McMaster-Carr logo
    Filter by
    System of Measurement
    Relay Type
    Number of Circuits Controlled
    Mounting Location
    Switching Current
    Industrial Info Snippet
    Switch Designation
    Industrial Info Compare
    Reset Type
    Number of Terminals
    U.S.–Mexico–Canada Agreement (USMCA) Qualifying
    DFARS Specialty Metals
    Export Control Classification Number (ECCN)
    Industrial Info Snippet
    Switch Starting Position
    Industrial Info Compare
    Switch Action
    Industrial Info Compare
    Operation Type
    Enter e-mail addresses in the fields below
    Message
    Cancel
    Comments
    E-mail address (if you would like a response)
    19 Products

    High-Current-Monitoring Relays

    Image of ProductInUse. Front orientation. Monitoring Relays. High-Current-Monitoring Relays.
    Prevent AC current overload in equipment such as motors and heaters.
    These relays sense current flowing through wires routed through the opening. If the current exceeds a set trip point, the relay trips and starts the adjustable delay timer. After the timer's cycle, the relay cuts power to the equipment to protect against overload. Once current drops below the trip point, the relay allows power to flow again to the equipment.
    To determine the current trip range for more than one wire, divide the listed trip range by the number of wires passed through the opening.
    Current Trip for One
    Wire Range, amp
    Switch
    Designation
    Resistive Load Current
    @ AC Voltage
    Delay Time
    Range, sec.
    For Max.
    Wire Dia.
    Ht.
    Wd.
    Dp.
    Input AC
    Voltage, V AC
    Wire Connection
    Certification
    Mount
    Type
    Fasteners
    Included
    Mounting
    Hole Dia.
    No. of Mounting
    Holes
    Each
    Measures AC Current
    0.1 to 1SPDT
    10 amp @ 240V AC0.5 to 60.5"2.13"3.5"2.5"120Quick-Disconnect TerminalUL Recognized Component
    Screw OnNo0.19"265795K690000000
    1 to 10SPDT
    10 amp @ 240V AC0.5 to 60.5"2.13"3.5"2.5"120Quick-Disconnect TerminalC-UL Recognized Component, UL Recognized Component
    Screw OnNo0.19"265795K71000000
    3 to 30SPDT
    10 amp @ 240V AC0.5 to 60.5"2.13"3.5"2.5"120Quick-Disconnect TerminalC-UL Recognized Component, UL Recognized Component
    Screw OnNo0.19"265795K72000000
    6 to 60SPDT
    10 amp @ 240V AC0.5 to 60.5"2.13"3.5"2.5"120Quick-Disconnect TerminalC-UL Recognized Component, UL Recognized Component
    Screw OnNo0.19"265795K73000000
    10 to 100SPDT
    10 amp @ 240V AC0.5 to 60.5"2.13"3.5"2.5"120Quick-Disconnect TerminalC-UL Recognized Component, UL Recognized Component
    Screw OnNo0.19"265795K74000000
     

    Current-Monitoring Relays

    Image of Product. Front orientation. Contains Annotated. Monitoring Relays. Current-Monitoring Relays, Screw Terminals, Knob Adjustment.
    Image of Product. Front orientation. Contains Annotated. Monitoring Relays. Current-Monitoring Relays, Screw Terminals with IO-Link, Keypad Adjustment.
    Image of Product. Front orientation. Contains Annotated. Monitoring Relays. Current-Monitoring Relays, Spring-Clamp Terminals with IO-Link, Keypad Adjustment.

    Screw Terminals

    Knob Adjustment

    Screw Terminals

    with IO-Link,

    Keypad Adjustment

    Spring-Clamp

    Terminals with

    IO-Link, Keypad

    Adjustment

    Protect electrical equipment from overcurrent and undercurrent damage—these relays continuously monitor current flow. When current is outside a set range, they trip and cut power to prevent overheating, fire hazards, and stalling. Rated IP20, these relays have recessed terminals that keep fingers and other objects from touching live circuits. Mount them on a 35 mm DIN rail (also known as DIN 3 rail) for fast installation.
    Spring-Clamp-Terminal Wire Connection—Relays with spring-clamp terminals connect and disconnect to wire without screws. Because there’s no screw, these connections are less likely to loosen over time, even in high-vibration environments.
    IO-Link Communication Protocol—Relays with IO-Link can be programmed, monitored, and reset remotely by connecting them to a programmable logic controller (PLC), human-machine interface (HMI), or computer. If you want to program them locally, they have a keypad.
    Knob Adjustment—Relays with knob adjustments have knobs right on the front where you can set your trip current. You can see that they're wired correctly and when they're actuated based on the LED indicators.
    No. of
    Terminals
    Input Voltage
    Trip Current Setting, amp
    Trip Current,
    amp
    Trip Time,
    sec.
    Reset Type
    Switching Current
    @ Voltage
    Max. Switching
    Voltage
    Adjustment Mechanism
    Ht.
    Wd.
    Dp.
    Digital Display
    Type
    Each
    Screw Terminals
     
