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Automatic Mains Failure Relay (AMF)


  • Accuracy Class 1.0
  • Displays voltage, frequency and current.
  • Large 20 X 4 backlit LC Display
  • CT Ratio field programmable
  • 12 LEDs for different indications
  • DG maintenance warning
  • Low battery warning
  • Generator Over Current Alarm
  • Generator trial fail alarm
  • DG fault alarm
  • DG test mode
  • Over volt indication
  • Under volt Indication
  • Automatic contactor control
  • Displays Generator (DG) Run Hour and Maintenance Hour
  • Suitable for both 12V and 24V battery systems. Wide input (9-36VDC) DC-DC converter power supply.

The AMF relay is a micro-controller based unit which automates generator start and stop actions during mains failure by controlling both mains and generator contactors. It also measures voltage, current and frequency and displays it on a 20 x 4 LCD. It has 12 LEDs for different indications. All programmable parameters are password protected and are stored in a non volatile memory and thus all information is retained in the event of complete loss of battery power. AMF can be operated in "AUTO","QAUTO" (Quick Auto) or "MANUAL" mode. The unit features a non-erasable incremental "DG run hour" and "maintenance hour. This unit is meant for use in three phase four wire systems. The "CT ratio" is site selectable. The unit is powered by a wide input (9-36VDC) power supply, which makes it suitable for both 12V and 24V battery systems.

Technical Specifications

Three Phases and Neutral of a 3P4W
Voltage Direct Voltage Input: Up to 300V L-N
Burden: 0.5VA
Current Secondary Current Input : 5A or 1A (Site Selectable)
CT Ratio : Site Selectable
Range of Reading : 5 – 5000A
Burden : < 1.0VA
Overload : 5A CT = 6A RMS Continuous
1A CT = 1.2A RMS Continuous
Power Supply 9-36V DC
Output Relay Six Relays(NO)
Switching Voltage : Max. 250 VAC
Switching Current : 6 A (Resistive load)
Expected Mechanical Life : >1X10 switching operations
Expected Electrical Life : > 5X10 switching operations
Measurment True RMSBasicParameters Voltage (Volts L-N ) VL-N Accuracy : 1.0% of Reading
Current(Amps IR, IY, IB) Accuracy : 0.25 % of Reading
Line Frequency 45 to 55 Hz, Accuracy : 0.3% of Reading
Dimensions Bezel 144 X 144 mm
Panel Cutout 138 X 138 mm
Depth of installation 55 mm
Display 20 X 4 Backlit LCD
Operating temp 10°C to 50°C
Weight 0.58 Kgs (Approx.)
Operating Current Range 0.4% to 120% of CT primary

Connection Diagram