Instrument Division (Abi Instrument)

Abi Instrument was started in the year 2006 as an Instrumentation & Testing Division of our Company. We have been a service provider for Power Sectors in both Generation and Distribution side and mainly in the Power Transformer field since 1992. As we are in the field of Servicing of meters meant for Transformer protection, we started thinking of developing a Digital Temperature Meter as a substitute for conventional analog type Oil and Winding Temperature (WTI & OTI) Meters. As a result of our vast experience and thorough R & D, we designed and Developed a Digital Winding & Oil Temperature Indicator (WTI & OTI) with high Caliber of Accuracy and Reliability with all the Advanced Features.

We also manufacture analog type of Oil and Winding Temperature Indicators with various models. ( WTI & OTI )

  • Some of the products developed by us are given below:
  • Online Winding Temperature Monitoring System (OLWTM – 10)
  • Winding Temperature Indicator / Controller (MODEL: WTI-10)
  • Analog Type WTI & OTI , Mercury Switch Type (Model-2001,2002,2003,2030)
  • Analog Type WTI & OTI,Micro Switch Type(Model 2006,2031) Note Over)

    OLWTM-10 is a compact system, specifically designed for ONLINE MONITORING AND CONTROLLING OF OIL & WINDING TEMPERATURE OF POWER TRANSFORMERS. It comprises user friendly interfaces of 4x4 matrix keys, 20x4 Alpha Numeric LCD display, seven segments LED Display, RS 232 Serial port communication output for Modem / PC Internal memory unit and RS485 two wire communication output for repeater. It records winding temperature or oil temperature in every one hour, daily maximum and minimum temperature and relay status. By request it will send SMS to all user-defined mobile phones about the instant oil temperature, winding temperature and load current along with relay status. We can retrieve stored data to our laptop or scroll and view in the instrument itself, also it can be directly connected to PC for instantaneous data logging. It comes with repeater for control room display. It is suitable for any make, capacity, voltage class, transformers.



  • Displays Oil, Winding Temperature & Load current
  • Seven segment LED display for better vision, in addition to LCD Display

  • Maximum of 720 periodic records in the time interval from 1minute to 180 minute set by the user
  • Day Maximum and Minimum Temperature records for up to 30 days
  • Month Max-Min Temperature records in memory up to 12 months
  • Year Max-Min Temperature records up to 3 years
  • Relay activation records with Date ,Time & Temperature
  • Provision to clear all the previous records and starts anew
  • Reset the max. temperature records alone

  • Password protection for settings
  • There are four set points (set temperatures), for four relays
  • Delay & Differential settings for relays
  • Provision to set the Temperature gradient (dT ºC) of winding temperature
  • Options for setting Load current up to 9999 Amps, and CT secondary current from 1to5 Amps
  • User can set their own time and date
  • User can load the default settings
  • Provision for Buzzer time setting
  • User can configure each relay either for OTI or WTI

  • RS485 communication output for repeater with relay activation status
  • RS232 serial communication output for MODEM or computer or memory unit
  • Parameters like Oil temp, winding temp, load current and relay status can be accessed remotely through mobile phone / Lap top / PC
  • 4sets of 5Amps relay contact outputs
  • wide auxiliary input supply in the range of 90-260V AC/DC

  • RTD PT-100: The most linear response to the Temperature raise

    It is a compact device, specifically designed for measuring Winding Temperature of power transformers in line to measure & display Oil Temperature and Load Current and records maximum temperature. It comprises user friendly interfaces of 4 Input keys, 16x2 Alpha Numeric LCD display, and RS485 Serial port communication output for Repeater.


    Generally in Power Transformers, windings with higher Voltage and insulation criteria, direct access to the windings for installation of a temperature sensor is NOT possible. Therefore to measure the winding temperature, we have to measure the oil temperature and add temp proportionate to load current, since winding temperature is proportionate to load current. Under load conditions the proportionate current of CT secondary is measured and correlated with the temperature gradient given by the transformer manufacturer depending upon the design features. This derived temperature is added to the top oil temperature of the transformer measured using a RTD sensor. Thus the exact winding temperature is obtained.


    This model WTI-10 is designed for protection of oil cooled power transformers. WTI-10 (96x96MM) is a digital temperature indicator/controller; this controller can be installed in control room as well as in marshalling box of the transformer. It has two inputs, one for RTD sensor and one for CT input and two outputs for relay contacts such as Alarm & Trip signal. Optional one RS 485 serial communication output for repeater. This instrument is suitable for any make, capacity, or voltage class of transformers


    For Remote indication of oil, winding temperature and load current, RS485 serial communication outputs are available with the WTI-10.These signal outputs are to be connected to repeater (model RWTI-20) for remote indication of these parameters. RWTI-20 (96X96mm) is a Digital indicator suitable for panel mounting in control room. This is to be connected to WTI-10 using standard two core 2.5 sq. mm copper cable. The distance between WTI-10 and RWTI-20 can bemaximum of 1000 meters. RWTI-20 is supplied optionally on demand.

    RTD PT-100

    Temperature sensor (RTD PT-100) is housed in SS-304 tube with weatherproof terminal head for making electrical connections. It is provided with ½”bsp connection for fixing it on top plate of the transformer.