JY SMRS Dual Sensing Fuse Wire

Scope of Delivery Dual sensing fuse wire Installation Instruction Sheet Quality Certificate

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I. Product Overview

A Dual Sensing Fuse Wire designed specifically for 15kV American-style transformer substations, ring main units, and other power distribution equipment . It is compatible with PRNT series plug-in fuses and has both overload and short-circuit protection functions. It adopts a high-performance alloy fuse wire and a high-strength insulating tube structure, which can quickly interrupt fault current and protect transformers and lines from overcurrent damage. It is a core component of overcurrent protection in American-style medium-voltage power distribution systems.

II. Product Characteristics

1. Electrical and protective performance

Dual-sensitivity protection features : It has both overload protection and short-circuit protection functions. It melts through heat accumulation in the case of low-multiple overload and melts through current limiting in the case of high-multiple short circuit, adapting to different fault scenarios of transformers and lines.
Excellent current limiting characteristics : It adopts high-performance alloy fuse, which can cut off the current within half a cycle during short circuit, effectively limiting the peak fault current and reducing the impact of fault on equipment. The breaking capacity can reach 20/31.5kA.
Reliable insulation performance : The fuse tube is made of high-strength epoxy glass fiber material, which has excellent insulation performance and can withstand the rated voltage of 15.5kV system and short-time overvoltage. It has high insulation strength and no risk of breakdown or flashover.
Clear fuse indication : The built-in fuse indicator can intuitively display the fault status after the fuse blows, making it easy for maintenance personnel to quickly troubleshoot the fault.

2. Structural and Safety Features

Standardized modular design : Compatible with PRNT series plug-in fuses, it can be directly installed in the fuse assembly, making installation convenient and replacement can be done without power outages, greatly improving operation and maintenance efficiency.
Anti-misinstallation design : The interface size is standardized and can only be matched with fuse components of the corresponding specifications, eliminating the risk of misinstallation; it has a built-in positioning structure to prevent loosening and falling off after installation.
High mechanical strength : The fuse tube is made of high-strength epoxy glass fiber material, which is impact-resistant and vibration-resistant, and can withstand mechanical stress during transportation, installation and operation without the risk of deformation or breakage.

3. Environmental and Weather Resistance

Strong wide temperature adaptability : It can adapt to a wide temperature range of -40℃ to +90℃. The performance of the fuse and insulation material does not degrade under high and low temperatures, and there is no risk of cracking or embrittlement. It is suitable for various outdoor and indoor scenarios.
Excellent moisture and dirt resistance : The fully sealed structure of the fuse tube is moisture-proof, waterproof, dirt-proof, and salt spray-proof. It can operate stably for a long time in harsh environments such as underground, humid, and dusty environments, and is not afraid of rain or condensation.
Long service life : Anti-aging, anti-ultraviolet, and resistant to ozone corrosion. Under normal working conditions, the service life can reach more than 10 years. The fuse is easy to replace, reducing the later maintenance cost.

III. Technical Parameters

Parameter categories	project	Technical indicators
Rated electrical parameters	Applicable system voltage (Un)	10kV
	Rated voltage (Ue)	15.5kV
	Rated current (Ie)	5~200A (Multiple specifications available, such as 63A, etc.)
	Rated frequency (fn)	50Hz/60Hz
	Power frequency withstand voltage	42kV/5min (dry test), no breakdown, no flashover
	Lightning impulse withstand voltage	95kV (peak value), no breakdown, no flashover
	Rated short-circuit breaking current	20kA/31.5kA (optional)
	Current limiting characteristics	Short-circuit current limiting factor ≤ 0.25
	Protective features	Dual-sensitive type, combining overload and short-circuit protection
Structural and material parameters	Main material	Epoxy fiberglass (fuse tubes), high-performance alloys (fuse elements), tin-plated copper (conductive contacts)
	Compatible fuse models	PRNT series 15.5kV plug-in fuses
Environmental parameters	Applicable altitude	≤2000m (Customization available for high altitudes)
	Ambient temperature	-40℃/ +90℃ (operating temperature), -40℃/ +70℃ (storage temperature)
	relative humidity	≤100% (no condensation)
	Seismic resistance level	Level 8
Implementation Standards		IEEE C37.42, GB/T 15166, GB/T 11022

IV. Scope of Application

Applicable voltage level : 10kV AC medium voltage power distribution system, compatible with American-style prefabricated substations and ring main units with a maximum operating voltage of 17.5kV.
Applicable equipment scenarios :
The PRNT series plug-in fuses in 15kV American-style prefabricated substations and ring main units serve as core protection components to achieve overload and short-circuit protection for transformers and lines.
American-style box-type transformer substations for urban power distribution networks, power distribution systems for industrial and mining enterprises, and American-style power distribution equipment for new energy (photovoltaic/wind power) step-up substations;
Overcurrent protection for American-style power distribution equipment in various scenarios, including indoor/outdoor power distribution rooms, underground utility tunnels, and cable tunnels.
Function and Purpose : Limits overload and short-circuit currents in power distribution systems, protects transformers and lines from overcurrent damage, and provides insulation isolation, making it a safe and reliable core component for overcurrent protection in American medium-voltage power distribution systems.

