Environmentally Friendly Gas Switchgear

 

 

 

 

 

Normal usage conditions

◆Ambient air temperature: Upper limit +40℃, Lower limit -40℃

◆Humidity: The daily average relative humidity is no more than 95%; the monthly average is no more than 90%.

◆Water vapor pressure: Daily average not exceeding 2.2 kPa; Monthly average not exceeding 1.8 kPa;

◆Altitude not exceeding 3000m.

◆The surrounding air is not significantly polluted by dust, smoke, corrosive and flammable gases, vapors or salt spray.

◆The amplitude of electromagnetic interference induced in the secondary system shall not exceed 1.6kV.

 

According to the standard

◇ GB 1984 High-voltage AC circuit breakers

◇ GB1985 High-voltage AC disconnect switches and grounding switches

◇ GB 3804 3.6kV~40.5kV High Voltage AC Load Switch

◇ GB 3906 3.6 kV ~40.5 kV AC metal-enclosed switchgear and controlgear

◇ GB4208 Enclosure Protection Rating (IP Code)

◇ Common technical requirements for GB/T11022 standard for high voltage switchgear and controlgear

◇ GB/T16927 1 High Voltage Testing Techniques - Part 1 General Definitions and Test Requirements

◇ DL/T403 Technical Conditions for Ordering 12kV~40.5kV High Voltage Vacuum Circuit Breakers

◇ DL/T404 3.6kV ~40.5kV AC metal-enclosed switchgear and controlgear

◇ DL/T486 High-voltage AC disconnect switches and connecting switches

◇ Common technical requirements of DL/T593 standard for high voltage switchgear and controlgear

◇ JB/T 8144.2 Basic Technical Requirements for Power Cable Accessories with Rated Voltage of 26/35kV and Below: Cable Termination Heads

◇ JB/T 8144.1 General Technical Requirements for Basic Technical Requirements of Power Cable Accessories with Rated Voltage of 26/35kV and Below

 

 

Item	Unit	Circuit Breaker Unit	Load Switch Unit
Rated Voltage	kV	12	12
Rated Frequency	Hz	50	50
Rated Current	A	630	630
1min Power Frequency Withstand Voltage	To earth, between phases	kV	42	42
	Across open contacts	kV	48	48
Lightning Impulse Withstand Voltage	To earth, between phases	kV	75	75
	Across open contacts	kV	85	85
Rated Short-Time Withstand Current & Duration	Main circuit	kA	20/4s	/
	Earthing circuit	kA	17.4/2S	/
Rated Peak Withstand Current	Main circuit	kA	50	/
	Earthing circuit	kA	43.5	/
Rated Short-Circuit Making Current (Peak)	kA	50	50
Rated Short-Circuit Breaking Current	kA	20	/
Rated Short-Circuit Breaking Operations	Times	30	/
Rated Operating Sequence	-	O-0.3S-CO-180S-CO	/
Rated Cable / Line Charging Breaking Test	-	Class C2	/
Single-Phase Earth Fault Breaking Current	kA	17.4	/
Rated Active Load Breaking Current	A	/	630
Rated Closed Loop Breaking Current	A	/	630
Rated Cable Charging Breaking Test	A	/	10
5% Rated Active Load Breaking Current	A	/	31.5
Earthing Switch Operating Cycles	Times	5	5
Loop Resistance	μΩ	≤ 140	≤ 140
Rated Gas Pressure (20℃ Gauge Pressure)	MPa	0.02	0.02
Mechanical Life	Vacuum Switch	Times	10000	/
	Disconnecting Switch	Times	3000	/
	Earthing Switch	Times	3000	/
Protection Level	Enclosure	-	IP4X	IP4X
	Gas Tank	-	IP67	IP67
Operating Power Supply	V	AC220/DC220/DC110/DC48/DC24	AC220/DC220/DC110/DC48/DC24
Rated Annual Leakage Rate	%	≤ 0.1	≤ 0.1
Cabinet Dimensions (Single Circuit)	mm	420 × 822 × 1420	420 × 822 × 1420
Internal Arc Withstand (AFLR)	kA/s	20/0.5	20/0.5
Dry Air Moisture Content	ppm	≤ 150	≤ 150

 

