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Overload Relays

With the introduction of overload relays in the mid-1900's, motor protection reached a new level. When a protective relay was added to a standard contactor, it provided a low-cost level of protection saving time and money on replacing the more expensive pieces of machinery that were being operated down stream of this new "starter".


Electronic overload relays come in many different forms and have evolved over the years. Originally there were bi-metal heaters, which were strips of metal that when heated to a certain temperature, would cause a "trip" and shut down power to the contactor and subsequently the motor being operated. This allowed for automatic protection of a motor in an over-amperage state. One heater was needed for each leg of the motor and these bi-metal heaters were used for many years.


Following the use of bi-metal heaters came the introduction of thermal overload relays. These provided greater flexibility in motor protection with phase loss (single phase sensitivity) tripping, different class trips (from 5 to 30 though 10 is the standard), manual or automatic reset and most importantly a wider AMP range per unit.  While bi-metal heaters had a small AMP range, sometimes 1 to 2 AMPS at most, thermal overloads could have AMP ranges ranging 20 to 30 AMP in the higher ratings.  This provides for great convenience and portability should an application change from 460 volt down to 230 volt.


The newest innovation in this category is the advent of electronic or solid state overload relays.  These relays offer every option imaginable from a 4:1 or even a 5:1 AMP adjustment ratio to class selection all in the same unit.  Larger units can have AMP ranges from 20-100 AMP, manual and automatic reset and trip class selections from 5 seconds up to 30 seconds. These electronic overload relays also are now self-powered and no longer require a separate power source for operation.

  • Eaton XTOE045CCS overload relay Eaton XTOE020CCS front dimensions

    Eaton XTOE045CCS

    Eaton XTOE045CCS electronic overload relay that is adjustable from 9 to 45 AMPS and mounts to any frame C contactor from 18 to 38 AMPS. This next generation solid state overload relay provides accurate and reliable motor protection with multiple class...

    MSRP: $217.00
    $90.68
    Add to Cart
  • Eaton XTOE005BCS overload relay Eaton XTOE005BCS front dimensions

    Eaton XTOE005BCS

    Eaton XTOE005BCS electronic overload relay that is adjustable from 1 to 5 AMPS and mounts to any frame B contactor from 7 to 15 AMPS. This next generation solid state overload relay provides accurate and reliable motor protection with multiple class...

    MSRP: $198.00
    $84.13
    Add to Cart
  • Eaton XTOE005CCS overload relay Eaton XTOE005CCS front dimensions

    Eaton XTOE005CCS

    Eaton XTOE005CCS electronic overload relay that is adjustable from 1 to 5 AMPS and mounts to any frame C contactor from 18 to 38 AMPS. This next generation solid state overload relay provides accurate and reliable motor protection with multiple class...

    MSRP: $217.00
    $90.68
    Add to Cart
  • Eaton XTOE020BCS overload relay Eaton XTOE005BCS front dimensions

    Eaton XTOE020BCS

    Eaton XTOE020BCS electronic overload relay that is adjustable from 4 to 20 AMPS and mounts to any frame B contactor from 7 to 15 AMPS. This next generation solid state overload relay provides accurate and reliable motor protection with multiple class...

    MSRP: $198.00
    $84.13
    Add to Cart
  • Eaton XTOE020CCS overload relay Eaton XTOE020CCS front dimensions

    Eaton XTOE020CCS

    Eaton XTOE020CCS electronic overload relay that is adjustable from 4 to 20 AMPS and mounts to any frame C contactor from 18 to 38 AMPS. This next generation solid state overload relay provides accurate and reliable motor protection with multiple class...

    MSRP: $217.00
    $90.68
    Add to Cart
  • Eaton XTOE045DCS overload relay Eaton XTOE045DCS front dimensions

    Eaton XTOE045DCS

    Eaton XTOE045DCS electronic overload relay that is adjustable from 9 to 45 AMPS and mounts to any frame D contactor from 40 to 65 AMPS. This next generation solid state overload relay provides accurate and reliable motor protection with multiple class...

    MSRP: $297.00
    $119.97
    Add to Cart
  • Eaton XTOE100DCS overload relay Eaton XTOE045DCS front dimensions

    Eaton XTOE100DCS

    Eaton XTOE100DCS electronic overload relay that is adjustable from 20 to 100 AMPS and mounts to any frame D contactor from 20 to 100 AMPS. This next generation solid state overload relay provides accurate and reliable motor protection with multiple class...

    MSRP: $364.00
    $151.93
    Add to Cart
  • Eaton XTOE1P6BCS overload relay Eaton XTOE1P6BCS front dimensions

    Eaton XTOE1P6BCS

    Eaton XTOE1P6BCS electronic overload relay that is adjustable from 0.33 to 1.6 AMPS and mounts to any frame B contactor from 7 to 15 AMPS. This next generation solid state overload relay provides accurate and reliable motor protection with multiple class...

    MSRP: $198.00
    $84.13
    Add to Cart
  • Eaton XTOE1P6CCS overload relay Eaton XTOE1P6CCS front dimensions

    Eaton XTOE1P6CCS

    Eaton XTOE1P6CCS electronic overload relay that is adjustable from 0.33 to 1.6 AMPS and mounts to any frame C contactor from 18 to 38 AMPS. This next generation solid state overload relay provides accurate and reliable motor protection with multiple...

    MSRP: $217.00
    $90.68
    Add to Cart