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DPR-145 is a precision unit designed for the temperature protection of dry type or resin filled MV transformers. The unit offers a high degree of protection against electromagnetic disturbances.

The unit has 4 temperature inputs of PT100 type.

Three of them are used for the transformer protection. The fourth input may be used as core temperature protection or ambient temperature monitoring.

Alarm and trip levels of the unit are independently adjustable for first 3 sensors and the fourth sensor input.

Alarm levels are adjusted using the program mode. If no operation is performed, then the unit will exit program mode in 3 minutes.


The unit offers a cable compensation function in order to prevent long cables from impairing the measurement precision.

The unit has 4 dry contact relay outputs rated 5A.

FAN: provides cooler fan control
TRIP: high temperature failure relay
ALARM: pre-alarm relay
FAULT: sensor or internal failure indicator

The unit offers an automatic self test feature. The self test consists on the verification of sensor inputs and internal memory integrity.

The standard isolated RS-485 MODBUS RTU communication port is not affected by ground potential differences and allows safe transfer of information to remote management and automation systems.

The supply input is isolated from sensor connections. The unit has 2 supply options, being 19-150VDC or 85-305VAC.

1 degrees C measurement precision

4 x PT100 analog inputs

Allows cable length compensation

Automatic detection of sensor failures

Automatic and manual self test

4 x relay outputs, 5A/250Vac

Fully isolated RS-485 serial port

MODBUS-RTU communication

Recording of maximum temperatures

Front panel programmable

2 alarm thresholds for channels 1-2-3

2 alarm thresholds for channel 4

Easy to read, 3 digit 14mm led display

Wide supply voltage range: 19-150VDC

AC supply version available (85-305VAC)

Reduced panel depth, easy to install

Wide operating temperature range, -20 to +70°C

Sealed front panel (IP65 with gasket)

2 part connection system

Product Brochure

User Manual

User Manual (Version 1.0)

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