Item	Unit	Vacuum Circuit Breaker	Load Switch Unit
Contact Gap	mm	8 ± 1	/
Contact Overtravel	mm	3.5 ± 1	/
Average Opening Speed (6mm after opening)	m/s	1.2 ± 0.2	/
Average Closing Speed (6mm before closing)	m/s	0.8 ± 0.2	/
Contact Bouncing Time on Closing	ms	≤ 2	/
Three-Phase Closing Synchronism	ms	≤ 2	/
Three-Phase Opening Synchronism	ms	≤ 2	/
Closing Time	ms	30 - 70	≤ 900
Opening Time	ms	18 - 50	/
Phase Center Distance	mm	150 ± 1.5	/
Contact Bouncing Amplitude on Opening	mm	≤ 1.5	/
Contact Over-travel on Opening	mm	≤ 2	/
Rated Contact Pressure	N	1600 ± 160	1100 ± 100

 

Item	Unit	Isolating Switch	Earthing Switch
Rated Voltage	kV	12	/
Rated Frequency	Hz	50	/
Rated Current	A	630	/
1min Power Frequency Withstand Voltage	To earth, between phases	kV	42
	Across open contacts	kV	48
Lightning Impulse Withstand Voltage	To earth, between phases	kV	75
	Across open contacts	kV	85
Rated Short-Time Withstand Current & Duration	kV	20/4s	/
Rated Peak Withstand Current	kV	50	/
Mechanical Life	Times	3000	/
Contact Pressure	N	160 ± 20	/
Manual Closing Operating Force	N	≤ 200	/
Manual Opening Operating Force	N	≤ 200	/
Static and Moving Contact Gap	mm	≥ 100	100
Phase Center Distance	mm	150 ± 1.5	/
Earthing Switch Closing Synchronism	ms	/	≤ 2

 

 

Independent enclosed air box structure

The medium-voltage live parts are installed in a closed stainless steel enclosure with an IP67 protection rating, which absolutely guarantees the personal safety of operators; it is not affected by small animals, corrosive gases, humidity, condensation, dust and sunlight, and will not rust or cause eddy currents (the cabinet is made of 304 stainless steel).

 

1. Dry air insulation

Using dry air as the insulating medium makes the product more environmentally friendly, eliminating the use of SF6 gas and its pollution to the environment. The medium-pressure part inside the gas box adopts a composite insulation structure, which is compact, small in size, safe and reliable, and practical.

2. Design of a small vacuum interrupter

The miniaturized vacuum interrupter chamber structure, which uses vacuum as the arc-extinguishing medium and features low contact pressure, reduces the closing output power of the operating mechanism, improves the operational reliability and mechanical life of the switchgear, and truly achieves 10,000 maintenance-free cycles.

3. High level of personal safety

The switchgear adopts a fully insulated and fully sealed structure design, with the enclosure protection level reaching IP4X and the medium-voltage live parts protection level reaching IP67. The switchgear and transmission cables are connected with touchable, fully shielded pluggable cable heads. It has a reliable pressure relief device and mechanical and electrical "five-proof" interlocking. The human-machine interface is well-maintained to prevent misoperation and ensure the personal safety of operators.

4. Spacious cable connection room

The cable connection compartment has a large connection space, suitable for parallel cable connections and additional surge arrester cable connection plugs at the same height. Cables can be installed parallel to each other. The center of the cable outlet bushing is 650mm from the bottom of the box.

5. Flexible expansion methods

Top- or side-mounted electrical connectors can be designed between the functional units to reliably connect with other functional units and facilitate expansion.

6. Each functional unit can be designed as a unit or a shared enclosure, with a maximum of 4 units per enclosure.

 

 

1. Outer shell

The overall structure is bolted together and is made of high-quality steel plate or aluminum-zinc coated steel plate.

The upper part of the outer casing is the secondary instrument compartment, the middle part is the switch operating mechanism compartment, and the lower part is the cable compartment. The lower part of the cable compartment has a cable inlet and a sealed bottom sealing plate. The cable compartment door is a pull-type door, which is simple and convenient to operate and is mechanically interlocked with the switch operating mechanism.

 

2. Air box

The switch operating mechanism, gas pressure gauge, cable inlet and outlet sleeves, and pressure relief device are made of high-quality 304 stainless steel plate and welded and processed, and are arranged on the gas box.

