The World Depends on Sensors and Controls
Automotive Breakers:
    Circuit Breaker
ATC Footprint:
EXT 500 Type 1
    Circuit Breaker
ATM Footprint:
EXT 300 series
    Circuit Breaker
ATC Footprint:
EXT 200 Type 2
    Circuit Breaker
MAXI Footprint:
Maxi Breaker® series

Site Updated February 16, 2018

* * * Sensata > Products > Circuit Breakers > Automotive > EXT300

Automotive Circuit Breakers
EXT 300 Series

Overview Data Sheet (PDF)  

SAE Type 1 (cycling) and Type 2 (non-cycling) device
Metal Encased
Multiple bimetallic resistivities available

Compact design allows for integration into many areas of the vehicle
Protected from abuse and contamination of the contact surface
Meets longer life cycle requirements
Low and stable series resistance

Sensata Technologies' EXT 300 Mini Footprint Series of circuit breakers are designed for wiring harness protection in 12 Volt DC automotive applications. The EXT 300 is an ideal protection device to guard against momentary overloads. This device is especially designed for use in fuse blocks, where horizontal space is limited, but where there is enough vertical height to accommodate a relay. The EXT 300 can be mounted in a mini-fuse location. This bimetallic device is sensitive to both over-current and over-temperature fault conditions.

Sensata Technologies is an ISO and QS registered company providing world class quality products.

General Envelope Dimensions, mm (inches)
Nominal dimensions provided for reference only.


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Thermal Circuit Breakers

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Peerless Electronics Inc.
700 Hicksville Road
Suite 100
Bethpage NY 11714
Phone: 516-594-3500
Phone: 800-285-2121
Fax: 516-593-2179

Trip Curve

Diagram: Approximate effect of ambient temperature on ultimate trip
General Specifications
Nominal Operating Voltage
12 Volts DC
Typical voltage drop at operating current
200 mV max
Current Rating
5 to 30 amps @ 25ºC (in 5 amp increments)
Typical ambient temperature range
-40ºC to 85ºC

These curves are to be used only as a guide in selecting a protector for a particular application. Factors such as distance from the heat source and the method of mounting should be considered in selecting a protector. Final trip times are dependent upon terminal configuration and mounting in the application.

All Sensata Circuit Breakers do not contain any hazardous materials and are 100% in compliance with the Substance of Concern (SoC), ELV and RoHS directives.

The World Depends on Sensors and Controls
The World Depends on Sensors and Controls