DR-GTXGN-12 Solid Insulation Ring Main Unit

Product structure

Working principle

Solid insulated ring main unit structure features

◆Vacuum arc-extinguishing chamber

The vacuum circuit breaker has the capability to break short-circuit current,is ued for circuit and electrical equipment overload and short-circuit protection.

Owing to its little contact breaking distance, short arc-burning time, slight burn of contact breaking fault current, little actuation energy required, fast reaction and so on, as well as the advantages such as being compact,light, little maintenance,fireproof, explosion-proof and little operation noise, it is ideal to replace the oil circuit breaker and the SF6 circuit breaker,and is widely used in the high-frequency heating and other power distribution systems of electric power,metallurgy, communication and so on. The vacuum arc-extinguishing chamber of the circuit breaker is a key component of vacuum circuit breaker, is the heart of the vacuum circuit breaker, and it basically determines the main performance of circuit breaker.

◆Solid insulated system

The solid sealed pole molded by APG process encapsulates the current-carrying conductors of the vacuum arc-extinguishing chamber, upper and lower outgoing seats into a whole unit. The insulation switch is installed in the cavity of the sealed pole to make the solid insulation the main insulation method for phase-to-phase insulation. The single-phase insulation bus design prevents any serious phase:to-phase or phase-to-ground fault. The bus is expandable for unlimited expansion of functional units.

◆Three-position knife gate

All switchgears are equipped with three-position knife gates. The three-position knife gate and the main switch are built in the solid sealed pole. Operate the three-phase into three positions such as closing/insulation/grounding. The main switch adopts mechanical interlocking and the three-position knife gate only can act when the main switch breaks.

◆Actuator

The actuator of the circuit breaker is a spring actuator with a simple structure and reliable action, is compact and free from maintenance, etc.; the closing power is adjustable as required by the user and it can store energy manually, close manually, break manually, or store energy electrically, break or close electrically, to make it convenient for a user to operate.

The three-position knife gate actuator has a spring in design, can break or close quickly, with the function to break and close a certain load current, the three-position actuator can be actuated manually or electrically for intelligent remote control of insulation and grounding to make it easy to use.

◆Structural characteristics of solid insulated ring main unit

◇The high-voltage load switch and high-voltage live part are sealed in the epoxy plastic insulation bushing shell without any gas, and the vacuum arc-extinguishing chamber is small and reliable in extinguishing arc, The load switch has a grounding switch with three positions such as closing, breaking and grounding, and the grounding knife has the function of an isolation knife.

◇Can combine randomly, each circuit unit outgoes through three high-voltage bushings and it’s convenient to connect a cable.

◇With an imported sealed enclosure,the actuator's terminals and high-voltage bushings are strictly sealed with good performance.

◇The high-voltage bushing and high-voltage insulation cylinder are made of imported epoxy resin by APG process, and the insulation cylinder and high-voltage bushing are assembled tightly by silicon rubber sleeve, with good seal performance.

◇Each circuit is equipped with an independent actuator that is installed in the front of the cabinet with several mechanical interlocking functions.

◇The load switch and grounding switch are equipped with spring actuators, and the load switch can be actuated manually or electrically, The grounding switch can ground or insulate, only can be actuated manually.

◇The circuit breaker can be equipped with a permanent-magnetic actuator, can close or break electrically, can break manually, can’t close manually.

The circuit breaker can also be equipped with a spring actuator; can be actuated manually or electrically, with power distribution automation interface reserved.

◇The ring main unit panel has a view window, can directly observe the insulation knife’s breaking or closing with an obvious breaking.

◇Each ring main unit has three independent insulation cylinders in parallel,it' s easy to install, with the biggest advantage to prevent the phase-to-phase electrical discharge.

◇ The main parts of the solid insulated enclosed ring main unit are composed of the insulation cylinder and vacuum arc-extinguishing chamber.

◇The solid insulation material is imported epoxy plastic resin with a thickness no less than 10mm and a strong insulation capacity, is highly resistant to corrosion, the internal space is more than 150mm, two phases are separated and combined by base plate bracket, it's flexible, easy and reasonable to combine a structure with a good look.

◇ The enclosure has a sealed floor for cable incoming to prevent the moisture in the cable trench from entering the enclosure.

◇The door is sealed with seal strips, the door lock is in a rainproof structure,it’s easy to fix the door when open with limit lever.

◇The switches in the enclosure are solid insulated and sealed and a heater isn’t required, and the cable gland can be touchable and non-touchable as required by the user,without worry for water immersion.

◆Actuator and operation

◇The load switches and grounding switches in the ring main unit are equipped with independent spring actuators, which are installed in the front of the panel, can be actuated manually or electrically. With two operation holes for each circuit of the panel, to actuate the load switch and grounding switch.

