Siemens SITOR 25A 3NE8015-1 Fuse | 690V 100kA

SIEMENS SITOR 25A FUSE 3NE8015-1

The Siemens SITOR 25A Fuse (3NE8015-1) is a special ultra-fast semiconductor protection device that is meant to protect thyristors, diodes, and IGBTs from the catastrophic effects of short circuits. This NH000 size fuse is made for the 690VAC range with a wonderful 100kA breaking capacity and is a staple in nautical motor controllers and frequency converters.

Technical Specifications

Applications

• Variable Frequency Drives (VFDs): Adapter for the inverter bridge in bow thrusters and winch motors.
• Soft Starters: Protect thyristors during severe load motor starts.
• DC Power Supplies : Protecting rectifiers in shipboard battery charging systems .
• UPS Systems: Providing clean power to support navigation and communication gadgets.
• Power Converters Key role in renewable energy integration (e.g., shaft generators and solar arrays).

Guidance From NDMarineTech:

1) The Cold Resistance Check: Before installing a new 3NE8015-1, always check the continuity with a high-quality multimeter. If you are replacing a blown fuse, inspect the fuse base for signs of carbon tracking or silver migration. Heat is the enemy—ensure your terminal connections are torqued to the manufacturer’s spec (usually 10-12 Nm for NH000 bases) to prevent nuisance tripping.

2) Ambient Temperature Derating: In a cramped, hot engine room cabinet, the 25A rating isn’t absolute. If your ambient temperature exceeds 40°C, apply a derating factor of approximately 0.8. Running this fuse at its limit in high heat will lead to premature aging of the element.