JY BLQ-17/50 17/50kV Elbow Surge Arrester

I. Product Overview

The JY BLQ-17/50 17/50kV Elbow Surge Arrester is a separable zinc oxide surge arrester specifically designed for 10kV (17kV level) medium-voltage power distribution systems. It features a fully insulated, fully sealed, touch-accessible elbow structure, integrating zinc oxide valve plates and cable accessory interfaces. It can be directly used with 15kV 200A standard bushings and elbow joints to provide overvoltage protection for cable lines and power distribution equipment. Widely used in ring main units, prefabricated substations, cable branch boxes, and other equipment, it is an indispensable lightning protection component in medium-voltage power distribution systems.

II. Product Characteristics

1. Electrical and protective performance

• Employing high-performance zinc oxide valve plates , these valves exhibit excellent volt-ampere characteristics, low residual voltage, and large current capacity, effectively limiting lightning overvoltage and switching overvoltage, and protecting power distribution equipment from overvoltage damage.
• With its fully insulated and sealed structure, the valve plate is unaffected by moisture and dust, ensuring stable long-term operation without the risk of aging or deterioration.
• The elbow-type integrated design with built-in conductive contacts allows for direct connection to a standard 15kV 200A bushing socket, making installation convenient and requiring no additional wiring.
• It has a built-in grounding lead, which can achieve reliable grounding and effectively release lightning current and fault current. The grounding resistance ≤4Ω is sufficient to meet the requirements.

2. Structural and Safety Features

• With a fully insulated, fully sealed, and touch-accessible structure, the outer layer has high insulation strength, allowing direct contact with the outer casing during operation without the risk of electric shock, thus ensuring the safety of maintenance personnel.
• The elbow-type interface is standardized and compatible with 15kV 200A standard bushing sockets. It can be interchanged with elbow-type cable joints and bushing joints of the same specifications, and has strong compatibility.
• The design prevents mis-insertion and incorrect connection, with a unique interface size to eliminate the risk of incorrect installation; it also features a built-in positioning and locking structure to prevent loosening and falling off after installation.
• The outer shell is made of weather-resistant EPDM rubber, which has high mechanical strength, is impact-resistant and vibration-resistant, and can withstand mechanical stress during transportation, installation and operation.

3. Environmental and Weather Resistance

• With excellent weather resistance, it can adapt to a wide temperature range of -40℃ to +90℃. The elasticity of the rubber and the performance of the zinc oxide valve plate do not decrease under high and low temperatures, and there is no risk of cracking or embrittlement. It is suitable for various outdoor and indoor scenarios.
• Moisture-proof, waterproof, stain-proof, and salt spray-proof, with an IP67 protection rating, it can operate stably for a long time in harsh environments such as underground, humid, and dusty conditions, and is not afraid of rain or condensation corrosion.
• It is resistant to aging, ultraviolet rays, and ozone corrosion, with a service life of over 20 years. It requires no maintenance and reduces subsequent operation and maintenance costs.

4. Mechanical and Adaptation Characteristics

• It has high mechanical strength, is impact and vibration resistant, and can withstand mechanical stress during transportation, installation and operation without deformation or damage risk. Its seismic resistance level reaches level 8.
• It is compatible with 15kV 200A standard bushing socket interfaces and can be directly installed on the equipment bushings of ring main units, prefabricated substations, and cable branch boxes without the need for additional adapters.
• The interface is standardized and conforms to IEEE 386 and relevant domestic standards, and can be interchanged with the bushing sockets of mainstream 15kV power distribution equipment.

III. Technical Parameters

Parameter categories	project	Technical indicators
Rated electrical parameters	System nominal voltage (Un)	10kV
	Surge arrester rated voltage (Ur)	17kV
	Surge arrester continuous operating voltage (Uc)	13.6kV
	Nominal discharge current	5kA
	Lightning impulse residual voltage (5kA)	≤50kV
	Operating impact residual pressure (0.5kA)	≤38kV
	DC reference voltage (U1mA)	≥24kV
	Leakage current (0.75U1mA)	≤50μA
	Power frequency withstand voltage	42kV/5min (dry test), no breakdown, no flashover
	Lightning impulse withstand voltage	95kV (peak value), no breakdown, no flashover
Structural and material parameters	Main material	EPDM (ethylene propylene diene monomer) rubber (insulation layer), zinc oxide valve plate (core component), tin-plated copper (conductive contact).
	Protection level	IP67
	Interface Standard	15kV 200A American standard bushing connector
	grounding method	It comes with a grounding lead and can be directly grounded.
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 386, GB 11032, GB/T 11022, DL/T 804

