Fixed Switchgear

 

 

 

XGN 17 - 40.5

X	Box-shaped metal enclosed structure
G	Fixed switchgear
N	Indoor usage scenarios
17	Product Design Serial Number (Third Generation Optimized 35kV Cabinet)
40.5	The equipment's maximum rated operating voltage is 40.5kV (corresponding to a system rated voltage of 35kV).

 

 

Serial Number	Technology Projects	Parameter Indicators
1	Rated system voltage	35kV
2	Maximum operating voltage	40.5kV
3	Rated frequency	50Hz
4	Main bus rated current	1250A, 1600A, 2000A
5	Branch circuit rated current	630A, 1250A, 1600A
6	Rated short-circuit breaking current	25kA, 31.5kA
7	Rated short-time withstand current (4s)	25kA, 31.5kA
8	Rated peak withstand current	63kA, 80kA
9	1-minute power frequency withstand voltage	95kV between phases/to ground; 118kV isolation break
10	Lightning impulse withstand voltage	185kV between phases/to ground; 215kV isolation break
11	Core configuration	35kV high-voltage disconnect switch, vacuum circuit breaker, microprocessor-based integrated protection system, high-voltage grounding switch
12	Protection level	IP2X (Indoor High Voltage Distribution Standard)
13	Mechanical life	Circuit breaker 10,000 cycles, disconnector 2,000 cycles
14	Operating ambient temperature	-10℃～+40℃
15	Five-proof function	Mechanical + Electrical Dual Five-Protection Interlock

 

 

The XGN17-40.5 switchgear adopts a fully enclosed welded steel plate enclosure structure, which features high overall strength, resistance to deformation, and excellent seismic performance. The cabinet is strictly divided into compartments: the busbar compartment, circuit breaker compartment, cable compartment, and instrument control compartment are independent of each other. Insulating partitions and pressure relief channels are installed between each compartment to effectively isolate faults, release internal arc pressure, and prevent fault escalation. The equipment comes standard with four core components: a 35kV high-voltage disconnect switch, a 35kV vacuum circuit breaker, an intelligent microcomputer-based integrated protection device, and a high-voltage grounding switch . It is equipped with a complete operating mechanism and interlocking system, meeting all the requirements for safe operation, accurate protection, reliable isolation, and maintenance grounding of 35kV high-voltage systems.

 

■ 35kV High Voltage Disconnect Switch

This cabinet is equipped with a dedicated 35kV indoor high-voltage disconnect switch, which serves as the core component for electrical isolation in high-voltage circuits. It provides sufficient insulation distance and visible space at the break point, meeting the insulation requirements for 40.5kV high voltage. The equipment has no arc-extinguishing function and is only used for opening and closing circuits under no-load conditions. After the circuit breaker trips and disconnects the power, it forms a clear and reliable electrical disconnect point, providing a safe insulation barrier for the maintenance of equipment and lines within the cabinet.

The disconnector contacts are made of high-quality copper plated with silver, resulting in low contact resistance, low heat generation, oxidation resistance, and stable current carrying capacity. The operating mechanism boasts high mechanical strength, precise operation, and is free from jamming or deformation. The equipment features a built-in dedicated mechanical interlock, strictly adhering to the logic that "the disconnector can only be operated after the circuit breaker has been opened," completely eliminating the possibility of malicious electrical misoperation such as opening or closing the disconnector under load, and is compatible with the safety operation and maintenance standards for 35kV high-voltage systems.

 

■ 35kV High Voltage Vacuum Circuit Breaker

The main switch of the cabinet adopts a 35kV indoor high-voltage vacuum circuit breaker, which is the core actuator for circuit switching and fault protection. The equipment uses a high-vacuum arc-extinguishing chamber, which is free of oil, exhaust gas and pollution. It has a fast arc-extinguishing speed, excellent insulation recovery performance, no risk of reignition and overvoltage, and is suitable for frequent operation and long-term continuous operation of 35kV high-voltage systems.

The circuit breaker is fixedly installed in an independent circuit breaker compartment, featuring a robust structure and strong seismic resistance. It possesses dual operation functions: electric energy storage and electric opening/closing, as well as manual energy storage and manual opening/closing. It is adaptable to both remote automatic control and on-site emergency manual operation. The equipment can accurately isolate system faults such as short circuits, overloads, and leakage currents, with fast response speed and high protection reliability. It effectively protects downstream transformers, lines, and high-voltage electrical equipment, serving as a core safety barrier for the 35kV power distribution system.

 

■ Intelligent Microcomputer Integrated Protection and Control Device

The instrument control room is equipped with a 35kV dedicated microcomputer-based integrated protection device, replacing traditional electromagnetic relays. It integrates measurement, protection, control, alarm, communication, and event recording, enabling intelligent, unattended operation and maintenance of high-voltage circuits. The device is suitable for various high-voltage load protection scenarios, including 35kV lines, transformers, capacitors, and motors.

