Withdrawable type switchgear Clausole campione

Withdrawable type switchgear. The switchboards of the main substations, QMT-SS and QMT-G will be provided with withdrawable type switchgear. The switchboards will be equipped with solidly grounded poly carbonate shutters, which shall automatically open when the breaker is racked into the connected position and close (covering the primary contacts and current transformers) when racked to the test or disconnected positions or withdrawn from the cell. Shutter earthing will be by dedicated ground wires. The actuation of the shutters shall be by the movement of the circuit breaker and be padlockable in closed position. The power circuit breakers will be electrically operated, 3-pole, draw-out type, with vacuum interrupters and motorised charging of a spring type stored energy operating mechanism. The power circuit breaker will be provided with self-aligning line-side and load-side disconnecting devices. The breaker racking system will allow smooth, consistent breaker movement with the door closed and will have three positions in addition to the fully withdrawn position; disconnect, test and connected. The circuit breaker will stop and lock in all three positions, requiring operator action to move from one position to another. The circuit breaker will be provided with an integral racking mechanism. The draw-out mechanism will hold the breakers rigidly in the CONNECTED (primaries and secondaries engaged), TEST (primary contacts disconnected and shutter closed, but control contacts engaged) and DISCONNECTED (both primary and secondary contacts disengaged) positions, with the door closed. The secondary contact plug will automatically disconnect when the breaker is moved from the TEST to the DISCONNECTED position. The disconnecting device will be positioned and constructed as to not expose the operator to live parts. Interlocks will be provided in order to prevent connecting the breaker to, or disconnecting it from the bus stabs unless the breaker is OPEN (tripped), assuring proper sequencing and safe operation. The close springs of the circuit breaker will automatically discharge when the breaker is released from the cell by pulling in on the truck latch assembly. The switchgear shall be constructed in accordance with the following main requirements: Description Specification Switchgear type Withdrawable Rated current See drawings Interrupting capacity ≥1000 MVA Circuit breaker interrupting capacity ≥31.5kA (or 20 kA - to be decided during the Projetto esecutivo phase) Busbar Single Breaker clo...