Isolator


~ as mention above , an isolator is an airbrake type switch that operates on load only.

~ isolator are used in switch yards and substation.

~ for maintenance or short circuit of transformer circuit breaker etc.

~it is necessary to separate it from the live line.

~ the contact of the isolator is kept at a height and can be operated from the ground with a handle like a large stick, so remember that the isolator is an airbrake type switch which should be opened and closed only during no load condition.

~ this is because if the load is on and isolator is open a large are is generated between the two and a fire can break out as well as physical damage to the operator.

~ there is an interlocking between the isolator and the circuit breaker to prevent this type of error.

~ this means that the isolator cannot be opened as long as the circuit breaker is on and the circuit breaker cannot be turned on until the isolator is closed.



                                                          *Types of isolator*   


1) vertical break 

2) horizontal break 

3) vertical pantograph