High Voltage Ring Main Unit Switchgear

• Customization: Available
• Certification: CCC, ISO9001
• Shell Material: Steel Plate
• Model NO.: SMS6 Ring Main Switchgear 630A
• Voltage Level: Medium Voltage
• Installation: Fixed
• Structure: Cabinet
• Current: AC
• Transport Package: Plywood Packaging
• Specification: 500*920*1800
• Trademark: SHME
• Origin: China
• HS Code: 8538109000
• Production Capacity: 1000 Set/Year

Product Description

SMS6 Ring Main Switchgear
Switch SF6-Insulated
Metal-Enclosed Switchgear
Up to 40.5KV

GENERNAL DESCRIPTION
Complete Medium Voltage Switchgear Solutions
SANHUA is a pioneer in the design and manufacture of power distribution and protection equipment for the electrical industry, offering a comprehensive range of medium voltage (MV) solutions to meet the needs of virtually any application.

EXCELLENT EXPERIENCE:
SMS6 Ring Main Switchgear provides users with a variety of excellent experience with its Smooth operation, exemplary availability and optimal safety.

FLEXIBLE and CUSTOMIZABLE
SMS6 Ring Main Switchgear modular construction of the range allows SANHUA Engineering's team of expert engineers to customise each medium voltage power solution based on individual project specification.

MODULAR DESIGN CONCEPT
The SMS6 Ring Main Switchgear system is a modular concept based on the "building blocks" principle, which means that cubicles are produced in series. As a result, the modular SMP concept meets the highest technical standards in a rational, economically sound way. The combination of cubicles is unlimited. Very complex diagrams of distribution and transformer switchgear can be compiled through this extensive spectrum of possibilities. The semi-compact cubicles are particularly beneficial if the available space should pose a problem or if economical factors play an important role. Compartments also contain all functional interlocks which allows for effortless application, according to all current standards, and which allows installation in consumer work spaces. As a result, capacity loss will be minimal. Additionally, the compartments have been fitted with a system for pressure release which shields the user from the consequences of an internal arc.



Performance Characteristics
Main advantages
SHME SMS6 Switchgear is simple and easy to use. Detailed logotype and single line diagram on the front, with compact dimensions and intuitive mnemonic names.

Operational Safety
Operator safety is ensured by the following measures:
- Multi-stage system with built-in interlocks (electromagnetic, mechanical)
- Three-position design of gas-insulated switchgear
- Design solutions that meet all requirements of global electrical safety standards.

Application versatility
Excellent individual functionalization ensures freedom of choice of technical solutions for each specific facility. Load break switches with SF6 insulation and fuse protection, vacuum circuit breakers with microprocessor relay protection and automation units can play an important role in both simple substations and distribution systems with complex distribution schemes.

High Reliability
Using SF6 arc extinguishing medium can significantly extend the switching life of the load switch. Design solutions and extensive digital relay protection functions minimize the possibility of failure, repair and maintenance. Coupled with severe production tests, it is also a strong guarantee for high reliability.

Small Size
Due to the small size, the construction cost of the new project plant is significantly reduced. In addition, the small size of the units made it possible to modernize the existing project plant without increasing the site area. Due to the small size, the power distribution system can be arranged flexibly and the cost of power transmission can be significantly saved.

Easy To Maintain
SMS6 switchgear requires minimal maintenance during operation. The equipment in the unit is technically retractable or extractable, all controls are located on the front panel, and the status of the equipment is displayed on mechanical and lighting mnemonic diagrams. Modern digital protection relays are equipped with self-diagnostic systems. The power distribution cabinet system is designed with a complete early warning system, and any status and parameters can be easily and intuitively read and analyzed

Remote Control and Data Acquisition
Parameterization of power systems, oscillograms of fault events, remote control of circuit breakers, etc. can be performed quickly and reliably by using modern microprocessor-based relay protection units. The fast and reliable communication design enables the SMS6 switchgear to be reliably integrated into the automatic control and metering systems of electric power, as well as SCADA systems.

Quality Assurance
Sophisticated manufacturing equipment, strict quality control, precise inspection system and perfect production process make it possible to significantly increase the service life of SMS6 switchgear.
 