The vacuum circuit breaker is equipped with a combined permanent-magnetic actuator or a spring actuator.

◇Load switch operation

Feed power

First close the grounding switch: insert handle into the grounding hole (when the insulation knife is in grounding),rotate counterclockwise to break, and insert the handle into the insulation hole, rotate counterclockwise to close the insulation knife.

Reclose load switch: insert the handle into the main switch hole, rotate 2 circles counterclockwise to close the main switch.

Cut power

First break the load switch: rotate the breaking knob counterclockwise to break the switch.

Then break the insulation grounding switch:insert the handle into the insulator hole, rotate clockwise to break the insulation knife, then insert the handle into the grounding hole and rotate clockwise to close grounding.

◇Circuit breaker operation

◇Mechanical interlocking: With mechanical interlocking between load switch, circuit breaker and grounding switch. When the load switch and circuit breaker are closed, the grounding switch can’t break or close: when the grounding switch is closed, the load switch and circuit breaker can't break or close.

◆Installation and replacement of fuse

◇First close the grounding switch.

◇Lift the handle and rotate counterclockwise to make the pin protrude from the slot.

◇Install the pin mechanism into the fuse drum to make the pin in the slot, rotate clockwise to make the handle parallel to the panel, and then push down the handle with force.

◇Open only when the load switch is grounded.

Load switch -fuse combination electrical cabinet selection table with fuse

Potential transformer capacity kVA	Fuse model	Fuse rated current(A)
		Voltage class 12kV	Voltage class 6.3kV
100	XRNT-12kV	10	16
125	XRNT-12kV	10	20
160	XRNT-12kV	16	20
200	XRNT-12kV	20	25
250	XRNT-12kV	25	31.5
315	XRNT-12kV	31.5	40
400	XRNT-12kV	40	50
500	XRNT-12kV	50	63
630	XRNT-12kV	63	80
800	XRNT-12kV	80	100
1000	XRNT-12kV	100	125
1250	XRNT-12kV	125	-

Standard module-circuit breaker cabinet

Standard configuration                                                                                                                                              

◆630,1250A insulation bus

◆Vacuum circuit breaker

◆Vacuum circuit breaker actuator

◆Insulation/grounding switch

◆Insulation/grounding switch actuator

◆Mechanical interlocking of circuit breaker and grounding switch

◆Circuit breaker and grounding switch have independent position indication

◆Outgoing bushing is horizontal and in the front with a cable gland

◆ The live indicator is combined with the phase check hole according to ISO61958 standard

◆Grounding bus

◆Microcomputer protector

◆With five-protection interlocking

Optional configuration

◆Auxiliary contact.

◆Program lock

◆Heater

◆Back arrester

◆Back cable gland

◆Incoming line live grounding block

◆Grounding fault indicator

◆Bushing current transformer and ammeter,active power meter,reactive power meter

Standard module-load switchgear

Standard configuration                                                                                                                                                                    

◆630A insulation bus                                                                                                                                           

◆Vacuum load switch

◆Vacuum load switch actuator

◆Insulation/grounding switch

◆Insulation/grounding switch actuator

◆Mechanical interlocking of load switch and grounding switch

◆Load switch and grounding switch have independent position indication

◆Outgoing bushing is horizontal and in the front with a cable gland

◆The live indicator is combined with the phase check hole according to ISO61958 standard

◆Grounding bus

◆With five-protection interlocking

Optional configuration

◆Energy storage motor of load switch actuator

◆Breaking coil

◆Closing coil

◆Auxiliary contact

◆Program lock

◆Heater

◆Back arrester

◆Back cable gland

◆Incoming line live grounding block

◆Grounding fault indicator

◆Bushing current transformer and ammeter,active power meter,reactive power meter

Standard module-load switch fuse combined appliance cabinet

Standard configuration                                                                                                                        

◆630A bus

◆Vacuum load switch

◆Vacuum load switch actuator

◆Insulation/grounding switch

◆Insulation/grounding switch actuator

◆Mechanical interlocking of load switch and grounding switch

◆Load switch and grounding switch have independent position indication

◆Outgoing bushing is in the front with cable gland

◆The live indicator is combined with the phase check hole according to ISO61958 standard

◆Horizontal fuse cartridge

◆Fuse

◆Grounding bus

◆With five-protection interlocking

◆Auxiliary grounding device

Optional configuration

◆Energy storage motor of load switch actuator

◆Breaking coil

◆Closing coil

◆Auxiliary contact

◆Program lock

◆Heater

◆Back arrester

◆Back cable gland

◆Incoming line live grounding block

◆Grounding fault indicator

◆Bushing current transformer and ammeter,active power meter,reactive power meter

Standard module - PT cabinet with insulation switch (Full insulation)

