8DJH Power distribution equipment

8DJH switchgear is a factory-assembled, type-tested,3-pole metal-enclosed single-busbar switchgear for indoor installation.

8DJH switchgear is used in public and industrial energy systems of the secondary distribution level, e.g. in

• Localring-main units, customer transfer substations and  switching substations of power supply and public utilities
• Windpower and solarplants, hydroelectric power plants
• Water andsewage treatmentplants
• Airports,railway stations,underground railway stations
• Open-cast mining facilities
• High-risebuildings. 

Environmental independence
Hermetically tight, welded switchgear vessels made of stainless steel as well as single-pole solid insulation make   the parts of the primary circuit under high voltage of 8DJH switchgear

– Saline air

– Air humidity

– Dust

– Condensation

• Tightto ingress of foreign objects, such as:

– Dust

– Pollution

– Small animals

– Humidity.

Compact design

Thanks to the use of SF6  insulation, compact dimensions are possible. Thus:

• Existing switchgearrooms and substation rooms can be used effectively
• New constructions costlittle
• Costly city-area spaceis saved.

Maintenance-free design

Switchgear vessels designed as sealed pressure systems, maintenance-free switching devices and enclosed cable  plugs ensure:

• Maximum supplyreliability
• Personnelsafety
• Sealed-for-lifedesign according to IEC 62271-200 (sealed pressure system)
• Installation, operation, extension andreplacement without SF6 gas work
• Reducedoperating costs
• Cost-efficient investment
• Nomaintenance cycles.

Innovation

The use of digital secondary systems and combined protec- tion and control devices ensures:

• Clear integration inprocess control systems
• Flexible andhighly simplified adaptation to new system conditions and thus cost-efficient operation.

Service life

Under normal operating conditions, the expected service life   of gas-insulated switchgear 8DJH is at least 35 years, probably 40 to 50 years, taking the tightness of the hermetically weld-   ed switchgear vessel into account. The service life is limited by the maximum number of operating cycles of the switchgear    devices installed:

• For circuit-breakers, according to the endurance classdefined in IEC 62271-100
• Forthree-position disconnectors and earthing switches,

according to the endurance class defined in IEC 62271-102

• Forthree-position switch-disconnectors and earthing switches, according to the endurance class defined in IEC 62271-103.

Personal safety

• • Safe-to-touch andhermetically sealed primary enclosure
  • Standarddegree of protection IP 65 for all high-voltage  parts of the primary circuit, at least IP 2X for the switch- gear enclosure according to IEC 60529 and VDE 0470-1
  • Cableterminations, busbars and voltage transformers    are surrounded by earthed layers. All high-voltage parts including the cable terminations, busbars and voltage    transformers are metal-enclosed
  • Operatingmechanisms and auxiliary switches safely  accessible outside the primary enclosure (switchgear vessel)
  • Highresistance to internal arcs by logical mechanical interlocks and tested switchgear enclosure
  • Panelstested for resistance to internal faults up to 21 kA
  • Capacitive voltage detecting system to verify safeisolation from supply
  • Dueto the system design, operation is only possible with closed switchgear enclosure
  • Logicalmechanical interlocks prevent maloperation
  • HVHRC fuses and cable sealingends are only accessible when outgoing feeders are earthed
  • Feederearthing via make-proof earthing switches.

Security of operation

• Hermetically sealedprimary enclosure independent of environmental effects (pollution, humidity and small   animals)
• Weldedswitchgear vessels, sealed for life
• Maintenance-free in an indoorenvironment (IEC 62271-1 and VDE 0671-1)
• Operatingmechanisms of switching devices accessible outside the primary enclosure (switchgear vessel)
• Metal-coated, plug-in inductive voltage transformersmounted outside the SF6 switchgear vessel
• Current transformers asring-core current transformers mounted outside the SF6 switchgear vessel
• Complete switchgear interlocking system withlogical mechanical interlocks
• Mechanicalposition indicators integrated in the mimic diagram
• Minimumfi re load
• Option:Resistance against earthquakes.

