Why Choose the Mersen NH4AM50V400-8 NH Fuse-Link?
The Mersen NH4AM50V400-8 is a heavy-duty DIN NH aM fuse-link developed specifically for the short-circuit protection of high-power industrial motor circuits. Manufactured by Mersen, this NH size 4 fuse-link delivers strong current-limiting performance whilst allowing normal motor starting currents to pass without unnecessary fuse operation.
As part of the proven Mersen NH aM 500 V fuse-link series, the NH4AM50V400-8 features a robust ceramic body, silver-plated copper blade contacts, live gripping lugs and a top-mounted indication system. Its large NH4 construction is suited to demanding motor control centres, industrial switchboards and machinery installations carrying substantial operating currents.
With a rated current of 400 A, a rated operating voltage of 500 V AC and a high 120 kA AC breaking capacity, the NH4AM50V400-8 provides dependable protection against severe short-circuit currents. As an aM fuse-link, it must be coordinated with a suitable overload relay or motor protection device to provide complete motor circuit protection.
Key Advantages
- Purpose-designed aM fuse-link for heavy-duty motor circuit protection.
- 400 A rated current for high-power industrial motor applications.
- 500 V AC rated voltage for low-voltage power systems.
- High 120 kA AC breaking capacity for reliable fault interruption.
- Strong current-limiting performance helps protect contactors, starters and cables.
- Top indicator enables quick identification of an operated fuse-link.
Key Features
- Mersen NH aM 500 V fuse-link series.
- DIN NH size 4 construction.
- 400 A rated current.
- 500 V AC rated voltage.
- aM partial-range characteristic for motor circuit protection.
- Live gripping lugs for use with a suitable LV HRC fuse puller.
- Top-mounted fuse status indicator.
- Ceramic body with silver-plated copper blade contacts.
Reliable Motor Circuit Protection
aM fuse-links are partial-range protective devices designed specifically for motor circuits. They interrupt currents from approximately 6.3 times their rated current up to their maximum breaking capacity, whilst tolerating the temporary inrush currents produced during normal motor starting.
The NH4AM50V400-8 provides short-circuit protection only and must be combined with a thermal overload relay, motor protection circuit breaker or another suitable overload device. This coordinated arrangement provides effective protection for motors, contactors, cables and associated switching equipment.
Typical Applications
- Heavy-duty industrial motor control centres.
- Large direct-on-line and reversing motor starters.
- Industrial switchboards and power distribution panels.
- Pumps, fans, compressors and conveyor motor circuits.
- Manufacturing and processing machinery.
- OEM automation and machine-building applications.
