Frequently Asked Questions

Wenzhou Longqi New Energy Technology Co., Ltd. (CNLONQ) was founded in 2010 and is headquartered in the Shangyou Industrial Zone, Liushi, Yueqing, Wenzhou, Zhejiang Province, China (Yueqing is known as the “Electrical Appliance Capital of China”). As a specialized custom manufacturer of photovoltaic protection system equipment, the company integrates R&D, design, production, sales, installation, and after-sales service.

• National High-Tech Enterprise
• Charitable Enterprise / Integrity Management Model Enterprise
• No. 1 in Sales of PV Combiner Boxes on Amazon in North America and Europe

CNLONQ was founded in 2010 and has since developed through the following stages:

• 2010-2019: Building Technical Expertise
• 2020: CNLONQ was officially incorporated
• 2021-2023: Product and Certification Breakthroughs
• 2024-2025: Global PV Solutions Partner

L — Connection

We are committed to connecting people with clean energy and building a sunny bridge to the future.

O — Optimization

We continuously optimize our product designs and production processes to enhance energy efficiency, safety, and user experience.

N — Network

We advocate for mutually beneficial partnerships and build an open global network of collaboration.

Q — Quality

Quality is our lifeline.

CNLONQ operates a total of 13 production lines, covering the entire manufacturing process—from combiner boxes (5 production lines), MCBs/MCCBs (2 production lines), DC smart monitoring (1 production line), and isolating switches (1 production line), to various types of protective devices (1 production line each for SPDs, fuses, PV connectors, and OUPAs).

The range includes solar DC combiner boxes, AC combiner boxes, AC/DC combiner boxes, battery protection boxes, and hybrid inverter & power distribution cabinets.

CNLONQ PV combiner boxes have obtained TÜV, CE, UKCA, CB, RoHS, and ISO certifications and are manufactured and developed in compliance with IEC, UL, and GB standards.

The PV combiner box series shown are rated IP65/66/68. The relevant product descriptions also highlight their waterproof, dust-resistant, and outdoor-use characteristics.

Choose based on your system type (DC or AC side), string input count (e.g., 4-in-1-out, 6-in-2-out), rated system voltage/current (typically 1000V or 1500V DC), enclosure IP rating (IP65+ for outdoor use), and whether smart monitoring or specific protection features (SPD, fuses) are needed. You can also contact us for assistance in selecting the right model (sales@cnlonq.com).

Yes. CNLONQ provides flexible OEM/ODM customization services. We tailor complete PV distribution and combiner solutions based on your specific system electrical parameters, component configurations, IP ratings, and enclosure requirements.

CNLONQ offers circuit breakers (MCB), isolator switches (QS), molded-case circuit breakers (MCCB), surge protectors (SPD), fuses, and DC smart monitoring.

• DC MCB (Miniature Circuit Breaker) Provides overload and short-circuit protection for lower-current circuits (typically up to 63A/125A), widely used for individual PV strings.
• DC MCCB (Molded Case Circuit Breaker) Handles higher currents (up to 800A+) and higher breaking capacities for major PV busbars, battery banks, and total output protection.
• DC Isolator (Disconnect Switch) A manually operated switch designed solely for circuit disconnection and physical safety isolation during maintenance; it has no automatic overcurrent or short-circuit protection.

The rated voltage must exceed the maximum open-circuit voltage (Voc) of your PV string at the lowest expected ambient temperature. Residential and small commercial setups usually use 500/1000V DC, while large utility-scale systems require 1500V DC.

Following standard solar codes (like NEC / IEC), calculate In ≥ 1.25 × Isc (short-circuit current) to account for continuous load, or up to 1.56 × Isc for long-term irradiation and temperature safety margins.

It defines the maximum fault current a breaker can safely interrupt without rupture, arcing, or contact welding. Ensure the breaker's Icu is higher than the prospective short-circuit current of the connected battery bank or PV array.

CNLONQ offers AC circuit breakers, surge protectors, ID, RCCBs, RCBOs, ATS, MTS, OUPA, LW, and AC smart monitoring.

An RCCB only detects and protects against earth leakage (residual current) and requires an MCB for overcurrent protection. An RCBO combines both functions into one unit, protecting against earth leakage, overload, and short circuits.

ATS (Automatic Transfer Switch) automatically switches power between the grid and backup/generator power when an outage occurs. MTS (Manual Transfer Switch) requires manual operation to switch sources.

