Fuse cut-out with striker VVT-D3 12kV/25A 004232010

Reliable medium voltage protection

VVT-D3 12kV/25A fuse link is an element designed to protect medium voltage (MV) electrical and power equipment against the effects of short circuits and overloads. It finds application in securing wires, cables, transformers, motors, and capacitor banks. The design of the fuse link, taking into account the thermal trigger, ensures protection not only against sudden current surges but also against gradual temperature increases, which is particularly important in specific operating conditions.

Construction and operating principle

The VVT-D3 fuse link is equipped with a thermal trigger, which activates a striker with a force of 80N when the fuse body reaches a temperature of approximately 120°C. This mechanism operates independently of the heat source, guaranteeing reliable operation even in the event of prolonged overloads. The striker signals the operation of the fuse link and enables the activation of the tripping mechanism of power fuses. Additionally, the use of a high-strength ceramic tube and contacts galvanically protected with nickel-plated (Ni) electrolytic copper caps ensures durability and corrosion resistance. The fuse element made of silver guarantees effective conduction of the rated current of 25A at a voltage of 6/12kV and a frequency of 50/60Hz.

Key features and benefits

• High short-circuit breaking capacity: up to 63 kA – ensures effective protection of the installation even with high short-circuit currents.
• Thermal trigger: protects against thermal overloads and uncontrolled temperature increases, extending the life of equipment.
• Reliable sealing system: protects against moisture and corrosion, ensuring stable operation in various environmental conditions.
• Fast tripping indication: thanks to the 80N striker, it is easy to identify a blown fuse link and take appropriate repair actions.
• Easy replacement: improved contact cap facilitates and speeds up the process of replacing the fuse link during maintenance or failure.
• Compliance with standards: VV fuse links have technical reports from KEMA Labs tests, confirming their quality and safety.
• Wide application: ideal for SF6 gas switchgear due to the characteristics of the thermal trigger.

It is important to remember the minimum breaking current I₃ of 3A – below this value, the fuse link may not operate correctly during overloads. Cold resistance Rc is 33 mΩ and power loss Pn is 28W. The pre-arc integral I₂t min is 700 A²s and the maximum I₂t max is as high as 10000 A²s, which proves the high energy that the device can withstand during a short circuit.