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DC Fuses for Solar PV String Protection | 1000V-1500V DC | gPV per IEC 60269-6
The DC Fuse delivers exceptional protection
KRIPAL manufactures DC fuses for photovoltaic applications in the UKRT18PV series, featuring the 22×58 mm cylindrical gPV fuse-link form factor that has become the global standard for PV string and array overcurrent protection. Rated up to 1000V DC operational voltage with current ratings from 2A to 125A, these fuses achieve a 30kA DC breaking capacity through a sand-filled ceramic body with a pure silver fuse element designed to interrupt DC fault currents without the benefit of a natural current zero crossing. The UKRT18PV is compliant with IEC 60269-6 for photovoltaic fuse-links and UL 248-19 for North American PV applications, with a utilization category of gPV meaning the fuse provides full-range protection against both overload and short-circuit conditions in DC photovoltaic circuits. Each fuse-link is supplied with a blown-fuse indicator option and is compatible with the KRIPAL UKRT18PV fuse base that accepts both pin-type and blade-type fuse terminals, supporting DIN-rail and panel-mount installations in combiner boxes and DC distribution cabinets.
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UKRT18PV DC Fuse Holder 1000V 32A 1P 2P for 10x38mm Fuse CE Certified
The Kripal UKRT18PV is a reliable DC Fuse Holder rated at 32A 1000V. Available in 1P/2P for 10x38mm fuses.
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UKRT18PV DC Fuse Holder 1000V 63A 3Pole for 14*51mm Fuse CE Certified
Kripal UKRT18PV is a 3 Pole 63A holder for 14x51mm links. Designed for 1000V DC FUSE applications.
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UKRT18PV DC Fuse Holder 1000V 125A 2P for 22*58 Fuse PV Solar CE Certified
Kripal UKRT18PV is a 2P 125A dc fuse holder 1000v for 22x58mm links. It ensures superior protection for solar PV applications.
Ask a QuoteDC Fuse Selection Guide for Photovoltaic String Protection
A DC fuse provides sacrificial overcurrent protection by melting a calibrated metal element when current exceeds the fuse’s rated value for a defined duration. In PV systems, these fuses are essential within string combiner boxes to protect individual strings against reverse currents from parallel healthy strings, as required by IEC 62548 when the number of parallel strings exceeds three. While DC circuit breakers offer a resettable mechanism, a fuse serves as a reliable “one-shot” device that must be physically replaced after clearing a fault. Despite this, their lower cost, higher DC breaking capacity, and immunity to mechanical wear make them the preferred protection solution at the string level for large-scale PV arrays. This selection guide outlines the critical parameters for choosing the right fuse, including current rating, voltage rating, breaking capacity, and mounting configuration.
UKRT18PV DC Fuse Series Technical Specifications
gPV Fuse-Link Current Rating Selection
The gPV fuse rating should be selected based on the PV string short-circuit current (Isc), typically at least 1.25 times the string Isc to prevent nuisance operation under high irradiance conditions.For example, a PV string with an Isc of 11A commonly uses a 16A or 20A gPV fuse, depending on system design requirements, module specifications, and cable protection needs.In multi-string PV systems, the fuse must also safely interrupt reverse fault currents supplied by parallel strings and clear faults before cable thermal limits are exceeded. KRIPAL gPV fuse-links provide reliable overcurrent protection for residential, commercial, and utility-scale solar applications.
DC Voltage Rating and System Compatibility
UKRT18PV gPV fuse-links are rated up to 1000V DC and are designed for reliable overcurrent protection in photovoltaic systems up to 1000V DC.The fuse voltage rating must be equal to or higher than the maximum PV system voltage to ensure safe fault interruption. Proper selection should consider the array open-circuit voltage (Voc), temperature conditions, and system design requirements.Featuring a non-polarized design, UKRT18PV fuse-links allow flexible installation in either direction while providing reliable DC fault protection for solar PV applications.
Fuse Base and Blown-Fuse Indication Options
UKRT18PV fuse bases are available with flexible connection options to meet different PV combiner box installation requirements, including screw clamp, box lug, and busbar mounting configurations.Integrated blown-fuse indication allows fast identification of failed fuse-links during maintenance. An optional microswitch version provides remote fuse status monitoring for intelligent PV systems and centralized operation platforms.
Fuse Coordination with Upstream DC MCCBs
In PV protection systems, UKRT18PV gPV fuse-links can be coordinated with upstream UKM7Z DC MCCBs to provide selective protection.During string-level faults, the fuse operates first to isolate the affected PV string, while the upstream MCCB remains closed to maintain power generation from healthy strings.KRIPAL provides coordination data to help engineers achieve reliable protection performance and minimize unnecessary system shutdowns in solar PV installations.
Specify DC Fuses for Your PV Combiner Box
- Fuse Sizing Calculator: Submit your string Isc, number of parallel strings and cable size, and we provide the recommended UKRT18PV fuse rating with coordination verification.
- Time-Current Curves: Request I squared t and peak let-through curves in electronic format for your protection coordination study software.
- Combiner Box Design Support: Need help laying out fuse bases in your combiner box enclosure? Request our busbar-mount fuse base 3D STEP files.
Cost-Effective String Protection for PV Installations Worldwide
KRIPAL UKRT18PV DC fuses provide reliable overcurrent protection for photovoltaic systems from residential combiner boxes to utility-scale solar farms. Designed with the gPV utilization category, they are optimized for DC photovoltaic fault conditions that standard gG fuses cannot safely interrupt. The series ensures fast fault clearance, reduced downtime, and cost-effective system protection.
