Device Helps Provide Resettable Circuit Protection For Automotive Wire Harnesses

Unlike Type II bimetal circuit breakers – which typically cycle several times before latching – the PolySwitch BD280 device features a no-moving parts design with a resistance switching action that latches immediately following an overcurrent tripping condition that causes the resistance of the device to increase to a high value. Such latching occurs even at lower battery voltage and low environmental temperatures. Since the device has no contacts to arc, erode or weld together, the resettable PolySwitch device offers longer life than bimetal breakers and can provide more reliable performance.

The PolySwitch BD280 device is a constant wattage device, providing virtually constant power consumption across a voltage range of 4V to 14V. The device’s low power dissipation and flatter thermal derating result in less thermal crosstalk between devices than a Type II bimetal circuit breaker. Rated for operating temperatures between - 40ºC and +125ºC, the PolySwitch BD280 device passes more current at higher temperatures than bimetal circuit breakers and is suitable for harsh underhood applications.

The solid-state construction of the PolySwitch BD280 series provides high resistance to shock, vibration and rough handling. The bright color-coded housing and rated current value printed on the top of the device make replacement of automotive fuses and bimetal breakers easy, and help prevent installation errors. The device also incorporates two exposed probe points to facilitate inspection and faultfinding.

The PolySwitch BD280 device is used to help provide resettable overcurrent protection for power window, power seat, and power outlet circuits. Available in current ratings of 10A, 15A, 20A, 25A and 30A, the devices meet all applicable SAE and ISO standards.