Power Fuse

Power Fuse is a generally accepted means to protect power transformers in distribution substations. The main purpose of the Power fuse is to provide a permanent fault interruption. Fuse is an economical alternative to circuit switcher or circuit breaker protection.

Fuse Fuse protection is usually limited to the voltage of 34.5 kv to the per kv, but has been used to protect the and 138 kv transformers. In order to provide the maximum protection margin, the lowest possible fuse rating must be used. The advantage of a closed fuse is that the fuse unit provides backup protection for some two faults. For common triangular connection transformers, a fuse ratio of 1.0 will provide backup protection for relative faults, as low as 230% of the secondary full load rating. The fuse ratio is defined as the ratio of the fuse rating to the full load current rating of the transformer.