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  • Description
  • Features
  • Applications
  • Ordering Info
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  • Accessories

  • VME420

    Digital voltage and frequency relay for single-phase AC and DC systems

    The VME420 is a powerful, all-in-one unit for single-phase AC and DC systems for 0 to 300 V monitoring over/undervoltage and over/underfrequency. Values are displayed and changed via a digital seven-segment display and menu. Values are displayed as true RMS values, and many different delays can be set.

    The VME420 unit utilizes an auxiliary supply voltage to power itself. For the version that is powered off of the monitored line, please see the VME421H.

  • Key Features: VME420

    • Overvoltage, undervoltage, overfrequency, and underfrequency monitoring for single-phase AC and DC systems
    • True RMS readings
    • Digital display with values shown in real-time
    • Separately adjustable alarms for each alarm type
    • Onboard menu for settings; explicit trip values can be entered in
    • Two SPDT contact outputs, independently configurable to any combination of alarm types
    • Separately adjustable time delays for response delay, startup delay, and delay on release
    • Built-in test and reset buttons
    • Latching or non-latching operation, selectable
    • Normally energized or normally de-energized operation, selectable
    • Last tripped alarm value stored in memory
    • Auxiliary supply voltage inputs

  • Applications: VME420

    • General applications requiring overvoltage / undervoltage protection
    • Generators, portable and fixed
    • Battery backup systems
    • Motor overvoltage protection

  • Ordering information: VME420

    NameSystem Voltage0...400 μA analog output0(4)...20 mA analog output0...10 V analog outputSPDT contact outputSupply VoltageOrdering Number
    VME420-D-1AC 0...300 V (15...460 Hz) DC 0...300 V 2AC 16...72 V (15...460 Hz) DC 9.6...94 V B93010001
    VME420-D-2AC 0...300 V (15...460 Hz) DC 0...300 V 2AC 70...300 V (15...460 Hz) DC 70...300 V B93010002
    VME420-DM-1AC 0...300 V (15...460 Hz) DC 0...300 V 1AC 16...72 V (15...460 Hz) DC 9.6...94 V B93010015
    VME420-DM-2AC 0...300 V (15...460 Hz) DC 0...300 V 1AC 70...300 V (15...460 Hz) DC 70...300 V B93010016

  • Downloads: VME420

    Document Name Language Date Download
    Technical Bulletin / Datasheet
    VME420    		 English 02.2010
    Download
    Installation Bulletin
    VME420    		 English 10.2012
    Download
    User Manual
    VME420    		 English 12.2009
    Download
    Brochure
    Overview - Protection Relays    		 English 04.2013
    Download
    3D STEP Drawing
    420 Series (Standard)    		 N/A 06.2013
    Download

  • Accessories: VME420

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  • VMD420

    Digital voltage and frequency relay for three-phase AC systems

    The VMD420 is a powerful, all-in-one unit for monitoring three-phase AC systems up to 500 V. The VMD420 is capable of monitoring for overvoltage and undervoltage, overfrequency and underfrequency, asymmetry, phase sequence, and phase loss. Values are displayed and changed via a digital seven-segment display and menu. Values are displayed as true RMS values, and many different delays can be set.

    The VMD420 unit utilizes an auxiliary supply voltage for power. For the version that is powered off of the monitored line, please see the VMD421H.

  • Key Features: VMD420

    • Overvoltage, undervoltage, overfrequency, and underfrequency, asymmetry, phase sequence, and phase loss monitoring for three-phase AC systems
    • True RMS readings
    • Digital display with values shown in real-time
    • Separately adjustable alarms for each alarm type
    • Onboard menu for settings; explicit trip values can be entered in
    • Two SPDT contact outputs, independently configurable to any combination of alarm types
    • Separately adjustable time delays for response delay, startup delay, and delay on release
    • Built-in test and reset buttons
    • Latching or non-latching operation, selectable
    • Normally energized or normally de-energized operation, selectable
    • Last tripped alarm value stored in memory
    • Auxiliary supply voltage inputs

  • Applications: VMD420

    • General applications requiring overvoltage / undervoltage protection
    • Generators, portable and fixed
    • Monitoring of industrial distribution systems
    • Motor overvoltage and phase loss protection

