The DNH50 series DC Switch Disconnector is suitable for power systems with a rated voltage of DC 1500V and below, or AC 690V and below for 50/60Hz, and a rated current of 50A and below.
The product can be used for infrequent switching on and off to isolate and disconnect circuits. lt can be widely used in many industries such as construction,telecommunications, metallurgy, and solar photovoltaic systems.
1. Rotating double break point technology
Disperse arc when disconnecting, improve making capacity and breaking capacity, and improve product electrical life；
2. Knife blade contact structure
Connection is reliable,which improves short-time withstand current.
3. Magnetic Blowout Technology
Permanent magnets are set between the moving and static contacts, and magnetic blow-out arc extinguishing technology is adopted.
When arc comes into being between the moving and static contacts, it can be quickly stretched and extinguished,
4. Zero arc design
Zero flash over for whole series, smaller installation space, and safer to use;
5. High-temperature resistant housing
Made of UL94V0 grade flame-retardant material, preventing fire hazards during system faults.
6. UV-Resistant handle
Made from materials that comply with UL746C standards for long-term outdoor use.
7. Modular assembly structure
Allows flexible selection of pole numbers.
8. Easy Installation
Easy to install.Wiring and operation tools are not in the same direction, which improves the efficiency of tool use, reduces the space occupied by the product, and facilitates product replacement and maintenance.
1. Enhanced safety
The product uses advanced technologies to ensure safe operation and disconnection.
2. Long service life
Designed for durability with high mechanical and electrical life cycles.
3. Versatile applications
Suitable for various industries and power systems.
4. Compact design
The zero arc design minimizes installation space requirements.
1. Check whether the switch is in good condition and flexible operation before installation. The switch should be installed vertically.
Before installation, check whether the content of the nameplate meets the requirements. The confirmation switch should be in the off state.
Pull the switch operation handle, the arrow on the handle points to “0”, the switch is off, the arrow points to “I”, the switch is off.
2. The wiring terminal and wiring bare bus on the switch should be wrapped with insulation to prevent short circuit between phases.
3. If the extension shaft and the handle hole do not match, please do not pull the extension shaft, so as not to damage the internal parts, be sure to adjust the switch position to make the extension shaft and the handle hole match.
4. The switch should be maintained every six months. If the rotating part is not flexible, apply grease (MP-3 grease is recommended).
Check whether fasteners are loose. And for different situations to be repaired, if the damage is serious, stop the use.
1、Operating Temperature/Storage Temperature:
The normal operating ambient temperature range is -40℃ to +75℃.
If the ambient temperature exceeds +75℃ or falls below -40℃, users should consult with the manufacturer.
Storage temperature: -50℃ to +85℃.
2、Protection Level
Product protection level IP20, handle protection level IP66.
3、Relative Humidity
The relative humidity of the atmosphere should not exceed 50% at +40℃.
At lower temperatures, higher relative humidity is allowed. For example, at 20℃, the relative humidity can reach 90%.
Users should take special protective measures against occasional condensation due to temperature changes.
As solar farms expand globally to meet renewable energy targets, the role of DC isolator switches becomes increasingly critical. These components are the unsung heroes of photovoltaic (PV) systems, ensuring safe disconnection of high-voltage DC circuits during maintenance, emergencies, or system upgrades. However, installing DC isolators in large-scale solar farms poses unique challenges due to the scale, environmental demands, and stringent safety regulations.
Whether you’re an engineer, project developer, or installer, understanding these top five considerations will help you select and deploy DC isolators that enhance system reliability, comply with international standards, and minimize operational risks.
Solar farms operate at extremely high DC voltages (up to 1,500V) to reduce energy losses over long distances. Choosing isolators with insufficient voltage or current ratings can lead to catastrophic failures, including arcing, overheating, or even fires.
Calculate Maximum System Voltage: Account for temperature coefficients and “open-circuit voltage” (Voc) of solar panels, which can spike in cold conditions. For instance, a 1,000V system might temporarily exceed 1,200V in sub-zero climates.
Select Isolators with a Safety Margin: Opt for isolators rated 20–30% above your system’s maximum voltage. For example, GRL Electric’s DNH50 Series handles up to 1,500V DC, making it ideal for utility-scale projects.
Consider Future Expansion: Modular isolators allow scalability if the solar farm expands or integrates battery storage.
Example: A 50MW solar farm in Arizona faced isolator failures due to voltage surges during summer peaks. Upgrading to 1,500V-rated isolators with enhanced thermal stability resolved the issue.
Unlike AC systems, DC circuits lack natural current zero-crossing points, making arc interruption challenging. Persistent arcing during disconnection can damage equipment and endanger personnel.
Solutions:
Magnetic Blowout Designs: These use magnetic fields to stretch and cool arcs, extinguishing them within milliseconds. Brands like GRL integrate this technology into their DNH50 Series isolators.
Widened Contact Gaps: Increasing the distance between contacts reduces the risk of arc re-ignition.
Case Study: A solar farm in Germany reduced maintenance downtime by 40% after switching to isolators with magnetic blowout technology, as technicians could safely disconnect circuits without waiting for arcs to dissipate.
Solar farms are exposed to harsh conditions—UV radiation, temperature extremes (-40℃ to +85℃), dust, and moisture. Substandard isolators degrade quickly, leading to corrosion, insulation failures, or water ingress.
Partnering with Experts for Long-Term Success
Selecting the right DC isolators for solar farms is a balancing act between technical specifications, environmental resilience, and regulatory compliance. Cutting corners on quality can lead to costly downtime, safety incidents, or failed inspections.
Brands like GRL stand out by offering isolators engineered for utility-scale solar projects. Their DNH50 Series combine ultra-high voltage ratings (1500VDC), robust arc suppression, and global certifications, making them a go-to choice for developers worldwide.
For solar farm operators, investing in premium DC isolators(DC switch disconnector) isn’t just about compliance—it’s about safeguarding assets, ensuring operational continuity, and supporting the global transition to clean energy.
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GRL Electric Co., Ltd. is one of the leading companies in the Middle And High End market of low-voltage electric in China
