unclesyd
Materials
- Aug 21, 2002
- 9,819
The company I retired from has just had a massive power failure over almost the entire site caused by a several local rain showers of several inches each in short period of time. The failures occurred in two relatively new switching panels due to water intrusion. The water came in through a roof penetration that apparently that had been sealed completely. This wasn't all that bad but the water traveled down a cable tray and into the switching panels. They were loops on the output DC cables through the roof. The main HV cables come in underground while there are one or two additional partial feeds through the wall.
This greatly affected the area of the plant that requires a 24/7/365 power to supply solid state DC current supply to several hundred DC motors used in production of a synthetic fiber.
Based on previous excursions, the HV supply had been routed to the area from 4 discrete sources and could be switched to retain power to this area at the expense of everything else on site. In this system the generation of DC was at one time, for a long time, supplied by motor generator sets all on separate power supplies and supplying separate production units. But under the newer solid state system the were wired so there could be better interchange of the power thus allowing switching without having to drag large cables around. Evidently two of these unit failed simultaneously and causing the loss of two others that unbalance some HV supplies and breakers flew. I haven’t heard whether the purchased power 110,000 V was lost, again they are two discrete systems.
It was ironic that all, except one, old MG sets had recently been uncoupled from the inside power distribution system and only the one could be brought on line when they restored some HV. It saved a major overhaul on one system saving approximately $150,000 + production loss.
It very prophetic that when an electric engineer whom I have the greatest regard for his abilities made a statement at his retirement party.
The plant manager said: "Terry I reckoned you can retire now that you have all the problems fixed."
Terry's reply was: "That in this business you never find the last fault, but it will find you."
I called him and his comment was that someone threw the wrong switch and we will never know.
I doubt it but I'll try to get some more specific information.
This greatly affected the area of the plant that requires a 24/7/365 power to supply solid state DC current supply to several hundred DC motors used in production of a synthetic fiber.
Based on previous excursions, the HV supply had been routed to the area from 4 discrete sources and could be switched to retain power to this area at the expense of everything else on site. In this system the generation of DC was at one time, for a long time, supplied by motor generator sets all on separate power supplies and supplying separate production units. But under the newer solid state system the were wired so there could be better interchange of the power thus allowing switching without having to drag large cables around. Evidently two of these unit failed simultaneously and causing the loss of two others that unbalance some HV supplies and breakers flew. I haven’t heard whether the purchased power 110,000 V was lost, again they are two discrete systems.
It was ironic that all, except one, old MG sets had recently been uncoupled from the inside power distribution system and only the one could be brought on line when they restored some HV. It saved a major overhaul on one system saving approximately $150,000 + production loss.
It very prophetic that when an electric engineer whom I have the greatest regard for his abilities made a statement at his retirement party.
The plant manager said: "Terry I reckoned you can retire now that you have all the problems fixed."
Terry's reply was: "That in this business you never find the last fault, but it will find you."
I called him and his comment was that someone threw the wrong switch and we will never know.
I doubt it but I'll try to get some more specific information.
