BB211-RS485 + TPL503 Temperature Pressure and Level Monitor

TThe new control unit BB211-RS485 with the TPL503 sensor provides the most modern protection for the protection of hermetically sealed oil transformers. The old electromechanical devices of the past, like float switches are replaced by the TPL503 which, installed directly on the transformer

The BB211 controller combined with the TPL503 sensor provide the highest level of protection for hermetic oil filled transformers. The TPL503 replaces the classic electromechanical controls (float switches) of the past and is installed directly on the transformer via an integrated flange allowing it to monitor the oil temperature, pressure and level. The sensor has a transparent body which allows you to see the oil level from any direction around the sensor, making it easy to visually check the oil level. The sensor is connected to the BB211 controller via a 4-pin powerlink cable, with M12 connector (maximum length 40m)

On request, a protective coating can be applied to the electronics board for tropical climates.


    • Temperature monitoring from -40°C to 120°C (32° – 248°F)
    • Temperature resolution 1°C
    • Pressure monitoring from -400 to +500mbar (-5.8 to +7.25psi) (Control from 0 to +500mbar) Resolution 10mbar
    • Level control in 3 modes: FULL, ALARM, TRIP
    • 85-260V AC/DC input power. 50/60Hz
    • VDC with reversible polarities
    • Rated for use in ambient temperatures from -20° to +60°C (-4° to 140°F)
    • Digital input for connection to TPL503 sensor
    • All potential free output relays rated for up to 5A @ 250VAC
    • 1 alarm relay (Alarm/Fault)
    • 1 alarm relay (Trip)
    • Modbus RS485output
    • Protection against electromagnetic noise according to CEI-EN61000-4-4

      TPL503 sensor

      The TPL503 sensor monitors oil temperature, pressure and level