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.
WINDING TEMPERATURE INDICATOR / CONTROLLER (MODEL: WTI-10)
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, voltage class transformers.
REMOTE WINDING TEMPERATURE INDICATOR (MODEL: RWTI – 20)
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 be Maximum of 1000 meters. RWTI-20 is supplied optionally on demand.
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.