IV. Scope of Application

1. Applicable voltage level : 10kV AC medium voltage power distribution system, compatible with equipment bushing interfaces with a maximum operating voltage of 17.5kV.
2. Applicable equipment scenarios :
3. Bushing interfaces for power distribution equipment such as 15kV ring main units, prefabricated substations, cable branch boxes, and American-style prefabricated substations, serving as overvoltage protection for lines/equipment;
4. Used in conjunction with a 15kV 200A bushing socket to provide lightning protection for cable lines and power distribution equipment;
5. Overvoltage protection for urban power distribution cable lines, power distribution systems of industrial and mining enterprises, and power distribution interfaces of new energy (photovoltaic/wind power) substations;
6. Overvoltage protection for equipment in various scenarios, including indoor/outdoor power distribution rooms, underground utility tunnels, and cable tunnels.
7. Function and Purpose : To limit lightning overvoltage and switching overvoltage in the power distribution system, protect cable lines and power distribution equipment from overvoltage damage, and improve the operational safety and reliability of the power distribution system.

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 standard 15kV 200A bushing socket interface, horizontal/vertical installation is acceptable, 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 equipment sleeve socket interface specifications;
• Special lightning protection requirements and high pollution levels.

VI. Installation and Maintenance

1. Installation Requirements

• Before installation, inspect the product appearance for cracks, damage, bubbles, and undamaged insulation surfaces; check that the grounding lead is intact and free of rust, and that all accessories are complete.
• Clean the surface of the equipment sleeve socket interface to remove oil, dust, and foreign objects, ensuring the interface is dry and clean.
• Apply a special silicone grease lubricant evenly to the inner wall of the surge arrester interface to avoid damaging the insulation layer during installation.
• Slowly push the surge arrester into the bushing socket interface to ensure it is fully in place and lock the positioning structure; connect the grounding lead to the grounding grid, with a grounding resistance ≤4Ω.
• After installation, insulation resistance and DC reference voltage tests should be performed. Only after passing the tests can the equipment be put into operation.

2. Maintenance Requirements

• Regularly inspect the appearance of the surge arrester; check for cracks, discharge marks, and dirt accumulation, and ensure that the grounding lead is securely connected without looseness.
• Regularly test insulation resistance, DC reference voltage, and leakage current to ensure performance meets requirements and to promptly identify potential faults.
• Clean the surface of the surge arrester to remove accumulated dust and dirt, keep the insulation surface dry and clean, and avoid corrosion from oil and chemicals.
• If a surge arrester shows abnormalities such as cracks, damage, discharge, or excessive leakage current, it should be immediately shut down and replaced. It is strictly forbidden to operate a surge arrester with defects.
• Special insulated tools must be used for plugging and unplugging surge arresters. It is strictly forbidden to operate live surge arresters by hand. Power distribution safety regulations must be strictly followed during operation.

VII. Precautions

1. 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.
2. The product must be used with the corresponding specification of equipment bushing socket. It is strictly forbidden to use interfaces with different voltage levels or different current levels, otherwise it will lead to insulation failure and safety accidents.
3. Surge arresters 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 surge arresters.
4. The grounding of the surge arrester must be reliable, with a grounding resistance of ≤4Ω; otherwise, it will affect the lightning protection effect and may even cause a safety accident.
5. 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.
6. When operating surge arresters while they are 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
BLQ	Lightning arrester series code
17/50	The surge arrester has a rated voltage of 17kV and a residual voltage of ≤50kV under the nominal discharge current.
Elbow Surge Arrester	Elbow-type surge arrester, a zinc oxide surge arrester with a detachable elbow-type interface.

IX. Implementation Standards and Certification

• International standards: IEEE 386 “Medium-voltage separable cable connectors” and IEC 60099-4 “AC gapless metal oxide surge arresters”;
• National standards: GB 11032 “AC gapless metal oxide surge arresters”, GB/T 11022 “Common technical requirements for high voltage switchgear and controlgear standards”, DL/T 804 “Guidelines for the use of metal oxide surge arresters in AC power systems”;
• 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 specifications and working 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.

Appendix: Product outline diagram