The specified switchgear is an air-insulated, metal-enclosed and type-tested,   medium-voltage switchgear for indoor installation.

The switchgear must conform to IEC 62271-200, and thus fulfill the following classifications:

• Loss of service continuity category: LSC2B (metallic partitions, i.e. partitioned into separate busbar, switching-device and connection compartments)
  LSC2 for switch-disconnector panels with HV HRC fuses,
  LSC1 for busbar connection panels,
  panels without connection compartment cannot be assigned an LSC category according to IEC 62271-200
• Partition class: PM (metallic partition), PI (shutter made of insulating material) for switch-disconnector panels with HV HRC fuses
• Internal arc classification: IAC A FL (wall standing arrangement)

                             IAC A FLR (free standing arrangement)

The following panel types must be available:

• Circuit-breaker panel
• Bus sectionalizer (bus riser panel with/without withdrawable disconnector link + circuit-breaker panel)
• Metering panel
• Contactor panel (only up to 12 kV)
• Switch disconnector panel with HV HRC fuses
• Busbar current metering panel
• Busbar connection panel
• Disconnecting panel

The switchgear panels shall preferably be designed with panel-type construction.

Requirements for the busbar compartment:

The busbar compartment shall accommodate the three-phase busbars made of round copper profile, the connecting bars and bushing-type insulators with fixed contacts.

It must be possible to open or close the shutter for visual inspection of the fixed contacts individually in the switching-device compartment. The busbars must be bolted together from panel to panel.

The busbars can be accessed by removing steel sheets. Thus, the busbar compartment is a "tool-based" accessible compartment according to IEC 62271-200.

Possible additional components (voltage transformer, earthing switch, bus riser) must be installed in a separate additional compartment.

Requirements for the switching-device compartment:

The switching-device compartment must provide for the installation of the following devices:

• Withdrawable vacuum circuit-breaker
• Withdrawable vacuum contactor (<= 12 kV)
• Withdrawable disconnector link
• Withdrawable metering part

In the door of the switching-device compartment, the mechanical position indicators and control elements of the corresponding switching devices must be visibly integrated in a mimic diagram. In this way, and in connection with the logical mechanical interlocks, any maloperation will be prevented.

While racking from service to disconnected position or vice versa, the shutters covering the fixed contacts in the connection and busbar compartments will be positively opened or closed.

Due to the door interlock, the switching-device compartment has to be designed as an "interlock-controlled" accessible compartment acc. to IEC 62271-200.

The use of maintenance-free vacuum circuit-breakers shall minimize the maintenance and shutdown times. Highly toxic decomposition products as a result of arc extinction in the circuit-breaker are not permissible.

Requirements for the connection compartment:

The connection compartment must contain the following components:

• Cable sealing ends or bar connection
• Current transformers or bushing-type insulators
• Make-proof earthing switch
• Voltage transformers
• Surge arresters
• Earthing busbar
• Zero-sequence current transformer

It must be possible to open or close the shutter for visual inspection of the fixed contacts individually in the switching-device compartment; optionally, it must also be possible to fit a padlock.

The lower shutter is bolted, offering access to the connection compartment from the front during installation.

Cable connection must optionally be possible from the front or from the rear. In case of cable connection from the front, the connection compartment is an "interlock-controlled" accessible compartment according to IEC 62271-200. In case of cable connection from the rear, the access must be designed as "tool-based".

It shall be possible to connect any cable test equipment or cable test adapters without removing the cables. To do this, it must be possible to open and also close the shutters separately. To guarantee personal safety while doing so, the shutters of the busbar compartment must optionally be equipped with a padlock.

Requirements for the low-voltage compartment:

The low-voltage compartments shall be located at the front, completely partitioned from the other parts of the panel, and also be removable from the panel.

The electrical connections between the withdrawable part and the fixed part of the panel shall be established via flexible wires and a 64-pole low-voltage plug-connector.

The current transformer leads must be screwed onto terminals in the low-voltage compartment. All other panel-internal cables are wired to 10-pole connectors and plugged inside the low-voltage compartment.

Bus wires are laid from panel to panel in the upper area of the low-voltage compartment, and shall be pluggable.

The secondary devices shall be mounted in the door of the low-voltage compartment, and on a mounting plate with DIN-rail system. The cables are laid in wiring ducts with sufficiently dimensioned cross-section.

Interlocks:

The following interlocking conditions according to IEC 62271-200 resp. VDE 0671-200 must be fulfilled:

• Feeder earthing switch can only be operated with switching device in disconnected position
• Switching device can only be racked on the movable part with the associated switching device in OPEN position and with feeder earthing switch OPEN
• Switching device can only be operated in interlocked disconnected or service position
• Switching device can only be closed in interlocked service position with the low-voltage connector plugged in

Beyond the specifications of the standards:

• Withdrawable part can only be racked with closed high-voltage door
• Coding prevents insertion of switching devices with a lower rated continuous current into panels with a higher rated continuous current
• Optionally, electromagnetic interlocks, padlocks, or key systems

The safety of operating personnel must be guaranteed by the a.m. interlocks and operations.

The circuit-breaker and make-proof earthing switch must be type-tested in the panel according to IEC 62271-200.