a solenoid operated correction mechanism in each clock for system-wide synchronization. It was discovered that If two relatively proximate facilities running on the same utility feed just happened to be set to correct using the same frequencies, it would sometimes result in cross talk between building clock systems which might have one or both facilities with a slightly different Master Clock time setting cause an adjacent facility to also go into correction, with the usual result of each or both systems advancing, every hour.

Lightning & Surge Protection 101 - Part 4

Posted by Mike Agri on 1/13/2012

When people ask me what I do, my usual response is, "I'm the last guy that gets called to fix something after everybody else who could possibly screw it up has been brought in and has failed to find or fix the problem, and usually, only after sins of the installer or subsequent service\installation people have been obscured or exacerbated by subsequent repair or troubleshooting attempts." Over the course of a career, a manufacturer's technical representative gets to see about every kind of "equipment failure" imaginable, and even some that aren't so imaginable.

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