Degree of Protection | IP65 |
Operating Voltage | 11KV TO 33KV |
Model Name/Number | Breaker AIS panel 11KV to 33KV |
Dimension | refer description |
Type of Control Panel | AIS Panel |
Phase | 3 - Phase |
Emphasis on Operator’s safety by:
MV Air – Insulated Switchgear Range
Medium Voltage family, mirroring all the Construction characteristics of the Standard version
Indoor Type Panels :Available with current ratings upto 4000A and Short Time Ratings of 26.3/40KA. Panel is designed and type tested to meet the requirements of IEC-60298 / IS :3427. Choice of Aluminium and Copper Busbars
Outdoor Type Kiosks :Available with current ratings upto 4000A and Short Time Ratings of 26.3/40/44KA. Panel is designed and type tested to meet the requirements of IEC-60298 & IS :3427. Degree of Protection for enclosure upto IP42 For Indoor and IP55 for Outdoor Applications.
Power Rating | 24 KV |
Number of Phase | Single Phase |
Cooling Type | Oil Cooled |
Winding Material | Mild Steel |
Standards | IEC 62271-202 |
Brand | ABB |
Mounting Type | Din rail |
ABB Compact Secondary Substation , CSS is a prefabricated substation, factory-designed, tested and ready-to-install and is fully compliant with IEC 62271-202 (IEC 61330). Our compact substations are engineered to the highest possible standards for personnel safety and aesthetics, designed to help solve problems of footprint and space limitations experienced within dense urban load centers.
ABB Compact Secondary Substation Salient featuresProduct portfolio
Outdoor CSS for secondary distribution up to 36kV configuration
Outdoor CSS for wind power evacuation at 36kV configuration
Indoor frame mounted CSS for secondary distribution up to 24kV configuration
The enclosure of the outdoor CSS is manufactured using high quality pre-galvanized sheet steel. This provides high resistance to corrosion, which is paramount in outdoor applications. CSS is typically divided into three compartments for – medium voltage switchgear, low voltage switchboard and distribution transformer. The detachable roof with ventilation opening is beam supported and secured at each corner with bolts.
Modular construction
The enclosure’s wall units, roof and doors are constructed using standard modules. Its limiting dimensions are
3830 x 2330 x 2415 mm (L x W x H)
Advantages:
Clinching technology
Self-interlocking modules are inter-connected using clinching technology. All load bearing members are of 2 mm thickness and non-load bearing members are 1.5 mm thick. Bolting is used only for the base frame and lifting fittings.
Brand | ABB |
Feature 1 | Metal-clad, four-sided internal arc-proof construction (IAC AFLR) |
Feature 2 | It is virtually maintenance-free and all circuit breaker operations can be carried out |
Feature 3 | Equipped with multi voltage feeder in direct and alternating current |
Compliance to | IEC 62271-200 |
Mounting | wall |
Unigear type ZVC switchgear : Medium voltage, arc-proof, air-insulated switchgear
Unigear type ZVC switchgear, ABB’s medium voltage air-insulated switchgear, is the result of ABB’s global know-how integrated into a single technological solution and is also ABB’s answer to the range of solutions demanded by global markets. The switchgear complies with IEC 62271-200 standards. ‘Made in ABB’, UniGear comes with the same design and quality standards across 5 continents, and offers the best solutions for all installations including power plants, power distribution substations, compact Motor Control Centers, double-level, duplex and special-unit switchgear.
Salient Features
Apparatus which can be installed in UniGear Switchgear
VACUUM CIRCUIT-BREAKER – CASSETTE VERSION
VACUUM CIRCUIT-BREAKER – FLOOR-ROLLING VERSION
VACUUM CIRCUIT-BREAKER WITH MAGNETIC DRIVE
VACUUM CONTACTORS
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Brand | ABB |
Material | Porcelain |
Automation Grade | Automatic |
Model Name/Number | ZN1 |
Warranty | 1 year |
Feature 1 | Switchgear conforms to IEC 62271-200 |
ABB Unigear type ZN1 – an innovative switchgear for power Distribution requirements
ABB ZN1 primary distribution switchgear is designed to meet the specific needs of the Indian market, with key features such as a compact construction, low maintenance design and an internal arc withstand current rating of 26.3 kA for 1 second that is unique in this sector. The ZN1 range provides an access to the quality, reliability, safety, performance and high level of technical support associated with ABB’s global brand.
