In loop type fire alarm system, it often occurs that partial short circuit of loop affects the whole system. DC-9504E Loop Isolator can isolate the shorted circuit from the complete loop to ensure normal operation of other parts and locate the isolated part. The isolator is applicable to all kinds of loop fire alarm systems, suitable for Class A and Class B. As a base type, the isolator can be used to replace a common base, to save installation and cabling.