SHME SMS6 Switchgear Technical Parameter
NO.	Name	Unit	Detail
1	Rated	KV	12
2	Rayed Frequence	HZ	50
3	Main Busbar Current/Fuse Current	A	630/125
4	Main loop/ground loop rated short-time withstand current	KA/S	20,3
5	Main loop/ground loop rated peak withstand current	KA	50
6	Main circuit/ground circuit rated short-circuit making current	KA	50
7	Load switch full capacity breaking times	Time	100
8	Fuse breaking current	KA	31.5
9	Rated closed-loop breaking current	A	630
10	Rated transfer current	A	1600
11	Mechanical life	Time	2000
12	1min power frequency withstand voltage (peak) phase To phase	KV	42
13	1min power frequency withstand voltage (peak) phase To Ground(isolation fracture)	KV	48
14	Lightning impulse withstand voltage (peak) phase-to-phase	KV	75
15	Lightning impulse withstand voltage (peak) phase-to- Ground(isolation fracture)	KV	85
16	1min power frequency withstand voltage of secondary circuit	KV	0.6
17	Protection class		IP3X

Introduction to Each Part of Switchgeart
Frame:
SMS6 switchgear is a cabinet made of ≥2mm thick aluminum-zinc plate. The main structure is manufactured by cold stamping on high precision CNC equipment. All connections of load-bearing structural elements are made on rebar rivets. The front structural elements (doors, side panels, etc.) are phosphating, and the surface is also coated with RAL7032 powder coating (color can be selected), which has excellent corrosion resistance.

Compartment
To guarantee high positioning capability and operational safety, the SMS6 switchgear is divided into the following compartments:
- busbar compartment
- protective relays and low voltage compartments;
- Measuring equipment and cable connection compartment

Interlock
The interlocking device installed in the SMS6 switchgear meets the requirements of IEC and GB standards.
A high degree of operator safety is of paramount importance in the design of switchgear. The SMS6 switchgear is equipped with a complete interlocking device to prevent misoperations that could endanger switchgear operators and maintenance personnel. The SMS6 switchgear is designed with a number of mechanical safety interlocks, which can also be supplemented by complementary electromechanical interlocks.
- Prevent mis-opening (closing) SF6 load switch
- Prevents closing or opening isolating switches and isolating contacts with load
- Prevents live closing of earthing switches
- Prevent power transmission when the grounding switch is closed
- Prevents accidental entry into compartments which have electricity

Operational Safety
The doors of the high voltage compartment are equipped with mechanical and electromagnetic interlocks.
On the front of the power distribution cabinet, each load-break switch, isolating switch, grounding switch and control device has a clear location index mark. On the front of the relay protection room door there is a main wiring simulation diagram showing the position of the switchgear by light indication: open, closed or grounded.
At the top or rear of the switchgear, there is an opening for pressure relief to prevent structural damage and product ejection in the event of a load circuit fire. The opening for pressure relief is normally closed and fixed with special bolts. Under a certain safe pressure, this special bolt will break to ensure the release of pressure and ensure the safety of the switchgear and its surroundings. For the internal lighting of the main body of the switchgear, LED lighting is used, which does not need to be replaced during the entire operation. All equipment, instruments and structures installed in the power distribution room must comply with solid grounding and grounding.

Busbar Compartment
Insulated busbar compartments significantly improve reliability and eliminate the possibility of overlapping within the switchgear. The bus bars are formed by connecting copper bars in series with each other. The busbar is installed on the terminals of the fixed contacts of the isolating switch or load switch. Using bolts and washers with a strength class of 8.8, the busbars of the switchgear are maintenance-free during the entire operation, provided that the bolted connection has a suitable tightening force during the installation of the equipment, for which we use torque wrench when tightening the bolts.
To localize the arc within a unit, there is an option to install bulkheads with busbar bushings in the busbar compartment.
For two rows of units in a room to be arranged in parallel, the switchgear can be interconnected via bus bridges or cable inserts.

Low Voltage Compartment
In the low-voltage compartment, protective relays, commercial or technical electricity metering devices, electrical measuring instruments (ammeters, voltmeters), terminal blocks, heating, lighting, automation and operation interlocking circuits are installed. Furthermore, if an automatic control system (ACS) is introduced into the switchgear, all necessary components are installed in the low voltage compartment.
To connect the auxiliary circuits of the switchgears, these lines are laid in cable channels built into the low-voltage compartment of each switchgear.
We can install protection devices and components from different countries according to the needs and habits of users.

Simulation Diagram
In each SMS6 switchgear, in order to inform the operating and maintenance personnel of the position status of the switchgear, a Simulation diagram with light indication is used, which is located on the door at eye level.

Current Transformer
The current transformers are all sealed, and have undergone many tests such as withstand voltage, accuracy, thermal stability, etc. before leaving the factory. Each transformer has its own test report, which is directly delivered to the user following the product. All tests for current transformers are carried out according to IEC and GB standards.

Voltage indicator
Use a voltage indicating unit to monitor the presence of voltage on connecting cable lines and busbars, The voltage indicating unit receives a signal from a capacitive voltage divider which mounted inside the support insulator. The voltage indicating unit is placed on the front panel of the power distribution cabinet, so that the phase sequence of the cable line can be detected by the phase sequence detection device under low voltage.

Door Structure
Compartment doors have reinforced structures and mechanisms that ensure they are secured to the switchgear at multiple points when the door is closed.



Front Cable Connection (optional)
In SMS6 switchgears, to significantly simplify the installation of power cables, the possibility of frontal connection is provided. This is especially true when using cables with large cross-sections (500-630mm²).

