NMC Automatic Voltage Regulating Relays

Nmc’s microcontroller based automatic voltage regulating relays (avr relays) are latest technology based relays used for regulating the secondary voltage of power transformers with on load tap changer (oltc). The parameter settings are made through the front panel keys & are stored in nvram. Independent time delays can be set for first control pulse & subsequent pulses. Built-in tap displays tap number of power transformer. Oltc is blocked for uv, ov, oc, cf, minmax tap positions & tap fail . In manual mode, tap raiselower can be achieved through front keys. In test mode, relays, display and led indications can be checked. A pair of contacts are available for raise, lower, uv, ov, manual mode, cf, tf & oc. There are two nos. Of 5 amps c.t.’s available, one for the over current blocking and l.d.c. & other for measuring the current.
features :
ø microcontroller based architecture with ad converter.
Ø password protected.
Ø auxiliary supply : 85v-265v acdc
ø linear or inverse time response.
Ø relay “on timer”
ø built-in tap position indicator upto 40 taps.
Ø readout of primary secondary voltages, current & tap no.
Ø readout of kv ki voltage & current.
Ø 7 segment bright red led displays.
Ø independent lower, raise & nominal value settings.
Ø blocking for uv, ov, oc, control fail, tap fail & minmax tap no.
Ø auto manual mode of operation.
Ø test mode & factory reset mode.
Ø single pulse or continuous pulse operation.
Ø line drop compensator (l.d.c.).
Ø data logging.
Ø modbus rs 485
ø rtc
ø 4-20ma output from pt voltage & tpi for scada.
Ø pt display of 433v instead of 110v.
Ø over current blocking.
Ø additional c.t. For measuring the current
ø blocking for min. & max. Tap no.
Ø master slave features.