  • Ordering information: VMD420

    NameSystem Voltage0...400 μA analog output0(4)...20 mA analog output0...10 V analog outputSPDT contact outputSupply VoltageOrdering Number
    VMD420-D-1AC 0...500 V (15...460 Hz) 2AC 16...72 V (42...460 Hz) DC 9.6...94 V B93010005
    VMD20-D-2AC 0...500 V (15...460 Hz) 2AC 70...300 V (42...460 Hz) DC 70...300 V B93010006
    VMD420-DM-1AC 0...500 V (15...460 Hz) 1AC 16...72 V (42...460 Hz) DC 9.6...94 V B93010017
    VMD420-DM-2AC 0...500 V (15...460 Hz) 1AC 70...300 V (42...460 Hz) DC 70...300 V B93010018

  • Downloads: VMD420

    Document Name Language Date Download
    Technical Bulletin / Datasheet
    VMD420    		 English 04.2011
    Download
    Installation Bulletin
    VMD420    		 English 10.2012
    Download
    User Manual
    VMD420    		 English 01.2010
    Download
    Brochure
    Overview - Protection Relays    		 English 04.2013
    Download
    3D STEP Drawing
    420 Series (Standard)    		 N/A 06.2013
    Download

  • Accessories: VMD420

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  • VME421H

    Digital voltage and frequency relay for single-phase AC and DC systems

    The VME421H is a powerful, all-in-one unit for single-phase AC and DC systems for up to 300 V, monitoring over/undervoltage and over/underfrequency. Values are displayed and changed via a digital seven-segment display and menu. Values are displayed as true RMS values, and many different delays can be set.

    The VME421H unit powers itself off of the line being monitored. For the version that utilizes an external supply voltage, please see the VME420.

  • Key Features: VME421H

    • Overvoltage, undervoltage, overfrequency, and underfrequency monitoring for single-phase AC and DC systems
    • True RMS readings
    • Digital display with values shown in real-time
    • Separately adjustable alarms for each alarm type
    • Onboard menu for settings; explicit trip values can be entered in
    • Two SPDT contact outputs, independently configurable to any combination of alarm types
    • Separately adjustable time delays for response delay, startup delay, and delay on release
    • Built-in test and reset buttons
    • Latching or non-latching operation, selectable
    • Normally energized or normally de-energized operation, selectable
    • Last tripped alarm value stored in memory
    • Powers itself from monitored lines

  • Applications: VME421H

    • General applications requiring overvoltage / undervoltage protection
    • Generators, portable and fixed
    • Battery backup systems
    • Motor overvoltage protection

  • Ordering information: VME421H

    Name0...400 μA analog output0(4)...20 mA analog output0...10 V analog outputSPDT contact outputSupply VoltageOrdering Number
    VME421H-D-12AC 9.6...150 V (15...460 Hz) DC 9.6...150 V B93010003
    VME421H-D-22AC 70...300 V (15...460 Hz) DC 70...300 V B93010004
    VME420-DM-11AC 9.6...150 V (15...460 Hz) DC 9.6...150 V B93010024
    VME420-DM-21AC 70...300 V (15...460 Hz) DC 70...300 V B93010010

  • Downloads: VME421H

    Document Name Language Date Download
    Technical Bulletin / Datasheet
    VME421H    		 English 03.2013
    Download
    Installation Bulletin
    VME420    		 English 10.2012
    Download
    User Manual
    VME421H    		 English 01.2010
    Download
    Brochure
    Overview - Protection Relays    		 English 04.2013
    Download

  • Accessories: VME421H

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  • VMD421H

    Digital voltage and frequency relay for three-phase AC systems

    The VMD421H is a powerful, all-in-one unit for monitoring three-phase AC systems up to 500 V. The VMD420 is capable of monitoring for overvoltage and undervoltage, overfrequency and underfrequency, asymmetry, phase sequence, and phase loss. Values are displayed and changed via a digital seven-segment display and menu. Values are displayed as true RMS values, and many different delays can be set.

    The VMD421H unit powers itself off of the line being monitored. For the version that utilizes an external supply voltage, please see the VMD420.

