Transformer & OLTC
> What is an On-Load Tap Changer? What is used to control the Tap Changer?
An on-load tap changer (OLTC) is used to change the tapping connection of the transformer winding while the transformer is energized. An automatic voltage regulator, known as TAPCON, is specifically designed and used to control the OLTC which regulates the system desired voltage.

> Why do we need to do OLTC maintenance ?
Maintenance is a key aspect for all high voltage equipment. This ensures that the equipment life cycle is enhanced to the maximum. Safety hazards can also be reduced with appropriate maintenance and checks done on a regular basis. Poor maintenance regime will attain cost savings initially but results in expensive repairs that may even cause production downtime.

> How often do we need to conduct maintenance on OLTC?
Depending on the number of years of service or number of operations, whichever comes first, the OLTC is required to be removed for inspection. During this time the following would be carried out:-
  1. Inspection of contact wear, resistors values, testing of varistors
  2. Checking of mechanical parts, gears, shafts for abnormal wear
  3. Replace with new transformer oil, on-site filtration, on-site oil tests
  4. Testing of protective relay & testing of TAPCON
  5. Replacement of consumable parts (Eg. Head gaskets, relay gaskets, Motor Drive gaskets where applicable)
  6. Updating with new part

> How to maintain transformer insulation oil?
Transformer oil is usually clean and dry. However in a humid environment and overtime, moisture ingress into the transformer is possible through the conservator breather or from points of leakage. To dry and clean the transformer oil, it is necessary to deploy an oil treatment machine at site for filtration, degasification and removal of moisture. The oil treatment process will also help to dry the transformer insulation.
MR On-Load-Tap-Changer
MR Tapcon
MR TAPCON 230 Basic MR TAPCON 240-LV MR TAPCON 240/260
MR Motor Drive Tapmotion & Oil Filter Unit
ED100S Oil Filter Unit OF 100
MR Transformer Accessories : MESSKO
Winding/Oil Temperature gauge
& MDiT Thermometer
Digital Winding Thermometer
EPT 202
Pressure Relief Device
Transformer Control Panel
Nynas New Transformer Oil In Drums
Transformer and Cable Oil Treatment Machinery/Testing equipment.
MR OLTC / Transformer
Maintenance services
Installation and retrofit services Transformer/OLTC oil replacement
and oil treatment
  Lifting of the OLTC from the transformer
  Retrofitted Digital winding temperature
meter installed at site
  Oil filtration machine for oil treatment
  Transformer tank top before maintenance. Due to long time operation, it was thicken with carbon residue from breakdown of insulation oil.
  Operates on the filter machine to purify the oil
  Specialist performing the maintenance exercise
  Retrofit solution of ED100S to replace old motor drive
  Inspect, check contact wear and replacement of consumable parts
  Degasification and removal of moisture
  After maintenance, alignment and measurements, the OLTC is put back in operation.
  Retrofit solution for maintenance free breathers
  Test the transformer oil quality
  Transformer tank top after maintenance.
  New oil after oil treatment
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