Circa Telecom 4B1FS-240 Solid State 240V Fuse for Analog or Digital Lines (w/ self resetting current limiter)

Reference#: 68067
Item#: CR-4B1FS-240


This is a premium series 5 PIN solid state protector module that is designed to provide superior transient and power fault protection for most standard telephone line applications. These solid state modules are suited to applications that require the protection of sensitive telephone equipment due to their nanosecond reaction time. The characteristics of the solid state protector are far superior to gas tube technology in speed and are virtually immune to overshoot, aging and failure due to repeated tripping. 

The 4 - Series features PTC (positive temperature coefficient) technology. These optional self-resetting current limiters provide effective protection from 'sneak current' faults. The PTC is vastly superior to the heat coil solution, which requires that the module be replaced after each 'sneak current' event.


- Nanosecond response time
- Longer life span than conventional gas tube and
- External fail safe mechanism that permanently carbon arrestors grounds the module under sustained high current conditions
- Reduced 'pass through' of dangerous transients
- Integrated Test Points
- Fewer service calls
- UL & cUL listed
- Documented safe performance
- Designed to meet or exceed Telcordia standards