ABB ADVAC - MECHANISM AND OPERATION; Description of EL Operation

1VAL050503-MB Rev B Replaces (1VAL057485-MB Rev. C) Oct 2013
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MECHANISM AND OPERATION
The EL operating mechanism of the Advac circuit breakers (in all versions) is fitted with
a mechanical anti-pumping device which prevents re-closing due to either electrical or
mechanical commands.
Should both the closing command and any one of the opening commands (local or re-
mote) be active at the same time, there would be a continuous succession of opening
and closing operations.
The anti-pumping device avoids this situation, ensuring that each closing operation is
only followed by a single opening operation and that there is no closing operation after
this. To obtain a further closing operation, the closing command must be released and
then re-launched.
Furthermore, the anti-pumping device only allows circuit-breaker closure if the following
conditions are present at the same time:
1. Closing spring fully charged
2. Opening mechanical pushbutton and/or opening release coils (-MO1/-MO2) are not
active.
3. The circuit breaker is in the Open position.
Below is a side internal view of the EL mechanism and the associated anti-pumping component. When the
opening pushbutton or coils are activated the opening shaft lever pushes down on point C of the anti-pump
device. This causes the device to side down slot D in direction of arrow B. Then the trigger portion A moves
out from between the closing push-button and the closing shaft lever. So if the closing button or signal is
held active and the opening button or signal is then activated. The trigger A will pull out from between clos-
ing shaft lever and the closing push button. Once the open signal is released the trigger A will come to
rest under the closing push-button and will not return between the closing shaft lever and closing push-
button until the button or closing command is released.
The closing push button is operated by the closing coil (MC) directly by the shaft closing device. This al-
lows the anti-pumping device to prohibit closing by manual or electrical means.