Grid voltage can fluctuate or lose phases. An OUPA automatically disconnects the solar inverter or critical loads when voltage/phase abnormalities occur and self-reconnects when the grid returns to normal, preventing inverter damage.

Use 2P (1P+N or 2P) for single-phase AC systems (110V/120V/220V/240V) and use 3P or 4P (3P+N) for three-phase commercial/industrial grid connections (380V/400V/480V) depending on whether the neutral line requires isolation.

CNLONQ offers plastic waterproof junction boxes ranging from 2-way to 32-way, as well as metal (cold-rolled steel/201/304/316) waterproof boxes that can be customized to any number of ways. Available IP ratings include IP65, IP66, and IP68.

• IP65 Protects against low-pressure water jets and rainwater, ideal for standard outdoor setups.
• IP66 Protects against powerful high-pressure water jets and heavy storms.
• IP68 Fully sealed and dustproof, suitable for extreme weather conditions or offshore solar power applications.

• Plastic (ABS/PC) Lightweight, non-conductive, highly corrosion-resistant, and cost-effective for residential/rooftop setups.
• Metal (Steel/SS304/SS316) Offers superior mechanical impact strength (high IK rating) and excels in heavy industrial or corrosive coastal environments.

Yes. Our outdoor plastic enclosures are formulated with UV-stabilized materials and flame-retardant additives, ensuring long-term durability without brittleness or degradation under direct sunlight.

Yes. We offer full customization for pre-drilled holes, molded knockouts, and pre-assembled cable glands (PG/M threads) or MC4 solar connectors to streamline your on-site wiring.

CNLONQ offers standard MC4-compatible DC connectors, PG connectors, Y-branch and T-branch multi-way parallel connectors, inline fuse/diode connectors, and panel-mount bulkheads.

Rated voltage: 1000 V DC / 1500 V DC; rated current: 30 A to 50 A, depending on the internal pin and cable size, and fully compatible with high-power PV modules.

Compatible cable sizes: Standard 2.5 mm², 4 mm², 6 mm², and 10 mm² (14 / 12 / 10 / 8 AWG); PG connectors accommodate any cable size.

Yes. Constructed with UV-stabilized, UL94-V0 flame-retardant PPO or PC material and durable silicone seals, ensuring IP67/IP68 waterproof protection in extreme outdoor weather.

Dedicated tools ensure correct terminal crimping with ultra-low contact resistance (<0.5 mΩ) to prevent overheating and fire risks, while disconnect wrenches release safety locks without damaging the housing.

CNLONQ provides a turnkey solution, with the following typical process:

• Samples & Prototype Units Typically dispatched within 3 to 7 business days (standard off-the-shelf components usually ship within 48 hours).
• Standard Batch Orders Production takes approximately 10 to 15 business days following order confirmation and deposit payment.
• Custom OEM/ODM Orders Usually 20 to 30 business days, depending on custom tooling, specific enclosure hole drilling, pre-wiring complexity, or bespoke labeling.
• International Transit Time (Reference):
• Express Air Freight (DHL / FedEx / UPS) 3–7 business days (ideal for urgent samples).
• Standard Air Cargo 7–12 business days.
• Ocean Freight (FCL / LCL) 20–40 days depending on the destination port (Southeast Asia: ~10–15 days; Europe & North America: ~25–35 days).

• Direct Factory Pricing Tiered manufacturer rates with strict regional price protection to maximize profit.
• Full Product Range One-stop certified (CE, TÜV, IEC, RoHS) DC/AC combiner boxes, switches, breakers, SPDs, and enclosures.
• Free Training Online or on-site technical coaching and market insights to drive sales growth.
• Dedicated Engineering 1-on-1 technical support for project sizing, bidding, schematics, and OEM/ODM solutions.
• Local Leads & Marketing Regional sales inquiries, high-resolution media kits, and exhibition support.
• Priority Service & Warranty Dedicated account management, solid warranties, and fast replacement response.

CNLONQ offers a standard 18-month warranty on its solar protection components and combiner box solutions; selected product lines carry a 1- or 2-year term. Extended warranty options and customized after-sales service terms can also be arranged for project-specific contracts and authorized distributors.