Protection Relay
According to customer requirements, the domestic or foreign microprocessor relay protection unit can be integrated into the secondary circuit of the SMS6 switchgear. The experience of the developers of SHME and the availability of a large number of standard solutions made it possible to carry out this work in the shortest possible time.

Arc protection
According to user requirements, modern arc protection devices based on fiber optic sensors can be installed.
Arc protection works on the principle that the switch is closed when a flash from an arc discharge is received at the fiber optic sensor and there is a signal from an activation relay unit. Depending on the selected mode, selective and non-selective shutdown can be performed. In the case of selective shutdown, the central unit issues a command to close only the damaged circuit, in the case of non-selective shutdown, the inputs and partial switches are closed, and the auto-recloser and auto-backup inputs are disabled.



Voltage transformer
Voltage transformers are designed to convert the voltage of the main circuit to the level of measuring instruments, relay protection, automation devices, control, power metering circuits.

Zero sequence current transformer
Zero sequence current transformers are designed to detect earth leakage currents.
Connect the secondary winding of the zero-sequence current transformer to the corresponding analog input of the relay protection and automation unit, and the zero-sequence current transformer is installed at the bottom of the distribution cabinet itself.

Disconnectors and SF6 Insulation Disconnectors
In the SMS6 switchgear, the switch with SF6 insulation is installed:
Design Features
- First of all, the design feature is that the contact system is completely isolated from the environment, and the arc in the insulating environment is reliably extinguished by sf6    gas.
- The design of the switchgear precludes the simultaneous execution of both "ON" and "Ground" switching operations, thus preventing outgoing wires from being grounded         under voltage. In addition, the design of the unit precludes operator error, increasing operational safety and reducing the possibility of damage to switchgear equipment.
- All devices allow the contact system to stay in three different states for a long time. The design of the load break switch combined with the fuse is such that if at least one of    them blows, all three phases are disconnected. This eliminates the possibility of transformer open-phase operation and increases the safety of service. SMS6 distribution        cabinets are equipped with fuses with mechanical strikers for automatic disengagement according to IEC and GB standards.



Grounding Switch
SMS6 power distribution cabinet can install earthing switch with air insulation according to user requirements

SF6 switch Device
Structurally, the SF6 switchgear has a sealed enclosure, filled with SF6 gas (the mass of SF6 is about 230 grams, and the mass of SF6 varies with different switches), and under a slight overpressure (0.5 atmospheres), all current-carrying of the circuit breaker The components are all located within this housing. All SHME switchgear, regardless of their type (isolator, load break switch) have a common structural arrangement.
The switch housing consists of two parts - the base and the cover, made of epoxy compound by injection moulding.
The housing base includes fixed lower line contacts and ground contacts. The current flows through the conductors and ends at the terminals on the outside of the base, which are used for external busbar connections. There is a threaded hole in the center of the terminal for connecting the current-carrying bus. The rear of the base is made into a trapezoidal channel, which is used as the rear support of the equipment. When a short circuit occurs inside the circuit, it is used as a channel for pressure relief and discharge of arc combustion products. The wall thickness of the partition is chosen such that it will be destroyed when the overpressure of the SF6 gas in the enclosure rises to a dangerous limit. The housing cover acts as a holder for the upper fixed contacts, which are similar in design to the contacts for the lower wiring described above.
Inside the housing there is a main switch contact system of the device, which consists of fixed linear contacts, fixed ground contacts and moving contacts.




How SF6 switch disconnectors work
Pure gaseous SF6 (sulfur hexafluoride) is chemically inert, harmless, non-flammable, non-combustible, has high heat dissipation capacity, and successfully combines insulating and arc-extinguishing properties. The electrical strength of SF6 gas is 2.5 times that of air. Its electrical characteristics are highly stable.
The moving contacts of the load switch are driven by a spring-loaded mechanical actuator located outside the housing and are securely attached to the housing by bolted connections. The mechanical connection of the moving contact to the drive is carried out with the help of a rotating shaft which passes through a sealing assembly located on the body of the device. During most of the rotation of the drive shaft, the mechanical energy builds up in the drive spring, while the moving contacts inside the housing do not move. At some point on the shaft, the fixed end of the spring is released, and the spring expands, causing the moving contact to move at a speed that depends only on the energy accumulated by the spring.
During the breaking operation, the moving contact shaft rotates and the main contacts break. The arc produced in this case is extinguished by the SF6 medium.
When the moving contact is turned, the device can occupy three fixed positions, closing or opening each group of contacts. The applied arc quenching principle, based on the arc rotation technology and the thermal expansion effect of SF6 gas, ensures arc quenching when the rated current (both capacitive and inductive) is switched off.


Anti-condensation heating element
In order to maintain the normal working conditions of the SMS6 switchgear, heating elements (resistors) are installed in the cable room and the relay protection room. The heating temperature is controlled by a thermostat.