Stackpole's flame proof SP3A axial leaded wirewound series is designed for robust surge handling and fail safe fusing. Unlike other metal film fusible resistors, the SP3A is rated at 3 watts at 70C and can withstand hundreds of 3KV pulses of 50 microseconds or less without fail or significant resistance shift. Yet under continuous overload, the SP3A fuses very quickly without flame or significant self-heating.
Compared to other UL1412 approved fusible wirewound resistors which sacrifice surge handling to ensure a reliable fusing action, Stackpole's unique materials and processes focus the energy of the continuous overload to quickly open the resistance wire while retaining the pulse handling normally provided by the wirewound element.
The SP3A UL recognized part (file no. E344795) is available in resistance values from 10 ohms up to 100 ohms. Other non-UL recognized values and sizes maybe available. Contact the factory for more information. Pricing for the SP3A ranges from $0.18 to $0.25 each in full reel quantities. Contact Stackpole or one of our franchised distributors for volume pricing. Samples are available via online distribution.
Stackpole Electronics Inc.
Part Number: SP3A