    1 Circuit Controlled with 1 Off or 1 On—SPDT
    924V AC, 24V DC0.1 to 1, 0.5 to 5, 0.8 to 80.1 to 30Automatic, Manual5 amp @ 240V AC
    5 amp @ 30V DC
    250V AC
    30V DC
    Knob3.5"0.9"3.9"8123N140000000
    9120V AC, 240V AC0.1 to 1, 0.5 to 5, 0.8 to 80.1 to 30Automatic, Manual5 amp @ 240V AC
    5 amp @ 30V DC
    250V AC
    30V DC
    Knob3.5"0.9"3.9"8123N13000000
     
    Screw Terminals with IO-Link
     
    1 Circuit Controlled with 1 Off or 1 On—SPDT
    924V DC0.05 to 100 to 999Automatic3 amp @ 240V AC
    1 amp @ 24V DC
    400V AC
    250V DC
    External Controller, Keypad3.6"0.9"3.4"LCD8123N11000000
     
    Spring-Clamp Terminals with IO-Link
     
    1 Circuit Controlled with 1 Off or 1 On—SPDT
    924V DC0.05 to 100 to 999Automatic3 amp @ 240V AC
    1 amp @ 24V DC
    400V AC
    250V DC
    External Controller, Keypad3.8"0.9"3.4"LCD8123N12000000
     

    Ground-Fault Monitoring Relays

    Image of Attribute. Front orientation. Contains Annotated. Monitoring Relays. Ground-Fault Monitoring Relays, Screw Terminals.
    Image of Attribute. Front orientation. Contains Annotated. Monitoring Relays. Ground-Fault Monitoring Relays, Screw Terminals, Knob Adjustment.

    Screw Terminals

    Screw Terminals

    Knob Adjustment

    Image of Attribute. Front orientation. Contains Annotated. Monitoring Relays. Ground-Fault Monitoring Relays, Screw Terminals with IO-Link.
    Image of Attribute. Front orientation. Contains Annotated. Monitoring Relays. Ground-Fault Monitoring Relays, Spring-Clamp Terminals with IO-Link.

    Screw Terminals with

    IO-Link

    Spring-Clamp

    Terminals with

    IO-Link

    Detect and mitigate ground faults to prevent harm to equipment, circuits, and people. These relays monitor the differential between incoming and outgoing current, also known as residual current. When the balance is off, they trip and cut power to the circuit. These relays are highly sensitive, so you can trust them to de-energize faulty circuits before a minor issue becomes a major one. Rated IP20, they have recessed terminals that keep fingers and other objects from touching live circuits. Mount them on 35 mm DIN rail (also known as DIN 3 rail) for fast installation.
    These relays require a current-indicating ring (sold separately) to operate. Choose a ring that is large enough for your lines to pass through. Feed the lines of the circuit through the center of the ring and connect the indicating ring output to the relay.
    Spring-Clamp-Terminal Wire Connection—Relays with spring-clamp terminals connect and disconnect to wire without screws. Because they don’t have screws, there’s less of a risk that they will loosen over time, even when they’re under vibration.
    IO-Link Communication Protocol—Relays with IO-Link can be programmed, monitored, and reset remotely by connecting them to a programmable logic controller (PLC), human-machine interface (HMI), or computer. If you want to program them locally, they have a keypad.
    Knob Adjustment—Relays with knob adjustments have knobs right on the front where you can set your trip current.
    LED Indicator—Relays with an LED indicator show the status of your relay, so you know it is wired correctly and when it is actuated.
    No. of
    Terminals
    Input Voltage
    Trip Current
    Setting, amp
    Trip Current,
    amp
    Trip Time,
    sec.
    Switching Current
    @ Voltage
    Max. Switching
    Voltage
    Adjustment Mechanism
    Ht.
    Wd.
    Dp.
    Features
    Each
    Screw Terminals
     
    2 Circuits Controlled with 2 Off or 2 On—DPDT
    1224V AC, 48V AC, 120V AC, 240V AC0.0305 amp @ 240V AC
    5 amp @ 24V DC
    250V AC
    24V DC
    3.2"1.4"2.6"LED Indicator8121N1010000000
    1224V AC, 48V AC, 120V AC, 240V AC0.305 amp @ 240V AC
    5 amp @ 24V DC
    250V AC
    24V DC
    3.2"1.4"2.6"LED Indicator8121N102000000
    1224V AC, 48V AC, 120V AC, 240V AC0.03 to 50 to 55 amp @ 240V AC
    5 amp @ 24V DC
    250V AC
    24V DC
    Knob3.2"1.4"2.8"LED Indicator8121N103000000
    1224V AC, 48V AC, 120V AC, 240V AC0.3 to 300 to 55 amp @ 240V AC
    5 amp @ 24V DC
    250V AC
    24V DC
    Knob3.2"1.4"2.8"LED Indicator8121N104000000
     
    Screw Terminals with IO-Link
     
    2 Circuits Controlled with 2 Off or 2 On—DPDT
    1224V DC0.03 to 400 to 9993 amp @ 240V AC
    1 amp @ 24V DC
    400V AC
    250V DC
    External Controller, Keypad4"0.9"3.6"Remote Reset8121N109000000
     
    Spring-Clamp Terminals with IO-Link
     
    2 Circuits Controlled with 2 Off or 2 On—DPDT
    1224V DC0.03 to 400 to 9993 amp @ 240V AC
    1 amp @ 24V DC
    400V AC
    250V DC
    External Controller, Keypad4.1"0.9"3.6"Remote Reset8121N111000000
     
    Current Indicating Rings
    back to top