NH fuse knife switch Eti-Polam 004941213 — NH1 250A, ZI type

Eti-Polam NH fuse knife switch 004941213 (NH1 250A, ZI type) is a replaceable NH1-size fuse holder intended for low-voltage distribution and protection systems. It is designed to accept NH-format cartridge fuses rated up to 250 A and provides a robust knife contact mechanism for secure insertion, reliable electrical connection and manual disconnection of NH fuses. The construction suits installation in switchgear, distribution panels and industrial protection setups where NH cartridge fuses are the selected protection method.

Advantages

The NH1 knife switch offers a compact footprint and standardized NH1 dimensions for compatibility with common NH cartridge fuses. Its knife contact design ensures stable conductivity and straightforward manual operation for inserting and removing fuses. The replaceable holder format simplifies maintenance and replacement without extensive rewiring, and the ZI type provides a defined contact geometry for repeatable connections.

Suitable for

• Low-voltage switchgear and distribution boards using NH cartridge fuses
• Industrial panels requiring 250 A overcurrent protection
• Application areas where a manual knife-type fuse holder is preferred for serviceability
• Retrofit or replacement of existing NH1-size holders in distribution installations

When it may not be suitable

This NH1 fuse knife switch is not intended for use with fuse cartridges of different NH sizes or ratings above 250 A. It is a manual, replaceable holder and does not include automatic switching or remote operation features; systems that require motorised operation or remote trip/status signalling may require a different product. Environments demanding specific ingress protection, corrosion resistance or non-standard materials should be checked against the holder's construction details before installation.

Key specifications

• Rated current: 250 A
• Fuse format compatibility: NH1 cartridge fuses
• Contact type: knife (manual insertion/removal)
• Intended use: low-voltage distribution and protection systems
• Mounting: panel/switchgear-replaceable holder format

How to use

Mount the replaceable NH1 holder into the designated slot inside the switchgear or distribution panel using compatible fixing points. Ensure power is isolated before inserting or removing NH cartridges. Insert the NH cartridge fuse into the holder so the cartridge engages the knife contacts fully; verify secure mechanical seating and firm electrical contact. For removal, isolate the circuit and withdraw the cartridge by operating the knife contact mechanism. Follow local electrical safety regulations and the switchgear manufacturer's instructions when performing installation, replacement or maintenance.

What to consider before purchase

• Confirm compatibility with NH1-sized cartridge fuses and a 250 A rating.
• Verify physical dimensions and mounting method match your switchgear or panel.
• Ensure the manual knife-type operation meets your service and safety requirements.
• Check environmental and mechanical requirements (temperature, humidity, vibration) for your installation.

Usage recommendations

Use in systems with clearly defined isolation procedures and train personnel on safe fuse handling. Regularly inspect contacts for signs of wear, overheating or corrosion and replace the holder if contact integrity is compromised.