 

Core functions include : three-stage current protection, overload protection, zero-sequence grounding protection, overvoltage and undervoltage protection, undervoltage tripping, and reclosing. It can collect real-time operating parameters such as three-phase voltage, three-phase current, active power, reactive power, and frequency, with the operating status displayed intuitively on the screen. In case of a fault, it automatically issues audible and visual alarms, precisely drives the circuit breaker to trip, and simultaneously stores the fault time, fault type, and action data for quick fault diagnosis. It comes standard with a communication interface, supports four remote functions (remote control, remote monitoring, remote isolation, and remote telemetry), and can be connected to the substation's backend system for remote centralized monitoring and intelligent management. The device has built-in anti-maloperation and anti-failure-to-operation logic, ensuring accurate protection settings and stable operation.

 

■ 35kV High Voltage Grounding Switch (Grounding Knife)

The cabinet cable compartment is equipped with a high-voltage dedicated grounding switch, which has a 4-second short-time withstand capability for short-circuit grounding current and is a core safety protection device for 35kV high-voltage equipment maintenance. When power is off for maintenance of lines, cables, and cabinet equipment, the equipment reliably grounds the line and cable sides, quickly releasing residual charge and dissipating induced high voltage, completely eliminating electric shock accidents caused by residual voltage, induced current, or sudden power restoration.

The grounding switch is equipped with strict mechanical interlocking logic, and can only be closed and grounded after the circuit breaker is fully open, the disconnecting switch is fully open, and the circuit is completely de-energized; when the grounding switch is closed, the energizing operation of the disconnecting switch and the circuit breaker is forcibly blocked, eliminating major safety accidents caused by closing and energizing with the grounding wire connected, which fully complies with the high-voltage power safety work regulations.

 

■ Five-proof interlocking and pressure relief protection system

The cabinet is equipped with a complete set of mechanical and electrical dual five-proof interlocking functions, comprehensively covering high-voltage prevention of misoperation: preventing accidental opening and closing of circuit breakers, preventing the operation of disconnecting switches under load, preventing the closing of grounding switches while energized, preventing the closing of power supply with the ground wire connected, and preventing accidental entry into energized compartments. The interlocking logic of each operating mechanism is rigorous and reliable, with hardware-mandated interlocking that cannot be manually bypassed by short-circuiting, thus eliminating all high-voltage misoperation accidents at the source. Simultaneously, the top of the cabinet is equipped with a dedicated pressure relief channel, allowing for rapid pressure release of internal fault arcs, ensuring the structural integrity of the cabinet and the safety of personnel and equipment.

 

 

1. High-voltage power distribution systems of 35kV substations, switching stations, and distribution rooms in various regions;

2. 35kV high-voltage power supply, substation, and control systems for industrial and mining enterprises, large factories, and industrial parks;

3. Power distribution equipment for 35kV booster stations of new energy photovoltaic, wind power, and energy storage power stations;

4. 35kV power supply systems for critical loads such as rail transit, key municipal projects, hospitals, and data centers;

5. Various indoor high-voltage power distribution scenarios requiring 35kV power distribution, fault protection, safety isolation, and maintenance grounding.

 

 

■ Installation Environment Requirements

1. The equipment is a dedicated indoor high-voltage equipment and must be installed in a dry, ventilated, clean, and sealed 35kV high-voltage distribution room, free from corrosive gases, flammable and explosive dust, severe vibration, and strong electromagnetic interference.

2. The foundation channel steel is level and level, and the load-bearing capacity meets the standards. The cabinets are firmly fixed to the ground, arranged neatly, and the verticality meets the specifications. The cabinets are tightly spliced together with uniform gaps.

3. The cabinet, grounding switch, and secondary circuit must be independently and reliably grounded, with a grounding resistance of ≤4Ω, and the grounding connection must be firm and have good conductivity;

4. The power distribution room should be properly sealed off to prevent dust, moisture, condensation, and small animals from blocking it, and the ambient temperature and humidity should meet the long-term operating requirements of the equipment.

 

■ Pre-installation inspection

1. Check that the cabinet is in good condition, the paint is intact, the cabinet body is not deformed, and the cabinet doors, locks, and operating mechanisms are flexible and reliable;

2. Verify that the model parameters of the vacuum circuit breaker, disconnector, grounding switch, and microprocessor protection device are consistent with the design drawings, and that the components are intact and undamaged;

3. Check that the primary contacts and busbar connections are secure, without looseness, oxidation, or damage, and that the insulating sleeves are clean, intact, and free of creepage marks.

4. The five-proof interlocking function was tested throughout the process. The locking logic of each mechanism was accurate, the action was smooth, there was no jamming, and there was no failure.

5. Before powering on, conduct insulation resistance tests and withstand voltage tests to confirm that the equipment's insulation performance meets the standards and that there are no potential hazards such as short circuits, grounding, or leakage.

 

■ Standard Switching Operation Procedures

1. Power supply operation procedure : Close all cabinet doors → Confirm grounding switch is open → Close high voltage disconnect switch → Circuit breaker energy storage → Circuit breaker is closed, and the equipment operates normally under load.

2. Power outage operation procedure : Circuit breaker trips to disconnect the load → Confirm that the circuit is de-energized → Trip the high-voltage disconnect switch → If maintenance is required, close the grounding switch and lock the device.

