DI – Digital Indicator

The digital indicator – DI is a microprocessor controlled unit for remote supervision of distinct transformer and power reactor variables.  It is possible to measure up to 8 variables.  For example, a DI can indicate various variables of one transformer: the insulating oil’s temperature and also the temperatures of 3 windings, oil moisture and oil water content. Otherwise, it can also indicate temperatures of phases A, B, C and spare of a single-phase bank of transformers.

The 8 indications are assigned to LEDs on the DI’s front panel. The input variables are individually configured by the user by configuration of the scale measurement limits. The alarm limit for each variable is programmable in two levels. In the event of a variable exceeding its limit, the correspondent LED starts to blink and a relay can be configured to alarm a remote system.

DI has an analog output for remote indication, reflecting one user configured variable. It also has a serial communication port RS485, with Modbus   RTU protocol (standard) or DNP3.0 (optional), whichfacilitates the remote communication of variable values and changes in the alarm limits.

Main Features:

• IED (Intelligent Electronic Device) designed specifically for substation yard conditions (interference, extreme temperatures), IP40 protection level;

• Real-Time variable indication on display, with programmable display mode: automatic screen roll and fixed channel reading indication;

• High-glow LED type display for easy visualization;

• Serial communication port RS485 for integration with supervision or remote monitoring systems. Open communication protocols   Modbus   RTU or DNP3.0with 1ms Time-Stamp support;

• Current loop signal input: -20…20, -10…10, -5…5, -1…1, 0…1, 0…5, 0…10, 0…20or 4…20mA, configurable by the user;

• 1 Programmable analog output for remote reading.  Programmable current loop output range: -20…20, -10…10, -5…5, -1…1,0…1, 0…5, 0…10, 0…20   or 4…20mA;

• Output relays for two levels alarm indication (NO or NC contact), internal fault (NC);

• Internal clock with date and timeand non-volatile memory for storage of readings (optional);The user selects the variable groups to be stored and the recording can be initiated by:

– Time interval between recordings;

– Variation of any variable;

– State change of any output relay.

• Self-diagnostic for internal fault detection. Total absence of mechanical parts for parameter setting and calibration.