Ferraz Shawmut is involved in the medium voltage protection from many years. The expertise is centered on the protection of the MV/LV transformer in the power distribution networks with solutions encompassing medium voltage Limitor® fuses for overhead lines protection, oil-tight medium voltage fuses fitting the transformer tank and fault indicators especially the Nortroll® products. Our medium voltage solutions concern also the industrial field with both North-American and European (DIN) standard medium-voltage motor protection fuses. The offering covers also the protection of potential transformers and medium voltage capacitors.
General Purpose current-limiting fuses are designed to interrupt the high-fault currents and also the low-fault currents down to approximately 1.6 times their continuous current rating. This fuse is defined in the IEEE Std C37.40 -1993 (3.1.57) as "A fuse capable of interrupting all currents from the rated interrupting current down to the current that causes melting of the fusible element in no less than one hour." These fuses can be used outdoors without any protecting enclosure.
Rated voltage 12, 24, 36 and 38.5 kV
Rated current 630 A and 1250 A
Switch-fuse combinations are used for operational medium voltage-side on and off switching of distribution transformers in secondary substations. They additionally have the task of protecting these transformers against the impact of internal and external faults.
These combinations comprise a functional unit of switch disconnectors and back-up fuses.
By means of the fuses the breaking capacity of the combination is extended beyond that of a simple switch disconnector up to the rated short-circuit breaking current.
The high-voltage high breaking capacity fuse, according to statistics of the VDN (German Association of Electricity Network Operators) is rated as reliable transformer protection. The h.v.h.b.c. fuse in combination with a switch disconnector provides a simple solution which is very economical to procure and run.
This provides a clear-cut advantage over a circuit breaker with the associated current transformers and overcurrent time protection.
Besides this, the h.v.h.b.c. fuse has a current limiting effect when short-circuits occur and reliably interrupts the fault current of the first half cycle.
These properties are advantageous for the dimensional design of the network.
see the results for the following category