• Power-Off & Safety Isolation Always isolate and de-energize both DC and AC power sources (turn off upstream isolators/breakers) before opening enclosures or conducting any cleaning or maintenance work.
• External Enclosure Cleaning Wipe the outside surfaces and heat sinks using a clean, soft cloth dampened with mild soapy water or fresh water to remove dust, sand, and salt deposits. Never use high-pressure sprayers or corrosive chemical solvents.
• Internal Dust & Debris Removal Open the cabinet doors and use a dry, low-pressure compressed air gun or an anti-static brush to remove accumulated internal dust, insect residue, or foreign particles.
• Terminal & Cable Inspection Periodically inspect internal terminals, busbars, and wiring screws for signs of loosening, thermal discoloration, or oxidation; re-torque screws to specified manufacturer values using an insulated torque screwdriver.
• Seal & Ingress Integrity Check Examine waterproof rubber gaskets, door seals, and cable glands (PG/M threads, MC4 plugs) to ensure they remain intact, pliable, and free from cracks or UV degradation.
• Surge & Protection Indicator Status Regularly check visual indicators on SPDs (replace cartridges if the window turns red/orange) and verify that fuse-links and circuit breakers operate smoothly.

• Shipping Methods Ocean freight (FCL/LCL for bulk orders), air freight/express (for samples and urgent orders), and railway freight (China-Europe Railway).
• Trade Terms EXW, FOB, CIF, CFR, and DDP/DDU (door-to-door with customs clearance available).
• Packaging Export-grade cartons with shockproof pearl cotton and standard pallets/wooden crates.
• Coverage Global export, primarily covering Europe, Latin America, Southeast Asia, the Middle East, Australia, and Africa.

Installation Time:

• Pre-wired Combiner Boxes & Enclosures Typically 30 to 60 minutes per unit, as internal breakers, SPDs, and busbars are pre-assembled—requiring only wall mounting and external cable terminations (MC4 or cable glands).
• Large Distribution Cabinets / Commercial Systems: Usually 2 to 4 hours, depending on cable routing complexity, ground grid connection, and system commissioning.
• Installer Requirements:
• Yes, professional installation is strongly recommended. High-voltage DC (up to 1000V/1500V) and AC circuits present serious risks of electric shock and arcing. Installation must be conducted or supervised by a licensed electrician or certified PV installer in accordance with local electrical regulations and grid connection standards.

• Ambient Temperature & Humidity Operate within the recommended range of -25°C to +60°C and relative humidity below 95% (non-condensing) to avoid thermal derating or condensation.
• Sunlight & Ventilation Mount in a well-ventilated, shaded location (under PV modules, eaves, or an awning); avoid direct solar irradiance to reduce internal overheating.
• Environmental Hazards Do not install in explosive, flammable gas atmospheres, or areas with corrosive chemical fumes; coastal installations require enclosures with anti-salt-spray/UV ratings (IP65+ / SS304/SS316).
• Mounting Orientation & Clearance Install vertically on a sturdy, fireproof wall or bracket (tilt angle within ±15°); maintain at least 300–500 mm of clearance around the box for airflow and maintenance access.
• Water & Ingress Safety Avoid low-lying depressions or flood-prone ground areas; ensure cable entry points face downward with properly sealed cable glands/MC4 connectors.

• Sample & Prototype Verification 1 to 5 units (designed to allow electrical performance testing, dimensional verification, and field trial before batch production).
• Pre-Wired Combiner Boxes & Distribution Cabinets: Typically 10 to 50 units, depending on internal component configurations, box size, and drilling requirements.
• Component-Level Customization (MCB / MCCB / Isolator / SPD): Usually 50 to 500 units for custom-labeled branding or tailored tripping/voltage parameters.
• New Mold Tooling / Proprietary Enclosures Typically 500 to 1,000+ units to offset upfront mold development and tooling setup costs.

• Standard Project Solutions & Electrical Sizing Free of charge. We provide complimentary component selection, wiring diagrams, and technical consulting to support your project planning and bidding.
• OEM/ODM Enclosure & Layout Customization Free for confirmed orders. Initial 2D/3D layouts, hole drilling templates, and branding mockups are provided at no extra cost once a project or trial order is initiated.
• Custom Tooling / Private Mold Design For completely new proprietary enclosure molds, an upfront mold development fee applies; however, this fee is fully refundable/rebated once cumulative order volumes reach the agreed contract threshold.

Free product brochures and industry solution materials are available:

• Download brochures and manuals https://www.cnlonq.com/service/product-manual-download
• Watch product videos https://www.cnlonq.com/video/product-introduction
• Request one-on-one expert consultation and quotation support
• We recommend contacting sales@cnlonq.com or bzf@cnlonq.com or submitting an inquiry through our website, to receive the latest catalog and product manuals.