Lets try the theory again . A new transformer is at 100 % useful life with an estimated DP( degreee of polymerization ) of 800 ( DP=800) and if the insulation is the uninhibited type a 55C rise transformer one of the furans called 2FAL will be 58 ppb( 2FAL=58).When the insulatioon reaches the...
The insulation in a transformer is made up of cellelouse .When this degrades furans are given off and retained in the oil .There are five types of furans and the trending of these furans and their ratio gives an indication of the state of decomposition of the insulation . The furan test is a...
The spring contacts in the tap changer was replaced by a solid copper bar . Any output would be comntrolled by the exciter on the turbine .There was some sludge build up on parts of the contacts but the oil from the main tank keept leakoing into the drained tap changer section ( did not drain...
Good news . The unit has been removed from service and an attempt will be made to by-pass the load tap Changer compartment with all its assoiated problems .We will then degass and run back up . This should take about 7 days . I know that this time is insufficient to properly dry out the...
The LTC has not been used online for the past 10 years .I would assume if it was high energy arching that the acethylene would be increasing rapidly . However the ethylene is increasing at a faster rate which to me indicates a 500 to 700c fault probly a loose ,carbonized or sludged connection (...
How valuable will an Acoustic Emission test be in pinpointing location of fault, Considering background noise , cooling pumps etc ?.
There has been literature on new ratios for LTC the "rose ratios" does anyone have experience using it and how effective is the "Load tap changer signiture...
The unit is free breathing and the elevated gases were found mainly in the LTC the main tank when tested showed only slightly higher levels of Total Combustible gases possibly a carry over from the LTC. When filtered the unit was taken off line and the oil was heated and degassed .The key gases...
Could anyone please advise me ? Currently we are having problems with a Parsons 1963 generation transformer rated at 59MVA with a conservator . The oil is water cooled .The problem seems to be the load Tap changer which for the last ten years has be only changed of-line .Dissolvee gas analysis...