Reliability

• Typeand routine-tested
• Standardized andmanufactured using numerically controlled machines
• Quality assurancein accordance with DIN EN ISO 9001
• Morethan 500,000 switchgear panels of Siemens in operation worldwide for many years.

General

• • Three-poleprimary enclosure, metal-enclosed
  • Weldedswitchgear vessel without seals, made of stain-   less steel, with welded-in bushings for electrical connec- tions and mechanical components
  • Insulatinggas SF6  (fluorinated greenhouse gas)
  • Maintenance-free componentsunder normal ambient conditions according to IEC 62271-1 and VDE 0671-1
  • Three-position switch-disconnector withload-break function and make-proof earthing function
  • Vacuumcircuit-breaker
  • Cable connection with outside-coneplug-in system

– In ring-main and circuit-breaker feeders with bolted contact (M16)

– In transformer feeders with plug-in contact or optionally with bolted contact (M16)

• Wall-standing or free-standing arrangement
• Pressurerelief downwards, optionally to the rear or upwards via pressure absorber systems.

Interlocks

• According toIEC 62271-200 and VDE 0671-200
• Logicalmechanical interlocks prevent maloperation
• Logicalmechanical interlocks and the constructive

features of the three-position switches prevent mal-   operation as well as access to the cable connection of the feeders and HV HRC fuses under voltage

• Impermissibleand undesired operations can be prevent-  ed by means of locking devices provided at the switching devices
• A detailed description of allinterlocking options is available on page 51.

Insulating system

• Switchgearvessel filled with SF6 gas
• Features ofSF6  gas:

– Non-toxic

– Odorless and colorless

– Non-inflammable

– Chemically neutral

– Heavier than air

– Electronegative (high-quality insulator)

– Global Warming Potential GWP = 22,800

• Pressure of SF6gas in the switchgear vessel (absolute values at 20 °C):

– Rated filling level: 150 kPa

– Design pressure: 180 kPa

– Design temperature of the SF6 gas: 80 °C

– Operating pressure of bursting disc: ≥ 300 kPa

– Bursting pressure: ≥ 550 kPa

– Gas leakage rate: < 0.1 % per year.

Modular design

• Individualpanels and panel blocks can be lined up and extended at will – without gas work on site
• Low-voltage compartment available in 4 overallheights, wiring to the panel via plug connectors.

Panel design

• Factory-assembled, type-tested
• Metal-enclosed, with metallic partitions1)
• Hermetically tight, welded switchgear vesselmade of stainless steel
• Maintenance-free
• Degree ofprotection

– IP 65 for all high-voltage parts of the primary circuit in the gas-insulated panels

– IP 2X for the switchgear enclosure

• Vacuum circuit-breaker with three-position disconnectorfor disconnecting and earthing
• Three-position switch-disconnector
• Cable connection with outside-coneplug-in system according to DIN EN 50181
• Wall-standing arrangement, optionally free-standingarrangement
• Installation andpossible later extension of existing panels without gas work
• Replacement of instrument transformers without gas

work, as they are located outside the gas compartments

• Enclosuremade of sendzimir-galvanized sheet steel,

front cover powder-coated in color “light basic” (SN 700)

• Low-voltage compartmentremovable, plug-in bus wires
• Lateral,metallic wiring ducts for control cables.

Instrument transformers

• Current transformersnot subjected to dielectric stress
• Easyreplacement of current transformers designed as ring-core transformers
• Metal-coated, plug-in voltage transformers.

Vacuum circuit-breaker

• Maintenance-freeunder normal ambient conditions according to IEC 62271-1 and VDE 0671-1
• Norelubrication or readjustment
• Upto 10,000 operating cycles
• Vacuum-tight forlife.

Secondary systems

• Customaryprotection, measuring and control equipment
• Option:Numerical multifunction protection relay with  integrated protection, control, communication, operat- ing and monitoring functions
• Canbe integrated in process control systems.