  • Key Features: VMD421H

    • Overvoltage, undervoltage, overfrequency, and underfrequency, asymmetry, phase sequence, and phase loss monitoring for three-phase AC systems
    • True RMS readings
    • Digital display with values shown in real-time
    • Separately adjustable alarms for each alarm type
    • Onboard menu for settings; explicit trip values can be entered in
    • Two SPDT contact outputs, independently configurable to any combination of alarm types
    • Separately adjustable time delays for response delay, startup delay, and delay on release
    • Built-in test and reset buttons
    • Latching or non-latching operation, selectable
    • Normally energized or normally de-energized operation, selectable
    • Last tripped alarm value stored in memory
    • Powers itself from monitored lines

  • Applications: VMD421H

    • General applications requiring overvoltage / undervoltage protection
    • Generators, portable and fixed
    • Monitoring of industrial distribution systems
    • Motor overvoltage and phase loss protection

  • Ordering information: VMD421H

    NameSystem Voltage0...400 μA analog output0(4)...20 mA analog output0...10 V analog outputSPDT contact outputOrdering Number
    VMD421H-D-3AC 70...500 V (15...460 Hz) 2B93010007
    VMD421H-DM-3AC 70...500 V (15...460 Hz) 1B93010023

  • Downloads: VMD421H

    Document Name Language Date Download
    Technical Bulletin / Datasheet
    VMD421H    		 English 10.2011
    Download
    Installation Bulletin
    VMD421H    		 English 10.2012
    Download
    User Manual
    VMD421H    		 English 03.2010
    Download
    Brochure
    Overview - Protection Relays    		 English 04.2013
    Download

  • Accessories: VMD421H

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  • GM420

    Digital ground continuity relay for AC systems

    The GM420 monitors the ground conductor loop in AC systems. Three types of alarms may be used - a line resistance value (0...100 Ω), an OL alarm (when a very high resistance or break in the loop is detected), and an extraneous voltage between the two monitoring terminals. The loop resistance is displayed on the LCD screen in real-time. Two SPDT contact outputs are included and may be set to any combination of the alarms.

  • Key Features: GM420

    • Ground continuity monitoring in AC systems
    • Alarms for line resistance (0...100 Ω), break in the loop, and extraneous voltage
    • Line resistance displayed in real-time on the digital display
    • Onboard menu for settings; explicit trip values can be entered in
    • Two SPDT contact outputs, independently configurable to any combination of alarm types
    • Separately adjustable time delays for response delay, startup delay, and delay on release
    • Built-in test and reset buttons
    • Latching or non-latching operation, selectable
    • Normally energized or normally de-energized operation, selectable
    • Last triggered alarm value stored in memory
    • Auxiliary supply voltage inputs

  • Applications: GM420

    • General applications requiring ground monitoring
    • Portable equipment
    • Trailer docks and loading areas
    • Motor overvoltage and phase loss protection

  • Ordering information: GM420

    Name0...400 μA analog output0(4)...20 mA analog output0...10 V analog outputSPDT contact outputSupply VoltageOrdering Number
    GM420-D-12AC 16...72 V (42...460 Hz) DC 9.6...94 V B93082001
    GM420-D-22AC 70...300 V (42...460 Hz) DC 70...300 V B93082002

  • Downloads: GM420

    Document Name Language Date Download
    Technical Bulletin / Datasheet
    GM420    		 English 04.2011
    Download
    Installation Bulletin
    GM420    		 English 10.2012
    Download
    User Manual
    GM420    		 English 09.2007
    Download
    Brochure
    Overview - Protection Relays    		 English 04.2013
    Download
    3D STEP Drawing
    420 Series (Standard)    		 N/A 06.2013
    Download

  • Accessories: GM420

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  • CME420

    Digital current relay for AC systems

    The CME420 monitors for undercurrent and overcurrent in AC systems, as well as the current between two threshold values. True RMS values are read by the device. Current is displayed in real-time on the digital display. Trip values are explicitly set via the device's built-in menu. Two separate SPDT contacts are available, which can be set for normally energized or normally deenergized operation, latching or non-latching. An external supply voltage is utilized to power the device.

    When directly connecting the CME420 to the circuit, up to 16 A of current may be monitored. When connecting an X/5 type current transformer, the ratio of the CT may be entered into the device's settings. This allows explicit values to be entered and displayed of up to 999 A without any hand calculations required.

