11 KV ISOLATOR

Hello Guest,

You have not advised what type of Isolator you are talking about.

In general an Isolator is an "Airbreak switch", with a large visible gap, manually operated when not under load conditions, to ensure easy and safe earthing on the Isolated equipment, preparatory to working on the now earthed safe equipment or line.

There are automatic or manual switchgear, Circuit Breakers, Fuses, Auto-drop-out fuses and so on, which do isolate the line or equipment, but are not regarded as Isolators for the safe working on the line or equipment.

For Safe Isolation, there must be a large visible gap in each phase connection, normally 3 times the "flashover voltage" under high humidity or wet conditions.

Trust that explains the Isolator.

Hope you enjoy learning about the Electrical Systems.

Should you require further information, reply in this Topic Thread, thanks.

Kind Regards....

I think he is asking the type of construction etc. May be Centre Break double pole, pantograph, Single break etc will be his ans.

There are load break switches in 11 kv distribution ( on load and off load )which many manufacturers are providing . They can be used for controlling transformers and distribution systems. There are pole mounted off load air break isolating switches. it is not clear what is your requirement . Please give details about your thread

in 11kv also its known as Isolator only like a motor of 10MW and also 0.05w is always known as motor

Dear Guest,

The isolator is used to isolate the supply as you know.

Similarly there are OCBs (oil circuit breakers), ACBs (air circuit breakers)

GIS (SF6 Gas insulated circuit breakers), etc., These breakers are having

tripping mechanism to isolate the supply whenever fault occurred. The mechanism is driven by protective relays

The tripping mechanism will not be in Isolators

lbs is for isolating 11kv line from the overhead line and isolate the transformer. It may be used in cinjunction with CT and gtripping overcurrent relays for making a compact switching system which is cost effective

N.C.AGRAWAL

Dear Newbie,

First try to understand what an isolator is and then you will figure out the answer to your question. An isolator / disconnector switch is used to make SURE that the circuit is de-energized. Now by circuit I mean MAINS SUPPLY with LOAD. Normally we use isolators so that once the circuit has been properly de-energized we can carry out maintenance work. One more thing isolators may also have an additional ability to EARTH/GROUND the circuit providing additional safety.

Now isolaters can be of many types. They can be used depending on your requirements. General function is the same.

Also remember that they them selves are not major interrupting devices like Circuit Breakers or fuses etc etc. They once act when an interrupting device has performed its duty by interrupting a circuit.

I hope that this information is clear. I tried my best to be straight forward.

Regards,

DG EE

What would the ideal scheme for connecting an isolator would it be before or after the Circuit Breaker

There is no specific name for 11 KV isolator it is called 11KV isolator only and ofcourse the name can be given by any specific companies brand that manufactures it. a 11 KV Isolator is different from ABS. Please check the details at this link http://www.sanghi.info/pro-isolators.html As the name itself suggest it is used for isolation of the 11KV supply . Go through the link you will find the pictures of all the 11KV switches.