ZN1 Switchgear
ABB’s medium voltage switchgear ZN1 contains our knowhow and expertise on air insulated switchgear, and is designed to meet the specific needs of our customers. ZN1
comes with the very best of design and quality built-in to deliver an ideal solution for a wide variety of power distribution needs.
ABB Unigear type ZN1 Key features–– Switchgear conforms to IEC 62271-200
–– Designed for classification LSC2B – PM
–– Designed for fast and easy installation
–– Constructed using aluminium zinc coated steel and pre galvanised sheets making it a highly reliable switchgear
–– Extensible on both sides
–– Encapsulated PTs with built in fuses
–– Cable termination height of 600 mm
–– Factory assembled integral gas duct
–– Simple maintenance
–– Compact and space saving solution with reduced footprints
–– Fitted with conventional instrument transformers
–– Can be offered with ABB’s REF601,REJ601 and other numerical relays for intelligent protection solutions
Safety
–– Internal arc-proof construction conforming to the classification IAC AFLR up to 26.3kA,1 sec
–– Closed door rack-in and rack-out of circuit breaker ensuring full safety to the operating personnel
–– Fitted with standard safety interlocks
–– Provisions of padlocks on shutter, circuit breaker compartment doors, rack in handle insertion
VInd – Vacuum circuit breaker
–– Conforms to IEC 62271-100
–– Floor rolling circuit breaker
–– Continuous rated closing and tripping coils
–– Modular circuit breaker mechanism for fast and easy maintenance
–– Integral spring charging handle
–– Suitable for E2,M2 & C2 (single capacitor bank) class applications
–– In-built mechanical anti-pumping device
ZN1 with single busbar system
Brand | ABB |
Curve Type | DC |
Material | Porcelain |
Automation Grade | Automatic |
Model Name/Number | VD4 G |
compliance to | IEEE/IEC 62271-37-013 standards |
Key features
No. of Poles | 4 |
Rated Current | 4000A |
Brand | ABB |
Curve Type | DC |
Frequency | 50HZ |
Material | Porcelain |
MV indoor circuit breaker : Medium voltage indoor circuit breakers
Vacuum and SF6 gas circuit breaker for safe and reliable electrical power distribution or generation in your application up to 46 kV, 4000 A, 63 kA.
Maximize output and productivity with devices that support the continuous operation of your processes, e.g. three times higher mechanical endurance than the standard.
Protect assets with safe and reliable devices, e.g. generator circuit-breaker type tested to the new global dual logo standard (IEC/IEEE 62271-37-013).
Optimize investments with compact devices and high performance, e.g. 17.5 kV/50 kA circuit breaker with 210 mm pole distance.
ABB’s indoor circuit-breakers have been designed to serve your business needs.
With the wide and globally available portfolio we are able to offer you the right fit for the switching of short-circuit currents, overhead lines and cables under load and no load, transformers and generators, motors, ripple control systems and capacitors – even in parallel.
VD4-CS: one breaker, full control, zero transient Noise-free power quality by safe and reliable switching and protection of capacitor banksVD4-CS is the unique solution based on new vacuum interrupter technology and an innovative actuation systems up to 38kV, 1250A, 31.5kA and with superior noise-free performances, to support your business needs in reactive power compensation
KEY BENEFITS
KEY FEATURES
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compliance to | IEC 62271-200 standards |
Feature | Metal-clad, four-sided internal arc-proof construction (IAC AFLR) |
Feature 2 | LSC-2B with metallic partitions' |
Feature 3 | Constructed with pre-galvanized sheets |
Feature 4 | Earthing-switch is provided as an option |
Applications | Vacuum Interrupters, using radial magnetic field contact system, |
MEDIUM VOLTAGE, ARC-PROOF, UNIGEAR AIR-INSULATED SWITCHGEAR
Unigear Air-insulated switchgear, ABB’s medium voltage air-insulated switchgear, is the result of ABB’s global know-how integrated into a single technological solution and is also ABB’s answer to the range of solutions demanded by global markets. The switchgear complies with IEC 62271-200 standards. ‘Made in ABB’, UniGear comes with the same design and quality standards across 5 continents, and offers the best solutions for all installations including power plants, power distribution substations, compact Motor Control Centers, double-level, duplex and special-unit switchgear.