3. Maintenance procedure : Completely disconnect the power to the equipment → verify that there is no voltage → close the grounding switch → open the cabinet door to carry out maintenance work.

4. During daily operation, it is strictly forbidden to arbitrarily disable the microcomputer protection or change the protection settings. After a fault trip, the fault record must be checked and potential hazards investigated. Power can only be restored after confirming that there is no fault.

5. All switching operations must be performed by certified high-voltage electricians, and the operation ticket system must be strictly implemented to prevent violations of regulations.

 

 

1. Daily inspection: Check daily that the cabinet instruments and microcomputer protection displays are normal, with no alarms, no abnormal noises, no odors, no traces of discharge, the cabinet door is tightly closed, and the equipment operating current and voltage are stable;

2. Monthly maintenance: Clean the insulation components and bushing surfaces inside the cabinet of dust and dirt, check the contact status of disconnecting switches and circuit breakers, tighten the primary and secondary wiring terminals, and test the flexibility of the interlocking mechanism;

3. Quarterly maintenance: Verify the microcomputer protection settings, alarm, trip, and reclosing functions; test the grounding switch closing continuity performance; and check the reliability of the circuit breaker's energy storage and opening/closing operations.

4. Annual maintenance: Conduct insulation withstand voltage tests, comprehensively test the circuit insulation performance, maintain the operating mechanism, replace aging auxiliary parts, and simulate fault transmission tests to ensure accurate and reliable protection actions;

5. During the rainy and humid seasons, strengthen ventilation and dehumidification in the power distribution room to prevent condensation on insulating components, insulation degradation, and avoid creepage, discharge, and short circuit faults.

 

 

Fault phenomenon	Cause of the fault	processing method
The circuit breaker cannot be closed.	The mechanism is not storing energy, the five-prevention interlock is locked, the protection alarm has not been reset, the isolating switch is not in place, and there is a secondary circuit fault.	Complete the energy storage of the mechanism, check and unlock the interlocks, reset the protection devices, repair the secondary control circuit, and confirm that the disconnect switch is in place.
Disconnect switch operation is stuck and cannot be activated.	Circuit breaker not tripped, interlock not unlocked, mechanism corroded and stuck, mechanical deformation.	Confirm the circuit breaker is fully tripped, unlock the interlock, clean and lubricate the operating mechanism, and correct any deformed components.
Grounding switch cannot be closed/opened	Live-line interlock protection activation, mechanism jamming and corrosion, interlocking logic not met.	Confirm that the circuit is completely de-energized and the switch is fully open. Clean and maintain the mechanism and remove any mechanical jamming.
Frequent alarms and malfunctions in microcomputer protection systems	Inappropriate protection settings, abnormal sampling circuit, line interference, aging of equipment	Verify and correct protection settings, troubleshoot current and voltage sampling circuits, shield against interference, and repair or replace protection devices.
Abnormal noises during equipment operation and localized overheating	Poor contact of contacts, loose terminals, excessive load, and discharge due to insulation contamination.	Tighten wiring terminals during power outage, grind and repair oxidized contacts, control operating load, and thoroughly clean insulation dust inside the cabinet.

 

 

1. Equipment installation, commissioning, switching operations, maintenance and repair must be carried out by certified high-voltage electricians, and the 35kV high-voltage electrical safety operation procedures and power safety work procedures must be strictly followed.

2. During the operation of the equipment while it is energized, it is strictly forbidden to open the cabinet door, touch the busbars, bushings, contacts and all energized parts inside the cabinet, and it is strictly forbidden to disassemble the equipment components without authorization;

3. Strictly follow the 35kV switching operation sequence: when power is supplied, close the isolator first, then close the circuit breaker; when power is de-energized, open the circuit breaker first, then open the isolator. It is strictly forbidden to operate the isolator under load.

4. All cabinet inspections and line maintenance work must strictly follow the safety procedures of power off, voltage testing, grounding, tagging, and barrier installation . Work can only proceed after the grounding switch is reliably closed.

5. It is strictly forbidden to change the microcomputer protection settings, disable the protection function, or short-circuit the five-prevention interlocking circuit without authorization. It is strictly forbidden to operate the equipment without protection or interlocking and with defects.

6. Regularly inspect the cabinet's grounding, insulation performance, and interlocking mechanism reliability to prevent safety accidents caused by grounding failure, insulation degradation, or interlocking malfunction.

 

 

This product is manufactured and inspected strictly according to national standards. Before leaving the factory, it undergoes comprehensive tests including insulation withstand voltage, short-circuit withstand, mechanical operation, five-proof interlocking, protection transmission, and continuity performance to ensure qualified equipment performance and stable operation. The equipment comes with a 24-month overall warranty, and core components (vacuum circuit breaker, disconnector, grounding switch, and microcomputer protection device) are covered by the original manufacturer's warranty service. During the warranty period, the manufacturer will repair or replace any equipment structural defects or functional failures caused by non-human-caused damage or force majeure. Failures caused by unauthorized modification, improper operation, overload operation, human-caused damage, harsh environmental conditions, or natural disasters are not covered by the warranty.