SIBA Fast-Acting Ceramic Fuses - 5x20mm Reliable and versatile SIBA fuses for a range of requirements and applications. Very high breaking capacity Good mechanical/vibration characteristics Ceramic cartridge bodies are sand filled Typical Applications include short-circuit protection of semiconductors such as thyristors, diodes and triacs. Note that with values of greater than 6.3A the use of open type fuseholders is recommended, to reduce the risk of nuisance tripping at or near full rated current.