PV String Combiner Box Protection
In 8–24 string PV combiner boxes, each PV string is protected by a UKRT18PV gPV fuse-link, typically selected at 1.25 × Isc. During string faults, healthy strings may feed reverse current into the faulty string. The fuse quickly isolates the fault, protecting PV cables and DC components.Unlike standard gG fuses, UKRT18PV gPV fuse-links are designed for photovoltaic systems, ensuring reliable DC fault interruption under low-overcurrent conditions.
Inverter DC Input Protection
In 500 kW–2 MW central inverters, UKRT18PV fuses protect DC input circuits against severe faults such as DC-link capacitor short circuits and DC bus faults. With a DC breaking capacity of up to 30 kA, the fuse quickly interrupts high-energy fault currents, limiting let-through energy and protecting power semiconductor devices.Fuse status monitoring can be integrated into inverter control systems to trigger protection actions and prevent operation under fault conditions.
Battery Energy Storage Protection
In lithium-ion battery systems, DC fuses help protect battery circuits against high-energy faults such as internal short circuits. High fault currents in low-voltage battery systems can generate significant thermal stress, requiring fast and reliable fault interruption.The fuse’s low I²t let-through helps reduce fault energy and protect connected components. Its non-polarized design enables reliable operation in DC systems with bidirectional current flow during charging and discharging.
DC Distribution & Industrial Applications
In low-voltage DC distribution systems, UKRT18PV fuses protect branch circuits supplying critical loads such as control systems and industrial equipment. They provide reliable protection against overload currents and short-circuit faults, while the fuse indicator enables quick fault identification in high-density DC panels.
Solar Water Pumping Systems
In off-grid PV pumping systems, UKRT18PV fuses protect DC circuits, controllers, and connected equipment against overcurrent faults. They are designed to withstand normal startup currents while providing fast fault isolation during abnormal conditions. DIN-rail fuse bases and visual indicators simplify installation and field maintenance.
Protect Your PV Strings with gPV Fuse-Links
- Fuse Coordination Report: Submit your combiner box single-line diagram for a full selectivity study showing UKRT18PV fuses coordinated with upstream MCCBs.
- IEC 60269-6 Compliance Package: Obtain gPV type-test certificates and pre-arcing I squared t data for your project technical due diligence.
- Bulk Fuse-Link Supply: Order UKRT18PV fuse-links in bulk packs of 100 with your combiner box production volumes for just-in-time delivery to your assembly line.
KRIPAL DC Fuse Manufacturing: Precision Elements for Predictable Protection
KRIPAL DC fuses are manufactured through controlled processes using precision-formed silver alloy fuse elements and high-purity quartz sand filling to ensure reliable arc-quenching performance. Ceramic fuse bodies and end-cap assemblies are produced with controlled joining processes to maintain mechanical strength and electrical reliability.Each production batch undergoes quality inspection and verification, while DC breaking capacity and performance testing are conducted according to applicable IEC and UL standards during type testing.
Precision-Stamped Silver Fuse Elements
Silver alloy fuse elements are precision-stamped using controlled tooling processes, with tight dimensional control on reduced-section areas that define the melting characteristics. Element geometry is verified during tooling setup to ensure consistent gPV time-current performance and reliable fault interruption.
Quartz Sand Filler Compaction Process
High-purity quartz sand with controlled grain size distribution (99.5 percent SiO2 minimum, particle size 0.2 to 0.4 mm) is compacted around the fuse element under precision vibration. The compaction density is verified by X-ray inspection of sample fuses to confirm uniform filling around the element, which determines arc quenching performance during DC interruption.
DC Breaking Capacity Testing Per Production Batch
Sample fuses from each production lot are tested on a DC test circuit at the rated breaking capacity (up to 30kA at 1000V DC). Oscillographic records of let-through current and I-squared-t values are compared against published data to confirm that production units match type-tested performance.
End-Cap Crimping and Ceramic Body Sealing
Silver-plated copper end caps are crimped onto ceramic fuse bodies under controlled pressure, with crimp depth verified on a sampling basis. Epoxy resin sealing of end-cap joints is cured under temperature-controlled conditions, and each completed fuse undergoes a continuity test and visual inspection for seal integrity.
Distributor Stock Holding Programs for DC Fuses
KRIPAL supports distributor inventory programs by aligning agreed stock levels with standard DC fuse models. Shipments are planned based on demand forecasts and historical consumption data to ensure continuous product availability and efficient replenishment cycles.
Private Label and OEM Branding for DC Fuses
KRIPAL offers OEM and private label solutions for DC fuses, including laser-marked part numbers aligned with customer catalog requirements, customized branding on packaging, and multilingual instruction materials. Both branded and unbranded supply options can be supported depending on customer requirements.
Multi-Region Certification and Compliance Support
KRIPAL DC fuses are designed according to applicable international standards, including IEC 60269-6 for PV gPV applications and relevant UL 248 series requirements for North American markets. CE and UKCA declarations are provided to support regional market access.Technical documentation is maintained through controlled processes to ensure alignment with applicable standards and support PV system design verification.
Direct Technical Access to KRIPAL Production Engineers
KRIPAL provides direct technical support from engineers involved in the design and validation of DC fuse products. Application-related questions are handled by our engineering team, ensuring accurate technical guidance for system integration and protection coordination.Response times are typically within 24 hours during China business hours, depending on the complexity of the application.
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