Salient Features
APPARATUS WHICH CAN BE INSTALLED IN UNIGEA R SWITCHGEAR
VACUUM CIRCUIT-BREAKER – CASSETTE VERSION
VACUUM CIRCUIT-BREAKER – FLOOR-ROLLING VERSION
compliance to | IEC 62271-200 |
Application | installations including power plants, power distribution substations, compact Motor Control Centers |
SALIENT FEATURE | Metal-clad, four-sided internal arc-proof construction (IAC AFLR) |
Feature 1 | Designed in conformance with the highest in class for minimum Loss of Service Continuity - 'LSC-2B w |
Feature | Constructed with pre-galvanized sheets |
Essential Feature | REF542 and other high-end communicable relays |
Unigear with double busbar : Medium voltage, arc-proof, air-insulated switchgear
UniGear-ABB’s medium voltage air-insulated switchgear, is the result of ABB’s global know-how integrated into a single technological solution and is also ABB’s answer to the range of solutions demanded by global markets. The switchgear complies with IEC 62271-200 standards. ‘Made in ABB’, UniGear comes with the same design and quality standards across 5 continents, and offers the best solutions for all installations including power plants, power distribution substations, compact Motor Control Centers, double-level, duplex and special-unit switchgear.
SALIENT FEATURES
Apparatus which can be installed in UniGear Switchgear
VACUUM CIRCUIT-BREAKER – CASSETTE VERSION
VACUUM CIRCUIT-BREAKER – FLOOR-ROLLING VERSION
VACUUM CIRCUIT-BREAKER WITH MAGNETIC DRIVE
VACUUM CONTACTORS
Capacity | 33KV |
Current ratings | 2500A |
Feature | Porcelain Clad Construction, suitable for outdoor sub-station layouts |
Feature 1 | Fully Type Tested |
Feature 2 | Guaranteed for long electrical life |
Feature 3 | Suitable for auto-reclosure duty cycle |
ABB Transformer unit Outdoor Vacuum Circuit Breakers upto 33KV :
Available in current ratings upto 2500A and Short time withstand current of 31.5 KA/3sec. It is designed and type tested to meet requirements of IEC-60056
Salient Features :
– Porcelain Clad Construction, suitable for outdoor sub-station layouts
– Fully Type Tested
– Guaranteed for long electrical life with proven vacuum interrupters and excellent arc quenching and insulating – properties of vacuum
– Guaranteed for long mechanical life
– Minimal operating energy required enabling use of simple, reliable and proven low energy spring operating mechanism Re-strike free
– Suitable for auto-reclosure duty cycle
– Mechanical Operation counter
– Easy to install-structure mounted, with an option to extend structure for mounting of instrument transformer
– Complete breaker can be shipped as one single unit-no adjustment required at site
– Applications-capacitor switching, distribution networks, arc furnace duty, switching unloaded transformers and reactors
Outdoor SF- 6 Circuit Breakers upto 40KV :
Available in a current rating of upto 2500A and STR of 31.5KA / 3sec. It is designed and type tested to meet requirements of IEC-62271-100.
Used in power distribution for controlling and protecting lines, substations and transformer and distribution substations, transformers, rectifier units, capacitor banks etc Thanks to SF-6 AUTOPUFFER breaking technique, they do not generate over voltages and are therefore highly suitable for retrofitting, upgrading and enlarging older installations where the insulating materials of the cables and apparatus may have been stressed during service.
OPERATION
CLOSING-
In the open position, the magnetic actuator’s armature rests against the bottom plate in the actuator assembly. The armature is held there by the force developed by the magnet. When the top coil is energized, the magnetic flux generated is in the same direction as the magnet assembly. The armature is drawn into the coil and brought into contact with the upper plate. In this position, the coil is de energized and the armature is held in position by the magnets alone. As the armature is drawn into the coil, the operating rod, which is attached to the top guide rod, moves the moving contact of the vacuum interrupter towards the closed position. The actuator has more stroke than the vacuum interrupter and the interrupter contacts make contact before the actuator has completed the stroke. The additional movement of the operating rod after the contact closing causes the contact pressure spring to compress at the top of the operating rod. This wipe allows for contact wear in service.
OPENING –
When the bottom coil is energized, the magnetic flux opposes the force generated by the magnet assembly. This reduces the holding force, the armature is released and the coil attracts the armature to the bottom plate. Once there, it is held open by the magnet.