  • Key Features: CME420

    • Overcurrent and undercurrent monitoring in AC systems
    • Current monitoring between two threshold values
    • Current displayed in real-time on the digital display
    • Direct system connection for monitoring up to 16 A
    • Current transformer connection for monitoring up to 999 A
    • CT ratio entered into device allows for explicit value setting and display
    • Onboard menu for settings; explicit trip values can be entered in
    • Two SPDT contact outputs, independently configurable to any combination of alarm types
    • Separately adjustable time delays for response delay, startup delay, and delay on release
    • Built-in test and reset buttons
    • Latching or non-latching operation, selectable
    • Normally energized or normally de-energized operation, selectable
    • Last triggered alarm value stored in memory
    • Auxiliary supply voltage inputs

  • Applications: CME420

    • General applications requiring overcurrent and undercurrent protection
    • Generators, portable and fixed
    • Monitoring of industrial distribution systems
    • Motor overcurrent monitoring

  • Ordering information: CME420

    Name0...400 μA analog output0(4)...20 mA analog output0...10 V analog outputSPDT contact outputSupply VoltageOrdering Number
    CME420-D-12AC 16...72 V (42...460 Hz) DC 9.6...94 V B93060001
    CME420-D-22AC 70...300 V (42...460 Hz) DC 70...300 V B93060002
    CME420-DM-11AC 16...72 V (42...460 Hz) DC 9.6...94 V B93060003
    CME420-DM-21AC 70...300 V (42...460 Hz) DC 70...300 V B93060004

  • Downloads: CME420

    Document Name Language Date Download
    Technical Bulletin / Datasheet
    CME420    		 English 03.2011
    Download
    Installation Bulletin
    CME420    		 English 10.2012
    Download
    User Manual
    CME420    		 English 09.2006
    Download
    Brochure
    Overview - Protection Relays    		 English 04.2013
    Download
    3D STEP Drawing
    420 Series (Standard)    		 N/A 06.2013
    Download

  • Accessories: CME420

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  • CMD420

    Digital current relay for three-phase AC systems (1 A secondary CTs)

    The CMD420 monitors for overcurrent and/or undercurrent in three-phase AC systems. Current is measured as true RMS values. Values are shown in real-time on the device's LCD display. The current on each phase may be displayed independently by pressing the UP and DOWN buttons on the device. Each alarm type can be independently activated or deactivated based on the system requirements. Three separate time delays (startup, alarm response, and delay on release) allow the CMD420 to be tailored to specific applications. Two SPDT alarm contacts may be assigned any combination of alarms.

    Measurements are taken via external current transformers, one per phase. Alarm values are entered based on the secondary of the current transformer (0 - 1 A). Once the ratio is entered into the device, values shown on the display will be based on the primary of the current transformer - no mental calculations required. Ratios up to 2000:1 may be used with the device.

    The CMD420 uses x/1 type current transformers (1 A secondary). For use with current transformers with a 5 A secondary, see the CMD421.

  • Key Features: CMD420

    • Overcurrent and undercurrent monitoring in three-phase AC systems
    • Current monitoring between two threshold values
    • Current displayed in real-time on the digital display
    • Current transformer connection for monitoring up to 2000 A
    • CT ratio entered into device allows for explicit value setting and display
    • Onboard menu for settings
    • Two SPDT contact outputs, independently configurable to any combination of alarm types
    • Separately adjustable time delays for response delay, startup delay, and delay on release
    • Built-in test and reset buttons
    • Latching or non-latching operation, selectable
    • Normally energized or normally de-energized operation, selectable
    • Last triggered alarm value stored in memory
    • Auxiliary supply voltage inputs

  • Applications: CMD420

    • General applications requiring overcurrent and undercurrent protection
    • Generators, portable and fixed
    • Monitoring of industrial distribution systems
    • Motor overcurrent monitoring

  • Ordering information: CMD420

    NameSupply VoltageOrdering Number
    CMD420-D-1AC 16...72 V (42...460 Hz) DC 9.6...94 V B93060006
    CMD420-D-2AC 70...300 V (42...460 Hz) DC 70...300 V B93060007

  • Downloads: CMD420

    Document Name Language Date Download
    Technical Bulletin / Datasheet
    CMD420 / CMD421    		 English 01.2013
    Download
    Installation Bulletin
    CMD420 / CMD421    		 English 01.2013
    Download
    Brochure
    Overview - Protection Relays    		 English 04.2013
    Download
    3D STEP Drawing
    420 Series (Standard)    		 N/A 06.2013
    Download

  • Accessories: CMD420

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  • CMD421

    Digital current relay for three-phase AC systems (5 A secondary CTs)

    The CMD421 monitors for overcurrent and/or undercurrent in three-phase AC systems. Current is measured as true RMS values. Values are shown in real-time on the device's LCD display. The current on each phase may be displayed independently by pressing the UP and DOWN buttons on the device. Each alarm type can be independently activated or deactivated based on the system requirements. Three separate time delays (startup, alarm response, and delay on release) allow the CMD421 to be tailored to specific applications. Two SPDT alarm contacts may be assigned any combination of alarms.

