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1. A specific customer had several molded case circuit breakers that were spare but where all energized in the substation. The customer had an electrician remove rear cover of the 480 volt switchgear panel while energized to inspect to see which breakers were not being used so he could connect a new load to a breaker. While the electrician was removing the rear cover it slipped from his hands and fell into the switchgear. The resulting arc flash caused hand and face burns to the electrician and burning the inside of the switchgear tripping the main breaker and shutting down part of the plants production. After tending to the electrician's burns, DYMAX was call to clean, test and repair the switchgear on an emergency basis to get the plant production back on line. DYMAX completed the task in less than 12 hours.
2. DYMAX received an emergency call and the Maintenance Supervisor explained that a 2500kva step-up transformer being fed from their peaking generator had caught on fire destroying the transformer and subsequently the 480 volt substation that it fed. Needing to replace all of the damaged equipment and test all associated equipment to ascertain if any peripheral damage was done. The customer hoped to have this equipment available again within one week. DYMAX was able to furnish and install a line-up of remanufactured K-1600 circuit breakers complete with an outdoor enclosure. DYMAX also installed and tested a used 2500kva transformer. Finally, the generator and cables were tested, the relays were tested and calibrated to ensure that no other problems existed. DYMAX was able to meet the customers schedule as the transformer and switchgear were in service five days after the incident.
3. DYMAX received an emergency call from a specific customer around midnight who stated that the circuit breaker feeding their air compressors had tripped and would not reset. As a result, the plant did not have enough air pressure to continue with production. An on call DYMAX technician was on site within two hours of receiving the call. Upon inspection, the technician discovered that the center phase of the circuit breaker feeding the compressors, an ITE 5-HK, had virtually melted down during the fault. DYMAX had the identical model in our circuit breaker inventory. The technician retrieved the circuit breaker, verified the wiring was correct, tested and installed the breaker after cleaning and painting the cubical. DYMAX had the customer back in production within 6 hours of the call.
1. A specific customer had an 80 MVA transformer failure. After performing oil and field electrical testing, it was determined that the reactor windings failed. The replacement options of the transformer were limited. To replace with new cost was about $1,000,000. or used, if a used transformer could be found, at a cost of about $750,000. To ship this 298,000-pound transformer to the manufacturer for in shop repair would have taken 6 months at a cost of about $500,000. DYMAX repaired the transformer on-site for under $200,000. DYMAX removed the 24,000 gallons of transformer fluid and created a 2-foot x 4-foot opening under the reactor to gain access. Using special rigging DYMAX disconnected then lowered the reactor through the opening and replaced and reconnected a new reactor through the same opening. DYMAX fabricated a flange with a recess for an O ring gasket and a cover with a drain plug. After sealing the opening pre-existing oil leaks were repaired. DYMAX pulled vacuum on the transformer and held it for 36 hours. Refilled the transformer with oil after processing and re-energized the transformer. The transformer repair was completed in 10 days on-site.
2. A specific customer had a 40 MVA transformer that needed bent valves and radiators replaced due to shipping damage. DYMAX applied a nitrogen blanket and began pump down of transformer fluid to a storage tank. Following the pump down of the transformer fluid, DYMAX removed the old valves and radiators. Applied plugs to prevent debris from entering the tank. Removed the plugs and replaced the valves, cleaned and dressed the welds. Using a crane lowered the new radiators into position, removed the radiator plugs, set all gaskets and mounted the radiators in place. Applied 3 to 5 pounds of nitrogen for one hour, then applied leak detector to check all welds and seals to ensure no leaks. DYMAX then replaced the nitrogen with dry air. Following all safety procedures for confined spaces, entered the tank of the transformer. DYMAX then inspected the windings and tank. Resealed the access point of the transformer and refilled the transformer with processed oil to manufacturers' specifications. Reapply a nitrogen blanket at 3 to 5 pounds and inspect for leaks. Reduce the nitrogen blanket to one pound of positive pressure. Clean, prime and paint repair points and any scratches on the transformer or radiators. Perform electrical tests, TTR, Power Factor, Insulation Resistance and take oil samples. The transformer repair was completed in 10 days on-site.
3. A specific customer had a 5000 KVA GE transformer. An oil sample taken on March 3rd. Indicated bad DGA. Total combustible gases were 35,196. Individual gases exceeding threshold limits were: hydrogen at 3102 ppm, methane at 11,940 ppm, ethane at 4336 ppm, ethylene at 14,869 ppm, acetylene at 15 ppm. This critical transformer failed 23 days later. The customer had to deal with this situation on an emergency basis.
4. A specific customer had a 2500 KVA RTE/Cooper transformer. An oil sample taken on 3/3/00 indicated bad DGA. Total combustible gases were 1809. Individual gases exceeding threshold limits were: methane at 321 ppm, ethane at 120 ppm, ethylene at 741 ppm, acetylene at 5 ppm. This critical transformer failed on 5/21/00. The customer had to deal with this situation on an emergency basis.
5. A specific customer had a 2500 KVA RTE/Cooper transformer. An oil sample taken on September 2nd. Indicated bad DGA. Total combustible gases were 31,681. Individual gases exceeding threshold limits were: hydrogen at 1205 ppm, methane at 7539 ppm, ethane at 3231 ppm, ethylene at 19,297 ppm, acetylene at 114 ppm. This critical transformer failed 18 days later (after the sample was taken and before the test results were known). The customer had to deal with this situation on an emergency basis. It should be noted that when this same transformer was sampled one year earlier on 9/2/98 the DGA tests were well within normal limits. Total combustible gases were 29. Non-detectable levels were recorded for hydrogen, methane, ethane and acetylene. Ethylene was at 3 ppm
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