Standard configuration                                                                                                                                                       

◆630A insulation bus

◆Insulation grounding switch

◆Insulation grounding switch actuator

◆Insulation/grounding switch

◆Outgoing bushing is horizontal and in the front,630A is connected with cable gland

◆The live indicatoris combined with the phase check hole according to ISO61958 standard

◆Solid insulated potential transformer

◆Elbow connector(with cable)

◆Potential transformer protection fuse

◆Grounding bus

◆With five-protection interlocking

Optional configuration

◆Heater

◆Voltmeter

Standard module -PT cabinet without insulation switch (common)

Standard configuration                                                                                                                                                                                

◆630A insulation bus

◆The live indicator is combined with the phase check hole according to ISO61958 standard

◆Solid insulated potential transformer

◆Elbow connector(with cable)

◆Potential transformer protection fuse

◆Grounding bus

◆With five-protection interlocking

Optional configuration

◆Heater

◆Voltmeter

Standard module -metering cabinet(common)

Standard configuration                                                                                                                              

◆630A,1250A insulation bus

◆Common PT,CT potential transformer,current transformer

◆Potential transformer protection fuse

◆Kilo-watt hour meter

◆The live indicator is combined with the phase check hole

Optional configuration

◆Metering interlocking device

◆Heater

◆Voltmeter

◆Active power meter

◆Reactive power meter

◆Voltage conversion switch

Standard module -insulation switchgear

Standard configuration                                                                                                                                                                                          

◆630A,1250A bus

◆Insulation/grounding switch

◆Insulation/grounding switch actuator

◆Grounding switch has position indication

◆Outgoing bushing is horizontal and in the front,with cable gland

◆ The live indicator is combined with the phase check hole according to ISO61958 standard

◆Grounding bus

◆With five-protection interlocking

Optional configuration

◆Auxiliary contact

◆Heater

◆Back arrester

◆Back cable gland

◆Incoming line live grounding block

◆Grounding fault indicator

◆Bushing current transformer and ammeter,active power meter,reactive power meter

Standard module -upgraded cabinet

Standard configuration                                                                                                                                                                                                          

◆630A,1250A insulation bus

◆Outing bushing is horizontal and in the front,with cable gland (with cable)

◆The live indicator is combined with the phase check hole according to ISO61958 standard

◆Grounding bus

Optional configuration

◆Heater

◆Back arrester

◆Back cable gland

◆Grounding fault indicator

◆Bushing current transformer and ammeter,active power meter,reactive power meter

Foundation plan

◆Installation

The ring main unit shall be installed in a well-ventilated area,to operate and maintain in front,the base of the ring main unit has foot mounting holes;  the indoor cabinet can be installed away from the wall or against the wall,and installation position is in the figure.The flatness of the track laid on the foundation shall not exceed 2mm per square meter.The base of the ring main unit must be fixed onto the foundation.To install outdoor,the foundation must be built on a high ground,and the distance from the wall or shelter around it must not be less than 1 meter to open the door easily.

The walls of the pit are made of cement and solid bricks and the surface is treated to prevent water seepage.The walls of the pit and the foundation are made of 1:2.5 cement mortar with a thickness of 20mm,and the surface must be smooth.The soil mix is made according to GB232-82“Electrical Installation Engineering Construction and Acceptance Specification”.When cables are installed,the cable room bottom plate shall be sealed to prevent moisture from entering the trench.The ring main unit must be connected with the grounding network on site.The grounding of the ring main unit is marked.

Dimensions

Applications

◆Low-temperature cold area:When SF6 gas isn't used,no need to consider the low temperature operation of SF6 gas,it can operate normally at-45°C.

◆Plateau area:No need to consider the effect of plateau atmospheric pressure on insulation performance.

◆Strong-wind and sandy area:Solid-insulated ring main unit safety protection grade is IP67,control circuit room has special treatment to ensure long-term operation in a strong-wind and sandy area.

◆Coastal humid area:Epoxy resin seal is anti-humidity,anti-salt-fog-corrosion to ensure long-term use in a coastal area.

◆An area with high requirements on environmental protection:People have paid great attention to the SF6 gas warming effect on the atmosphere;SF6 gas is cancelled in a solid ring main unit,without pollution and harm to environments and people.

◆In smart power grid:The main switch is electrically actuated;the intelligent controller developed by our company is optional,and it can be used for the remote control,telemetry,telecommunication,

decentralized or centralized control of the switchgears and substations on site.