    Measurements are taken via external current transformers, one per phase. Alarm values are entered based on the secondary of the current transformer (0 - 5 A). Once the ratio is entered into the device, values shown on the display will be based on the primary of the current transformer - no mental calculations required. Ratios up to 2000:5 may be used with the device.

    The CMD421 uses x/5 type current transformers (5 A secondary). For use with current transformers with a 1 A secondary, see the CMD420.

  • Key Features: CMD421

    • Overcurrent and undercurrent monitoring in three-phase AC systems
    • Current monitoring between two threshold values
    • Current displayed in real-time on the digital display
    • Current transformer connection for monitoring up to 2000 A
    • CT ratio entered into device allows for explicit value setting and display
    • Onboard menu for settings
    • Two SPDT contact outputs, independently configurable to any combination of alarm types
    • Separately adjustable time delays for response delay, startup delay, and delay on release
    • Built-in test and reset buttons
    • Latching or non-latching operation, selectable
    • Normally energized or normally de-energized operation, selectable
    • Last triggered alarm value stored in memory
    • Auxiliary supply voltage inputs

  • Applications: CMD421

    • General applications requiring overcurrent and undercurrent protection
    • Generators, portable and fixed
    • Monitoring of industrial distribution systems
    • Motor overcurrent monitoring

  • Ordering information: CMD421

    NameSupply VoltageOrdering Number
    CMD421-D-1AC 16...72 V (42...460 Hz) DC 9.6...94 V B93060008
    CMD421-D-2AC 70...300 V (42...460 Hz) DC 70...300 V B93060009

  • Downloads: CMD421

    Document Name Language Date Download
    Technical Bulletin / Datasheet
    CMD420 / CMD421    		 English 01.2013
    Download
    Installation Bulletin
    CMD420 / CMD421    		 English 01.2013
    Download
    Brochure
    Overview - Protection Relays    		 English 04.2013
    Download
    3D STEP Drawing
    420 Series (Standard)    		 N/A 06.2013
    Download

  • Accessories: CMD421

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  • IR420-D6

    Digital offline ground fault monitor for grounded and ungrounded systems

    The IR420-D6 monitors for ground faults on offline loads and circuits on grounded or ungrounded AC systems. The IR420-D6 monitors the system‘s insulation resistance to detect if any faults are present on the offline load. A digital display shows the insulation resistance reading in real-time. Two SPDT contact outputs are available for remote alarm indication.

    An external supply voltage is required to power the device. See ordering information for available supply voltages. High system voltages require the use of the AGH520S voltage coupler.

  • Key Features: IR420-D6

    • Ground fault monitoring for offline grounded and ungrounded systems
    • Two separately adjustable insulation resistance response values
    • Digital display showing readings in real-time
    • Easy-to-use, onboard menu for managing settings
    • Built-in test and reset button
    • Connections for external test and reset
    • Latching or non-latching operation, selectable
    • Two SPDT contact outputs, normally energized or normally de-energized operation
    • Meets requirements for ground detectors in accordance with NEC 250.21(B) and CEC 10-106(2)

  • Applications: IR420-D6

    • Single-phase or three-phase, offline AC systems
    • Offline motors and pumps
    • General loads with extended periods of offline time

  • Ordering information: IR420-D6

    NameResponse ValueSupply VoltageOrdering Number
    IR420-D6-110...20000 kΩ AC 16...72 V (42...460 Hz) DC 9.6...94 V B91016415
    IR420-D6-210...20000 kΩ AC 70...300 V (42...460 Hz) DC 70...300 V B91016407

  • Downloads: IR420-D6

    Document Name Language Date Download
    Technical Bulletin / Datasheet
    IR420-D6    		 English 01.2012
    Download
    Brochure
    Overview - Protection Relays    		 English 04.2013
    Download

  • Accessories: IR420-D6

    Voltage Couplers

    Voltage coupler for ungrounded AC systems 0...7200 V

    NameOrdering Number
    AGH520SB913033