Whuch type of isolator wil you prefer for power systems
Answers
The isolators depend upon the type and capacity of lines/location at which the substation is present. An isolator is just a disconnecting switch. So there are less complexities involved when increasing the voltage range (since the isolator unlike circuit breakers do not quench the arcing). Moreover these operate in off-load conditions - when the currents are zero.
Depending on the line voltages - there may be low voltage(upto 11 kV), medium voltage(11kV to 66kV), high voltage (66kV to 330 kV) , extra high voltage (above 330 kV) lines which require different isolator designs.
With the advent of sophisticated circuit breakers capable of isolating high power lines, use isolators is reduced to lower power lines where the need of isolation is not sufficiently met alone by circuit breakers.