Fuse cut-out with striker VVT-D3 12kV/31,5A 004232011

Medium Voltage VV Fuses – Reliable Installation Protection

VV fuses are a proven protection element in medium voltage networks. Designed to protect electrical and power equipment MV (cables, conductors, transformers, motors, capacitor banks) against the effects of short circuits and overloads. Particularly the VVT-D3 model, thanks to the built-in thermal trigger, provides additional protection against uncontrolled temperature increases.

Construction and operating principle

VVT-D3 fuses are equipped with a thermal trigger that activates the striker with a force of 80N when the fuse body reaches a temperature of approximately 120°C – regardless of the cause of the temperature increase. This design is particularly recommended for use in switchgear with SF6 gas. High moisture resistance thanks to a reliable sealing system and a high-strength ceramic tube guarantee long-lasting and trouble-free operation. Galvanically protected contacts and caps made of electrolytic copper coated with nickel (Ni) ensure optimal electrical connection. An improved contact cap facilitates fuse replacement. The fuse element is made of silver, which affects the stability and effectiveness of the operation.

Parameters and application

The VVT-D3 12kV/31.5A fuse is characterized by a rated breaking capacity of 63 kA. It is designed to operate in AC networks with a voltage of 6/12 kV and a frequency of 50/60 Hz. The cold resistance is 29 mΩ, and the power loss is 38 W. The minimum pre-arcing integral I²t min is 1400 A²s, and the maximum breaking integral I²t max is 15000 A²s. The housing diameter is 53 mm, and the length (without the contact cap) is 292 mm. The weight of a single fuse is 1.6 kg. The minimum breaking current I₃ is 110 A.

It is worth remembering that a base version with a microswitch signaling the fuse operation (VVP…BSW) is also available.