Home Applications and Solutions Switchgear Test Systems OLTC Test System
OLTC Test System
The OLTC Test System is designed to test Diverter and Changeover type On Load Tap Changers of ratings up to 400 kV and 300 MVA as per IEC 214. The system carries out tests on the Transition Timing of tap change sequence and ensures the integrity of “Make before Break” performance of the timing sequence.


Tests Conducted

  • Diverter switch timing test (m type timing)
  • V type OLTC timing test
  • Torque test
  • Mechanical test on motor drive
  • Voltage variation test on motor drive
  • Tests on tap position indicator
  • Remote indication test
  • Step – by – step control - single and multiple command tests
  • Limiting device test
  • mV drop test on taps
  • Manual interlock test
  • 2kV insulation test

Controlled Parameter

  • Coil current Make and Break
  • Coil current duration.


  • Accepts wide ranging transition timing resistors
  • Easy-to-use, high level Graphical User Interface and programmable test plans facilitate to create a test setup library
  • Fully automated system requiring minimum operator intervention
  • Connections to the DUT need to be made only once for most tests
  • Test parameters need to be configured only once for each type of OLTC
  • Test sequences can be freely and easily changed
  • Test results are automatically documented and available on demand for printing, storage and analysis
  • Speciality hardware for noise immunization in a typical shop-floor environment

Software Features

  • Windows based Test Manager Software allows sequencing of tests, storing test setups, viewing reports, and analyzing and handling graphical test data using a PC
  • The operator configures the test parameters for the OLTC to be tested and runs the sequence
  • It performs all tests in the programmed sequence, compares each parameter with Pass/Fail limits and declares the OLTC as OK or FAIL
  • Test certificate can be stored and printed as per the manufacturer’s format
  • All test data is stored in a database for analysis

Models Offered

  • The OLTC Test System is offered in two variants, AutoScan DIN 41494 Rack version and AutoScan Work-Table version
  • The AutoScan Rack version, along with accessories like programmable power supplies for driving the motor, torque transducer amplifiers, etc. is expandable to meet future needs of the manufacturer.
  • AutoScan Work-Table version is an ergonomic arrangement of measuring hardware and control PC to help better utilization of space on the shop floor.