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  • Fully designed in Iran
  • Designed for Medium voltage protection
  • Precise detection of inrush current
  • Capable to detect CT saturation
  • Cold load pick up protection
  • Capable to record 20 fault waveforms 
  • Up to 1000 event recorder

Relay Hafez 121 is designed and built based on IEC 60255 standard. This relay fully designed based on Iranian experts’ knowledge, all algorithm fulfills Iran electrical distribution network requirements and make it more profitable than others countries relays. 
  • Two stages in delayed protection ANSI 51 with standard curve
  • Two stages in instantaneous or constant time Protectionism ANSI 50
  • One stage delayed Earth fault Protection with standard cure ANSI 51N
  • two stages Instantaneous Earth fault Protection ANSI 50N
  • Thermal overload protection ANSI 49
  • Two stages negative sequence protection ANSI46
  • Broken conductor Protection unit
  • Demand control
  • Circuit breaker failure unit ANSI 50
  • Wear condition and number of Circuit breaker operation
  • Auto reclose ANSI 79
  • Cold load pickup ANSI51c
  • Inrush blocking unit
  • Trip Circuit Supervision (TCS)
  • Instantaneous overcurrent (<<<I) or Instantaneous Earth fault error (<<<I0) with under one cycle operation
  • Improved Instantaneous unit Stability Negative sequence and earth fault in CT saturation
  • Enhanced inrush current detection while CT saturation
  • Smart and fast setting for distribution transformer setting
  • Enhance transformer thermometer operation for trip and alarm command
  • Smart Recloser
  • Circuit breaker chamber age estimator and operation mechanism
  • Choose calculation method of current amplitude with first harmonic and True-RMS
  • Relay characterization and reset time
  • Mode bus RTU communication protocol
  • Connect with a computer program with an Ethernet port (TCP/IP)
  • User-friendly GUI for communicating with relay (setting, configuration, Fault waveform visualization, etc.)
  • Recording events and faults
  • Record current waveforms of fault 
  • Solar and Christian calendar
  • Two programmable digital input
  • 5 programmable digital output
  • 8 signal LEDs ( 3 fixed usage – 5 programmable)
  • Changeable password
  • Having a metal box with electrostatic dye

Address: University of Tehran Science & Technology Park, North Kargar st., Tehran, Iran
Phone Number: +98 (21) 88013196
Postal Code: 1439817435
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