GRL DNH1GM Series Fuse Switch Disconnector 800V AC 160A 250A 630A Use NH fuse link

 Fuse Switch Disconnector DNH1GM Series Technical Parameters

GRL DNH1GM Series Fuse Switch Disconnector: High-Performance AC Protection for 800V Systems

1. Introduction and Market Significance

In modern industrial and utility-scale power distribution, especially within the rapidly growing renewable energy sector (such as advanced solar PV installations and industrial power conditioning), the demand for reliable and high-capacity components operating at medium-high low voltage levels is essential. The GRL DNH1GM Series Fuse Switch Disconnector is specifically engineered to meet this critical need, offering a robust and flexible solution for circuit protection and isolation.

The DNH1GM Series is defined by its strong performance parameters: a nominal system voltage rating of 800V AC and a wide current range capability, supporting frame sizes for 160A, 250A, and 630A. This series utilizes the globally accepted NH fuse link standard, providing designers with the flexibility to select fuses appropriate for various load profiles and protection characteristics. By integrating the functionality of a manual disconnector with the rapid fault clearance of a fuse, the DNH1GM Series guarantees both operational safety and comprehensive equipment protection.

This detailed document explores the architecture, technical advantages, diverse applications, and installation considerations of the GRL DNH1GM Series, confirming its status as a premier choice for 800V AC system protection.

Product brief introduction

The DNH1GM series Fuse Switch Disconnector (hereinafter referred to as the “switch”) are applicable to rated insulation voltages of AC 1000V/AC 1250V, with a frequency of 50/60Hz and a working voltage of AC 800V. They are mainly used in power distribution circuits and motor circuits with high short-circuit currents, serving as power switches, disconnectors, and emergency switches, and for circuit protection. This switch is not intended for directly opening and closing individual motors. When the switch is replaced by an isolating knife instead of a fuse, this switch loses the function of overcurrent and short-circuit protection and only meets the requirements for circuit isolation as specified by this switch.

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2. Design Architecture and Core Features

The GRL DNH1GM Series is built upon a foundation of durability, safety, and operational efficiency, making it highly suitable for demanding industrial environments.

2.1. Optimized for 800V AC Systems

While many traditional fuse switches are optimized for 400V or 690V, the DNH1GM Series is specifically rated for 800V AC. This makes it ideal for specialized power systems that operate at this voltage level, such as the output stages of higher-power inverters, certain types of industrial furnaces, and dedicated power supply branches. The device’s robust insulation and optimized clearance/creepage distances ensure reliable long-term performance at this higher voltage.

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2.2. Robust 3-Pole Design (3S)

The 3-pole configuration is standard for three-phase AC power systems, ensuring simultaneous switching and protection across all three phases. The “3S” designation often implies a solid, secure switching mechanism designed for frequent, yet safe, operation under rated conditions. The contacts are typically fabricated from highly conductive, arc-resistant materials to ensure minimal power loss and long operational life, even after interrupting fault currents.

2.3. Optimization for NH000 Fuse Links

The choice to utilize the NH000 standard is strategic. NH (low-voltage high-rupturing capacity) fuses are known for their high breaking capacity and reliability. The compact size of the NH000 form factor allows the DNH1-160-3S to maintain a relatively small footprint, optimizing panel space without compromising protective capability.

2.2. Flexible Current Ratings (160A, 250A, 630A)

The DNH1GM Series is a platform solution that accommodates different frame sizes to cover substantial current demands:

• 160A Frame Size: Typically uses NH000 or NH00 fuse links, suitable for smaller distribution branches or specialized equipment lines.

• 250A Frame Size: Uses NH1 or similar compact fuse links, ideal for medium-power applications and main circuit protection in smaller panels.

• 630A Frame Size: Uses NH3 or other larger fuse links, designed for heavy-duty applications, main incoming feeders, and high-capacity switchboards.

This modularity allows engineers to standardize on the DNH1GM platform while customizing the current rating based on the specific application requirements.

2.3. Versatility with NH Fuse Links

The use of standard NH (low-voltage high-rupturing capacity) fuse links is a key feature. NH fuses are widely available and renowned for their exceptional breaking capacity (often exceeding 100kA), ensuring the safety of the entire electrical installation under severe short-circuit conditions. The design of the DNH1GM holders ensures secure, low-resistance contact with the fuse body across all compatible NH sizes.

2.4. Dual Functionality: Isolation and Protection

Like other GRL high-performance switch disconnectors, the DNH1GM provides essential dual functions:

• Circuit Protection: Achieved via the installed NH fuse, offering rapid fault interruption.

• Safe Isolation: A mechanically robust switch allows for guaranteed physical separation of the circuit, essential for maintenance and compliance with lockout/tagout procedures.

Application Environments and Industry Focus

The 800V AC rating and multiple current levels make the GRL DNH1GM Series a superior choice for several demanding sectors:

Renewable Energy Generation (Solar & Storage)

• Inverter Output Protection: Used on the AC side of centralized solar inverters and battery energy storage systems (BESS) where intermediate AC voltage levels around 800V are often utilized for efficiency before transformation.

• Feeder Protection: Providing essential protection for the AC feeder lines connecting power generation facilities to the main substation.

Heavy Industry and Manufacturing

• Large Motor Control Centers (MCCs): Protecting high-power motors and related switching gear operating at elevated industrial voltages.

• Rectifier/Inverter Circuits: Used within VFDs, rectifiers, and other power electronic devices common in manufacturing, where they require precise, high-speed fuse protection.

Power Distribution and Utilities

• Substation Auxiliary Circuits: Used in high-reliability applications where robust isolation and circuit protection are non-negotiable.

• Custom Switchboards: Ideal for bespoke switchgear and distribution boards where high power density and specific voltage requirements must be met.

Selective Coordination

The use of standard NH fuses facilitates selective coordination—the ability of a protective device closest to a fault to trip before devices upstream. By selecting the appropriate fuse sizes (e.g., using a smaller NH fuse in a 160A frame branch circuit and a larger NH fuse in the 630A main feeder), engineers can design systems that minimize outages and maximize operational uptime.

Installation and Operational Safety

Safety and ease of operation are paramount in the DNH1GM design.

DNH1 Fuse Switch Disconnector Wiring method

The GRL DNH1GM Series Fuse Switch Disconnector is a high-specification, essential component for any modern electrical system operating at 800V AC. Its platform approach, which seamlessly integrates 160A, 250A, and 630A frame sizes with standard NH fuse links, provides unmatched flexibility and high-capacity protection.

By choosing the DNH1GM Series, engineers and system operators are investing in a product that delivers safety, operational reliability, and performance across the most challenging power environments, ensuring long-term protection for critical assets.

DNH1 Fuse Switch Disconnector Product Showcase

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