Key benefits
Key features
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No. of Poles | 4 |
Rated Current | 4000A |
Brand | ABB |
Curve Type | DC |
Frequency | 50HZ |
Material | Porcelain |
VM1 indoor circuit breaker Vacuum and SF6 gas circuit breaker for safe and reliable electrical power distribution or generation in your application up to 46 kV, 4000 A, 63 kA.
Maximize output and productivity with devices that support the continuous operation of your processes, e.g. three times higher mechanical endurance than the standard.
Protect assets with safe and reliable devices, e.g. generator circuit-breaker type tested to the new global dual logo standard (IEC/IEEE 62271-37-013).
Optimize investments with compact devices and high performance, e.g. 17.5 kV/50 kA circuit breaker with 210 mm pole distance.
ABB’s indoor circuit-breakers have been designed to serve your business needs.
With the wide and globally available portfolio we are able to offer you the right fit for the switching of short-circuit currents, overhead lines and cables under load and no load, transformers and generators, motors, ripple control systems and capacitors – even in parallel.
IEC indoor vacuum circuit breaker VM1 Extra performances in demanding dutiesVM1 circuit breakers are used in primary power distribution for control and protection of cables, overhead lines, substations, motors, transformers, generators, capacitor banks, etc. in plants in chemical industries, steelworks, automobile industries, airports, large buildings and shopping malls. The magnetic drive activates the moving contacts of the interrupters and integrates all the functions of a traditional drive.
Product scope
Key benefits
Key features
No. of Poles | 4 |
Rated Current | 4000A |
Brand | ABB |
Curve Type | DC |
Frequency | 50HZ |
Degree Of Protection | IP55 |
ABB AIS panels breaker : Medium Voltage family, mirroring all the Construction characteristics of the Standard version
Indoor Type Panels :Available with current ratings upto 4000A and Short Time Ratings of 26.3/40KA. Panel is designed and type tested to meet the requirements of IEC-60298 / IS :3427. Choice of Aluminium and Copper Busbars
Outdoor Type Kiosks :Available with current ratings upto 4000A and Short Time Ratings of 26.3/40KA/44KA. Panel is designed and type tested to meet the requirements of IEC-60298 & IS :3427. Degree of Protection for enclosure upto IP55
No. of Poles | 2 |
Rated Current | 46 kV, 4000 A, 63 kA. |
Brand | ABB |
Material | Porcelain |
Automation Grade | Automatic |
Model Name/Number | ABB SF6 Breaker |
SF6 indoor circuit breaker : Vacuum and SF6 gas circuit breaker for safe and reliable electrical power distribution or generation in your application up to 46 kV, 4000 A, 63 kA.
Maximize output and productivity with devices that support the continuous operation of your processes, e.g. three times higher mechanical endurance than the standard.
Protect assets with safe and reliable devices, e.g. generator circuit-breaker type tested to the new global dual logo standard (IEC/IEEE 62271-37-013).
Optimize investments with compact devices and high performance, e.g. 17.5 kV/50 kA circuit breaker with 210 mm pole distance.
ABB’s indoor circuit-breakers have been designed to serve your business needs.
With the wide and globally available portfolio we are able to offer you the right fit for the switching of short-circuit currents, overhead lines and cables under load and no load, transformers and generators, motors, ripple control systems and capacitors – even in parallel.
SF6 indoor circuit breaker IEC indoor SF6 gas-vacuum multifunction apparatus HySecMaking your solution simpler
HySec comprises the functions of three different devices: circuit breaker, line disconnector and earthing switch. It is ideal for use in medium voltage switchgear for secondary distribution.
Key benefitsKey features
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Rated Voltage | 12kV |
Degree Of Protection | IP54 |
Rated Current | 21kA |
No. Of Poles | 4 |
Brand | ABB |
Material | Porcelein |
ABB SF6 Insulated RMU – SF6 INSULATED RING MAIN UNITS AND COMPACT SWITCHGEAR – SAFERING AND SAFEPLUS FOR SAFE AND RELIABLE POWER DISTRIBUTION
SF6 Insulated Ring Main Units And Compact Switchgear – Safering And Safeplus
ABB offers a complete solution for 12/24 kV distribution networks. This consists of SafeRing, a Ring Main Unit (RMU) that can be supplied in various configurations and SafePlus, a compact switchgear with unique flexibility. SafePlus offers extendibility and fully / semi modular configuration possibilities. Both the units have identical user interfaces. SafeRing / SafePlus are delivered as a completely sealed system with a stainless steel tank containingall the live parts and the switching equipment. Constant atmospheric conditions in the sealed tank ensures a high level of reliability, safety and a virtually maintenance-free system. As an option in SafePlus, an external busbar can be provided to enable a completely modular configuration. SafeRing and SafePlus can also be fitted with a remote control and monitoring unit and are suitable for both indoor and outdoor applications.
