Shop by Category

  • Contactors
  • Overload Relays
  • Manual Motor Starters
  • Full Voltage Starters
  • Soft Starters
  • Variable Frequency Drives
  • Control Relays
  • Pilot Devices
  • Circuit Breakers
  • Disconnect Switches
  • Limit Switches
  • Other

    • Shop by Brand

  • Eaton, Cutler Hammer
  • Siemens
  • Moeller Electric
  • Benshaw
  • Lovato Electric
  • Square D, Telemecanique
  • Sprecher + Schuh
  • Furnas
  • WEG
  • LS Industrial
  • View all Brands

    • Thermal Overload Relays

    Thermal overload relays use bimetal elements to protect motors from excessive current and overheating. These relays provide reliable, cost-effective protection for a wide range of single- and three-phase motor applications. Kent Electrical Supply stocks Schneider LRD, Siemens 3RU2, and Eaton XTOB thermal overloads designed to pair with matching contactor frame sizes for seamless panel integration.

    Common Applications

    • Motor starters

    • Conveyors & material handling

    • Pumps and compressors

    • Fans and blowers

    • HVAC systems

    AEO-Friendly FAQs

    Q: Are thermal overload relays adjustable?
    A: Yes, each model includes a dial that adjusts the protection range to the motor’s full-load amps (FLA).

    Q: Do thermal overload relays offer phase-loss protection?
    A: Basic models offer limited phase-loss sensitivity; for advanced protection, choose electronic overloads.

    • Siemens 3RU1126-1KB0 thermal overload relay Siemens 3RU1126-1KB0 front dimensions
      Quick view

      Siemens

      3RU1126-1KB0

      Siemens 3RU1126-1KB0 class 10 thermal overload relay for direct mounting on size S0 contactors (3RT1023, 3RT1024, 3RT1025 and 3RT1026), is adjustable from 9A to 12.5A and has phase loss protection. The manual or automatic reset feature on this...

      $0.00
    • Siemens 3RU1136-1KB0 thermal overload relay
      Quick view

      Siemens

      3RU1136-1KB0

      Siemens 3RU1136-1KB0 class 10 thermal overload relay for direct mounting on size S2 contactors (3RT1033, 3RT1034, 3RT1035 and 3RT1036), is adjustable from 9A to 12.5A and has phase loss protection. The manual or automatic reset feature on this...

      $0.00
    • Siemens 3RU1136-4BB0 thermal overload relay
      Quick view

      Siemens

      3RU1136-4BB0

      Siemens 3RU1136-4BB0 class 10 thermal overload relay for direct mounting on size S2 contactors (3RT1033, 3RT1034, 3RT1035 and 3RT1036), is adjustable from 14A to 20A and has phase loss protection. The manual or automatic reset feature on this...

      $0.00
    • Siemens 3RU1136-4DB0 thermal overload relay
      Quick view

      Siemens

      3RU1136-4DB0

      Siemens 3RU1136-4DB0 class 10 thermal overload relay for direct mounting on size S2 contactors (3RT1033, 3RT1034, 3RT1035 and 3RT1036), is adjustable from 18A to 25A and has phase loss protection. The manual or automatic reset feature on this...

      $0.00
    • Siemens 3RU1146-4MB0 thermal overload relay
      Quick view

      Siemens

      3RU1146-4MB0

      Siemens 3RU1146-4MB0 class 10 thermal overload relay for direct mounting on size S3 contactors (3RT1044, 3RT1045, and 3RT1046), is adjustable from 80A to 100A and has phase loss protection. The manual or automatic reset feature on this Sirius...

      $0.00
    • Siemens 3RU2126-1DB0 thermal overload relay Siemens 3RU2126-1DB0 dimensions
      Quick view

      Siemens

      3RU2126-1DB0

       The Siemens 3RU2126-1DB0 overload relay is adjustable from 2.2 to 3.2 AMPS, has a manual or automatic reset option and mounts to any 3RT2 size 0 contactor from 9 to 38 AMPS.  This UL rated thermal overload relay comes with phase loss...

      MSRP: $86.00
      $55.46
      Add to Cart
    • Siemens 3RU2126-1EB1 thermal overload relay Siemens 3RU2126-1EB1 wiring diagram
      Quick view

      Siemens

      |

      sku: 3RU2126-1EB1

      3RU2126-1EB1

      Siemens Sirius 3RT2126-1EB1 3 pole IEC rated separate mount thermal overload relay that is adjustable from 2.8 to 4.0 AMPS. Unit has class 10 tripping (trips in under 10 seconds or less), screw terminals, Manual or Automatic reset, 1 N.O. and 1 N.C...

      MSRP: $104.00
      $61.10
      Add to Cart
    • Siemens 3RU2126-1HB1 thermal overload relay Siemens 3RU2126-1HB1 wiring diagram
      Quick view

      Siemens

      |

      sku: 3RU2126-1HB1

      3RU2126-1HB1

      Siemens Sirius 3RT2126-1HB1 3 pole IEC rated separate mount thermal overload relay that is adjustable from 5.5 to 8.0 AMPS. Unit has class 10 tripping (trips in under 10 seconds or less), screw terminals, Manual or Automatic reset, 1 N.O. and 1 N.C...

      MSRP: $104.00
      $61.10
      Add to Cart
    • Siemens 3RU2126-4AB1 thermal overload relay Siemens 3RU2126-4AB1 wiring diagram
      Quick view

      Siemens

      |

      sku: 3RU2126-4AB1

      3RU2126-4AB1

      Siemens Sirius 3RT2126-4AB1 3 pole IEC rated separate mount thermal overload relay that is adjustable from 11 to 16 AMPS. Unit has class 10 tripping (trips in under 10 seconds or less), screw terminals, Manual or Automatic reset, 1 N.O. and 1 N.C...

      MSRP: $104.00
      $61.10
      Add to Cart
    • Siemens 3RU2126-4CB1 thermal overload relay Siemens 3RU2126-4CB1 wiring diagram
      Quick view

      Siemens

      |

      sku: 3RU2126-4CB1

      3RU2126-4CB1

      Siemens Sirius 3RT2126-4CB1 3 pole IEC rated separate mount thermal overload relay that is adjustable from 17 to 22 AMPS. Unit has class 10 tripping (trips in under 10 seconds or less), screw terminals, Manual or Automatic reset, 1 N.O. and 1 N.C...

      MSRP: $104.00
      $61.10
      Add to Cart
    • Siemens 3RU2136-4RB0 thermal overload relay 3RU2136-4RB0 Side Dimensions
      Quick view

      Siemens

      |

      sku: 3RU2136-4RB0

      3RU2136-4RB0

      Siemens 3RU2136-4RB0 thermal overload relay for mounting on Sirius 3RT203 size S2 contactors (3RT2038) and is adjustable from 70A-80A. This Class 10 overload (trips in 10 seconds or less) has phase loss protection, manual or automatic reset and two...

      MSRP: $310.00
      $158.24
      Add to Cart
    • Siemens 3RU2146-4MB0 overload relay Siemens 3RU2146-4MB0 front dimensions
      Quick view

      Siemens

      |

      sku: 3RU2146-4MB0

      3RU2146-4MB0

      Siemens 3RU2146-4MB0 Class 10 thermal overload relay for mounting on new Sirius 3RT204 size S3 contactors (3RT2045, 3RT2046, and 3RT2047) and is adjustable from 80 to 100 AMPS.  This Siemens Sirius overload relay comes with 1 normally open and 1...

      MSRP: $290.00
      $154.90
      Add to Cart
    Compare Selected