33 KV Outdoor Vacuum Circuit breaker uses Vacuum as the Arc Extinguishing Medium and are Porcelain Clad, so as to provide adequate clearances required for the outdoor application.
It mainly consists of two parts viz.:
1) Pole unit, which consists of three independent poles.
2) Operating mechanism, which have seen operating the moving contacts of the breaker.
The pole consists of the upper part and the lower part. Fix rod is fixed to the upper terminal plate why the moving contact blocked is clamped to the the moving system of the vacuum interrupter.
In it is placed in top part of the breaker Pole.
It is used to Close/Trip the Breaker Locally, that is in the yard. Contacts are Normally Open, few contacts are open in Close Position and few are open in Trip Position.
A Dropping resistor is placed in Tripping and Closing Circuit, in order to match the Auxiliarry Suppy Voltage and the Volatge Rating of the Tripping or the Closing Coil.
Local Remote Switch is a Device used in the Control Circuit of the HV/EHV Circuit Breakers in the Substation. It is used in the Remote Operation (Closing ) of the Circuit Breakers. Need and Working of Local Remote (LR) Switch in Circuit Breakers:
The function of the Local Remote Switch in Circuit Breaker Scheme is to ensure Safety of the Personnel working on the Breaker, while the Breaker is under Maintenance.
Lets say, we are doing Maintenance on the Breaker and someone by mistake gives a Closing Command from the Remote TNC Switch (TNC Switch on the CP/RP), the Breaker will close, which can cause an Accident of the personnel working on the Breaker.
To avoid such kind of Accidents, during Breaker Maintenance, LR Switch is used in the Breaker Closing Control Circuit.
With the use of LR Switch, when the LR switch is in the Local (L) Mode, the Breaker cannot be closed Remotely i.e. through Remote TNC Switch (TNC Switch in the CP/RP).
Instead of giving the DC Positive directly to Local TNC (Breaker TNC) and Remote TNC (CP/RP TNC) , it is given through the Local-Remote (LR) Switch in the Breaker.
So, the Breaker Positive is first given to one end of LR Switch.
If the LR Switch is in Local Mode, the DC Positive is extended to Breaker TNC Switch and
If the LR Switch is in the Remote Mode, the DC Positive is extended to remote TNC Switch (K5).
The Positive coming to the Remote TNC Switch (CP/RP TNC Switch) is called Closing Positive (K5).