ABB SF6 Insulated RMU Key FeaturesStandard Equipment Supplied With Safering / Safeplus
Applications
Safeplus And Safering
Voltage And Short Circuit Indicators
As an option these units can be equipped with fixed type or plug-in type voltage indicators as well as electronic short circuit indicators for simple fault indication.
Circuit breaker with relay
When vacuum circuit breakers are used for transformer protection, self-powered microprocessor based over Current and earth fault relay are used. The protection system does not require an external power supply, as the power is taken from the current transformers.
Power Rating | 25kVA |
Number of Phase | 3-Phase |
Voltage Ratio | 11kV/433V |
Cooling Type | Oil Cooled |
Standards | IS-1180 |
Brand | ABB |
ABB transformers are providing faultless service for over five decades across the world and offer solutions for every need including urban, industrial and rural applications.
In 23 facilities spread across the world, ABB manufactures oil type distribution transformers for indoor and outdoor applications, dry type for reliability and efficiency under critical conditions and transformers for special applications such as for variable speed drives, pad mounted and Booster Transformers
Also available in below power ratings:
10 kVA, 6.35kV/240V 1 phase distribution transformer
630 kVA, 11kV/433V, 3 phase distribution transformer
Brand | ABB |
Winding Material | Mild Steel |
Cooling Type | Dry Type/Air Cooled |
Transformer Type | Dry type transformer |
Phase | Three Phase |
Applications | to increase or decrease currents/voltages. |
Usage/Application | applicable in indoors otherwise outdoors like a commercial, utility, industrial applications. |
ABB dry type transformer is applicable in indoors otherwise outdoors like a commercial, utility, industrial applications. There are various types of electrical devices or components available where some of them operate with the same frequency although the transformer is required for different voltage otherwise current requirements. The main function of a transformer in an electrical circuit is to increase or decrease currents/voltages. There are different types of transformers available in the market but the “Dry Type Transformer” is recommended due to some benefits as inexpensive, more efficient and they have safety features. These transformers also called cast resin type transformers.
IMPORTANT FACTORSThere are many important factors need to consider while designing this type of transformer, they are
In this transformer, insulation breakdown is the most frequently occurred failure which results in severe faults like earth faults or phase-phase winding. Based on the tests only the condition of insulation for the component parts in the transformer like core, windings, and bushings can be determined. In oil type transformer, the condition of winding insulation can be determined by using the common method like dissolved gas analysis but it cannot be achievable in dry-type transformers. There are different tests that include the following.
THE ADVANTAGES ARE
The applications are
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Rated Voltage | 12kV |
Degree Of Protection | IP54 |
Rated Current | 21kA |
No. Of Poles | 4 |
Brand | ABB |
Material | Porcelein |
Rated Current | 1A-5A |
Rated Voltage | 220-240V |
Brand | ABB |
Key benefits | The compact medium voltage vacuum circuit breaker solution for low-duty distribution |
Key features | Modular spring-operated mechanical actuator ensuring easy operation even without auxiliary supply |
Product scope | Medium voltage circuit breakers with lateral mechanical actuator (spring mechanism) for secondary di |
VD4 R circuit breaker : Our product offering covers a wide spectrum of technologies across the entire voltage range including indoor and outdoor circuit breakers, air and gas insulated switchgear, instrument transformers, disconnectors, capacitor banks, reactive power compensators, power and distribution transformers and a range of power distribution products like compact secondary substations (CSS) and ring main units (RMU).
VD4 R circuit breaker Medium voltage indoor circuit breakersVacuum and SF6 gas circuit breaker for safe and reliable electrical power distribution or generation in your application up to 46 kV, 4000 A, 63 kA.
Maximize output and productivity with devices that support the continuous operation of your processes, e.g. three times higher mechanical endurance than the standard.
Protect assets with safe and reliable devices, e.g. generator circuit-breaker type tested to the new global dual logo standard (IEC/IEEE 62271-37-013).
Optimize investments with compact devices and high performance, e.g. 17.5 kV/50 kA circuit breaker with 210 mm pole distance.
ABB’s indoor circuit-breakers have been designed to serve your business needs.