 

3. Pressure relief device

The pressure relief device is installed at the bottom of the gas chamber. When the pressure inside the gas chamber rises abnormally and exceeds the predetermined value, the pressure relief device will be activated to release the pressure, prevent the accident from escalating, and protect the safety of personnel and equipment.

 

4. Operating mechanism

The operating mechanism is installed in the compartment outside the switch room. The disconnect switch and grounding switch use independent three-position operating mechanisms; a mechanical interlock is installed between the two operating handholes to prevent misoperation.

 

Standard Cabinet-type Structure (Upper Isolation & Upper Earthing Scheme)

 

 

Internal Structure of Standard Cabinet-type (Upper Isolation & Upper Earthing Scheme)

 

 

 

 

 

 

This switchgear uses a spring operating mechanism. Both the circuit breaker unit mechanism and the load switch unit mechanism can be operated electrically or manually. The three-position manual operating mechanism is used for the isolating switch and the earthing switch. The circuit breaker operating mechanism has an energy storage function, whereas the load switch operating mechanism closes directly without pre-charging. Typically, the circuit breaker mechanism or load switch mechanism is installed on the same mounting plate as the three-position mechanism (isolating switch and earthing switch) and features reliable mechanical and electrical interlocking. They can also be installed separately, but in that case, the interlocking system would need to be custom-designed.

 

 

 

 

 

Main Technical Parameters for Circuit Breaker Unit or Load Switch Unit Mechanism

Item	Unit	Data
Motor Energy Storage Voltage	V	AC220/DC220/DC110/DC48/DC24
Coil Operating Voltage (Closing / Opening)	V	AC220/DC220/DC110/DC48/DC24
Overcurrent Trip Current	A	5 / 3.8
Secondary Circuit Power Frequency Withstand Voltage	V	2500
Mechanism Output Angle	°	19°
Mechanism Output Closing Work (Torque)	J	65 / 50
Mechanism Oil Buffering Stroke	mm	13

 

Main Technical Parameters for Isolating & Earthing Three-Position Mechanism

Item	Unit	Data
Mechanism Output Angle (Isolating / Earthing)	°	65° / 55°

 

Selection Instructions for Operating Mechanisms
① Please specify the mechanism model.
② Please specify the operating voltages for energy storage, closing, and opening.
③ Please specify whether an overcurrent trip coil is required and its trip current value.
④ For any special requirements, please contact our company's technical personnel.

 

 

 

 

Transportation and Loading/Unloading

 

 

Acceptance and Storage

 

 

Installation

 

 

 

1.Daily Inspection: The patrol inspection cycle of the RMU is determined by the user based on actual conditions.

lCheck whether the RMU shell is damaged.

lCheck whether the load switch positions are correct.

lCheck whether the indicator lights and live line indicators are correct.

lCheck whether the gas pressure is within the specified range.

lCheck whether the RMU grounding is in good condition.

lCheck whether the RMU foundation is sunken or uneven.

 

■ Regular Maintenance:

Under normal conditions, the maintenance and servicing cycle of the switchgear is generally three years. Specific maintenance measures should be carried out as follows:

According to the installation and use manual, tighten all electrical connections (cables, meters, etc.).

Use a vacuum cleaner to clean all components (operating mechanism, cable compartment, meter compartment, etc.) for visual inspection.

Perform one closing/opening operation on all switches, including the earthing switch.

Clean the cable compartment.

For accumulated dust and greasy dirt, a cloth dampened with a small amount of alkaline cleaner can be used. Rinse clean with clean water, and finally wipe the surface dry with a dry cloth.

Acceptance requirements: All components should be intact without obvious discharge traces or damage to connection joints, and no obvious overheating traces at the contact surfaces. If any non-compliant components are found, they should be replaced.

 

 

The following materials and accessories are provided with the product at the time of delivery (valid for unit cabinets or mechanisms):

• Product installation and operation manual.
• Product factory test report and certificate of conformity.
• Packing list.
• Operating handle.
• Keys.

 

 

• Users Main circuit wiring scheme number, main circuit diagram, layout diagram, and plane layout diagram.
• Secondary circuit schematic diagram.
• Models, specifications, quantities, and drilling diagrams of all electrical components in the switchgear cabinet.
• Summary of electrical equipment.
• If the switchgear is used under special environmental conditions, please specify.
• If other accessories, extra components, or spare parts are required, please specify the types and quantities.