V. Usage Conditions

1. Normal operating conditions

Altitude: ≤2000m;
Ambient temperature: -40℃~+90℃; equipment operating temperature complies with relevant standards.
Relative humidity: ≤100% (no condensation);
Environmental conditions: No corrosive gases, no flammable or explosive media, no severe vibration or impact;
Installation method: Compatible with PRNT series plug-in fuse assemblies, can be installed horizontally or vertically, and the installation space must meet the operation requirements.

2. Special usage conditions (customization required)

The altitude exceeds 2000m;
The ambient temperature exceeds the range of -40℃ to +90℃;
Severely polluted, salt spray, and chemically corrosive environments;
High vibration and high impact conditions;
Non-standard fuse assembly interface specifications;
Special current ratings and breaking capacity requirements.

VI. Installation and Maintenance

1. Installation Requirements

Before installation, inspect the product appearance for cracks, damage, bubbles, and undamaged insulation surfaces; check that the fuses are intact and free of rust, and that the fuse indicator is functioning properly.
Clean the interface surface of the fuse assembly to remove oil, dust, and foreign matter, and ensure that the interface is dry and clean.
Slowly push the fuse tube into the fuse assembly to ensure proper installation and lock the positioning structure.
After installation, install the fuse assembly into the fuse holder of the equipment and check that the installation is secure, without looseness or tilting.

2. Maintenance Requirements

Regularly inspect the appearance of the fuse tube; ensure it is free of cracks, discharge marks, and dirt accumulation, and that it is securely installed without any looseness.
Regularly check the status of the fuse indicator. If the indicator pops up, it means that the fuse has blown and you need to replace it with a fuse tube of the same specification immediately.
Clean the surface of the fuse tube to remove dust and dirt, keep the insulation surface dry and clean, and avoid corrosion from oil and chemicals.
After a fuse blows, it must be replaced with a dual-sensitive fuse tube of the same specification. It is strictly forbidden to use fuses of different specifications or to directly short-circuit them, otherwise the protection will fail and cause a safety accident.
When replacing fuses, special insulated tools must be used. It is strictly forbidden to operate live fuses by hand. Power distribution safety regulations must be strictly followed during operation.

VII. Precautions

The product must be installed, debugged, and maintained by professional electrical personnel with medium-voltage power distribution construction qualifications. Operation by non-professional personnel is strictly prohibited.
The product must be used with the corresponding PRNT series fuse assembly. It is strictly forbidden to use fuses of different voltage or current ratings, otherwise it will lead to protection failure and safety accidents.
Fuse tubes must not be disassembled or modified without authorization, otherwise the warranty and safety guarantee will be lost. It is strictly forbidden to use non-specialized tools to forcibly install or disassemble them.
After a fuse blows, it must be replaced with a dual-sensitive fuse tube of the same specification. It is strictly forbidden to use a substitute fuse or short-circuit it, otherwise it will lead to serious consequences such as equipment damage and fire.
When storing, it should be placed in a dry, ventilated, and cool environment, avoiding direct sunlight, high temperature, humidity, and compression. It is strictly forbidden to contact with sharp objects that may damage the insulation layer.
When replacing fuses while the circuit is energized, it is essential to strictly adhere to power distribution safety regulations, take appropriate safety precautions, and strictly prohibit any unauthorized operations.

VIII. Model Description

Model Identification	meaning
JY	Product series code
SMRS	Dual Sensing Fuse Wire
PRNT 15.5kV	Compatible with PRNT series 15.5kV plug-in fuses
63-AMP	Rated current rating 63A (multiple specifications available)

IX. Implementation Standards and Certification

International Standard: IEEE C37.42 “High Voltage Fuse Standard”;
National standards: GB/T 15166 “AC High Voltage Fuses”, GB/T 11022 “Common Technical Requirements for Standards on High Voltage Switchgear and Controlgear”, DL/T 640 “High Voltage AC Drop-out Fuses”;
The product has passed the type test of the National High Voltage Electrical Apparatus Quality Supervision and Inspection Center and meets national electrical safety standards.

X. After-sales service

Product warranty period: 18 months from the date of manufacture, or 12 months from the date of commissioning (whichever comes first).
During the warranty period, products will be repaired or replaced free of charge if quality issues arise.
We provide technical support, installation guidance, and customized services (adaptation to special current ratings and operating conditions).

Document Description

The technical parameters in this manual are based on standard operating conditions. Special operating conditions need to be customized according to actual needs. The final specifications shall be subject to the product technical agreement and type test report.