With the wide and globally available portfolio we are able to offer you the right fit for the switching of short-circuit currents, overhead lines and cables under load and no load, transformers and generators, motors, ripple control systems and capacitors – even in parallel.
Reliable low-duty protectionVD4/R circuit breakers with lateral operating mechanisms can be used in all medium voltage secondary distribution systems and MV/LV transformer substations in factories, industrial workshops and in the services sector. Thanks to installation (on request) of the self-supplied PR521 overcurrent release with microprocessor, the VD4/R breakers are suitable for use in unmanned MV/LV transformer substations without auxiliary power supply.
Product scope
Key benefits
Key features
Application | for outdoor installation use sulphur hexafluoride gas (SF6) to extinguish the electric arc |
Fields of application | power distribution for control and protection of lines and for control and protection of transformer |
Routine tests | Temperature rise test |
Routine tests carried | Di-electric test |
Scope of the work | Short circuit test duties |
Work | Mechanical endurance test |
The live tank circuit breaker, OHB medium voltage circuit-breakers for outdoor installation use sulphur hexafluoride gas (SF6) to extinguish the electric arc and as the insulating medium. Breaking in SF6 gas takes place without current chopping or generation of over voltages. These characteristics guarantee a long electrical life for the circuit-breaker and limited dynamic, di-electric and thermal stresses on the installation. The stored energy and free release mechanical operating mechanism allows opening and closing operations through local and remote control. The operating mechanism, the activating kinematics of the moving contacts and the anti-condensation heater are located inside a tight metal enclosure which also acts as the support for the poles.
The above-mentioned structure is supported by a frame made of metal sections, to mount the circuit breaker on foundation. The circuit breaker is compact and ensures a high level of sturdiness and excellent mechanical reliability. The enclosure is made out of a steel plate with adequate surface protection by a special metallizing and painting process. The support structures are hot dip galvanized.
Fields of application
OHB circuit-breakers are used in power distribution for control and protection of lines and for control and protection of transformers, rectifier units, capacitor banks, etc. Due to the SF6 autopuffer breaking technique, the OHB circuit-breakers do not generate overvoltage during switching, and are therefore also highly suitable for retrofitting, upgrading and enlarging older installations where the insulating materials of the cables and apparatus may have already been stressed during service.
Standards and approvals
The OHB circuit-breakers comply with the IEC 62271-100 standard as well as of other major industrialised countries. They have undergone the tests indicated below and
ensure service safety and reliability of the apparatus in all installations.
power distribution for control and protection of lines and for control and protection of transformers, rectifier units, capacitor banks, etc.
– Temperature rise test
– Di-electric test
– Short circuit test duties
– Short time current test
– Mechanical endurance test
Routine tests:
– Power frequency voltage with stand test
– Insulation test on auxiliary and control circuits
– Measurement of main circuit resistance
– Mechanical and electrical operation test
Service safety The mechanical and electrical locking devices have been provided to prevent incorrect operations and to carry out inspection of the installations while guaranteeing maximum
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Rated Voltage | 12kV |
Degree Of Protection | IP54 |
Rated Current | 21kA |
No. Of Poles | 4 |
Usage/Application | SF6 gas insulation |
Brand | ABB |
Material | Porcelein |
ABB Safering 36 RMU , Ring Main Unit (RMU) is a compact, sealed for life metal-enclosed switchgear widely used in Urban Power Distribution Network. . Some of the key features of the RMU includes SF6 gas insulation, compact and modular construction, integral protection system, fully extendable options, and low maintenance.
FEATURES
Ring Main Unit, RMU is a compact, enclosed and sealed type of Switchgear used for medium voltage power distribution. It is a complete Switchgear in itself. A complete Switchgear means, assembly of required switching devices, protection device as well as metering device. RMU of different voltage (mostly 12 kV and 24 kV) and current ratings are available. Indoor as well as outdoor types of Ring Main Units are available.
Ring Main Unit comprises of one incomer feeder and one or more outgoing feeder. The incomer feeder is either Vacuum Circuit Breaker or SF6 Circuit Breaker with associated Disconnect Switch and Earth Switch. This incomer feeder is given with the provision of bushing protruding from the enclosure of RMU for supply cable connection.
Outgoing feeder comprises of Load Break Switches with associated Disconnect Switch and Earth Switch. Provision for cable connection is provided in outgoing feeder. The Load Break Switch is nothing but an isolator having the capability of breaking the circuit during on load condition.