MasterTemp

• OLED display with 128 x 64 pixel graphics capability, contrast adjustment and background/text color inversion, readable under any lighting condition, including direct sunlight.

• IPD (Intelligent Presence Detector) standby function detects the user's presence and automatically turns on the high-resolution OLED display. This function extends the device display's service life, reduces internal power consumption and extends the service life of the entire electronic circuit. When the user comes within 1.5 meters of the device, the sensor detects their presence and the OLED display turns on automatically. This function is enabled by default, but the user can disable it in the “Configuration” menu.

• Main screen with simultaneous indication of 5 monitored quantities and the option to highlight selected quantities on the first line in SCAN mode;

• Clock with HMS indication retains its settings for up to 240 hours during a power outage and/or loss of power supply. It uses a supercapacitor for power backup, suitable for high operating temperatures and never requiring replacement;

• 5 navigation keys;

• 14 front-panel LEDs allow active output relays to be identified even from a distance;

• Written event and fault indications on the display (annunciator), with descriptions of the active relays;

• Intuitive menus for configuration, readings, actuations, maintenance and transformer parameters, password-protected and available in 2 languages (Portuguese and English);

• View maximum sensor temperatures in the readings menu;

• View the operating time of each cooling group in the readings menu;

• View the final temperature gradient of each transformer winding in the readings menu;

• View the load percentage of each transformer winding in the readings menu;

• View currents measured by the external CT (Split core / Clamp) in the readings menu;

• View transformer winding currents (calculated value) in the readings menu;

• View the loading of each transformer winding (calculated value) in the readings menu;

• View the loss of life and remaining life of each winding in the readings menu;

• Thermal image (hot-spot) calculation based on IEC 60076-7, IEEE C57.91 and NBR 5356-7:2017 standards;

• Calculation and display of transformer load percentage;

• Calculation of the final temperature gradient for the current load (oil-to-winding);

• Insulation loss-of-life calculation, selectable for Kraft (55°C), thermally stabilized (65°C) and Nomex (95°C) insulation, based on Arrhenius theory, with indication of remaining insulation life in hours and days.

• Temperature differential calculation between two PT100 sensors for monitoring tap changer faults or cooling efficiency.

• Fan operating time monitoring (hour meter) with a programmable maintenance reminder alarm;

• Front USB 2.0 communication port with Type-A connector for downloading and uploading settings using USEEASY software;

• 2-wire RS485 digital output (ANSI/TIA/EIA-485-A) with 2 available protocols, Modbus RTU and DNP3 (Level2), for remote monitoring through SCADA software, access to all measured parameters and actuation of digital outputs;

• Auto Baud Rate from 2,400 to 57,600 bps (automatically detects the communication network speed);

• Front slot for an 8 Gb Micro SD card, allowing storage of data measured and calculated by the Mastertemp for up to 10 years;

• Storage based on time and measurement variation, with a configurable recording interval from 5 to 180 minutes and a variation threshold to be disregarded from 1°C to 10°C and 100 mA to 1 A;

• Internal nonvolatile memory stores the maximum temperatures reached by the PT100 sensors and transformer windings;

• 3 permanent 0 to 10 ampere current measurement inputs for thermal image calculation, using an external CT (Split Core / Clamp) current transducer with a standard amplified 2-wire 4 to 20 mA analog output on its secondary. This allows installation up to 500 meters from the monitor without loss of accuracy (1%) or signal quality;

• 2 temperature measurement inputs for 3-wire PT100 sensors (EM 60751 – DIN 43760), with a measurement range from -50°C to 250°C, 0.25% (FS) accuracy and 1 decimal place indication. One input must be used to measure transformer top-oil temperature; the other can be configured for:

1. Tap changer oil temperature measurement with configurable differential alarm for tap changer fault detection.
2. Tank bottom or radiator outlet temperature measurement, indicating the differential relative to top-oil temperature, used to measure transformer cooling system efficiency;
3. Measurement of a second transformer top-oil temperature point, with indication of the average temperature from the two sensors and automatic backup if one sensor fails;
4. Ambient temperature measurement for use in calculating permissible transformer loading;

• 1 relay with a carrying capacity of 6 amperes for high oil temperature alarm, NO – Normally Open (NC – Normally Closed on request);

• 3 relays with a carrying capacity of 6 amperes for high winding temperature alarm, NO – Normally Open (NC – Normally Closed on request);

• 1 relay with a carrying capacity of 6 amperes for high oil temperature shutdown, NO – Normally Open (NC – Normally Closed on request), with programmable delay from 0 to 20 minutes;

• 1 relay with a carrying capacity of 6 amperes for monitor fault indication (Watchdog);

• 1 auxiliary relay with a carrying capacity of 6 amperes, programmable for alarms, shutdown or temperature differential;

• 3 relays with a carrying capacity of 6 amperes for cooling group or pump actuation, NO – Normally Open or NC – Normally Closed, with programmable hysteresis from 0 to 30°C and a 15-second timed interlock;