Q. What is the GO switch or GO AB switch, construction, working principle, types, parameters and testing?

Gang Operated (GO) switch is an electrical device that is used for High Tension (HT) power supply 11KV or 33 KV switching. It is commonly used for receiving power supply from Electricity Board (EB) board and distributing to the consumer HT panel or transformer.

1 - Full form of 11/33 KV GO Switch or GOAB Switch

GO Switch: Gang Operated Switch.
GO AB Switch: Gang Operated Air Break Switch.

2 - Definition:

GO switch is used for making and breaking high voltage power supply in substation and industries premises. It is used in a combined three phase or triple pole so It is given the name gang-means a group of phases. It is used outdoor for the distribution of HT systems.

It is working on two no poles in the air so its other name is GOAB switch. It is operated manually in mechanical function by handle after disconnecting the load. The handle is installed on a pole distance of ground at 4 feet.

3 - Construction:

The required essential parts list of gang operated air brake switch is given below mentioned.

Sr.No	Part Details
1	2 no iron pole.
2	Phase coupling shaft.
3	Operating rod.
4	Operating handle.
5	Horizontally mounted switches.
6	Post isolator.

4 - Working Principle:

When the GO switch is operated manually by the handle upside or downside, the air will be available as a dielectric medium for the GO air-break switch. The air is the best medium for any arc quenching so It is the best and most reliable device in comparison to other switches.

The air-break switch has both the blade and the contact furnished with arcing horns. Metal type of arcing horn which is the arc produces due to interrupt current. When the switch is open, the arc spreads farther and farther apart, and the arc lengthens until It finally breaks.

5 - Required parameters of 33KV and 11KV GO Switch?

Sr.No.	PARAMETERS	11 KV	33 KV
1	System voltage	11 KV	33 KV
2	Highest System Voltage	12 KV	36 KV
3	Temperature	40°C to 60°C	40°C to 60°C
4	Relative Humidity	70% to 100%	70% to 100%
5	Rated normal current	400 A	400 A
6	Short Circuit current and time	3 sec, 31.5 KA	3 sec ,25 KA
7	Highest load capacity	400 A	400 A

6 - Types of GO Switch:

Different types of GOAB switches are used as per requirement in industries. Vertical types are used Commonly as endpoint users in distribution Systems.

Sr.No.	Types
1	Horizontal Mounting type.
2	Vertical Mounting type.
3	Rotating type GOAB switch.
4	Composite polymer AB switch.
5	Double stack tilting type.
6	GO DO combined switch.
7	Single phase GOAB switch.

6 - Type of test for equipment health:

For equipment better health, some health test is performed like as temp test, breaking capacity test, short circuit test, and others. by these below mentioned test we can find out the actual health of equipment. It is pre-precaution for the safety of the GO switch.

Sr.No.	Type of test
1	Temperature increasing test.
2	On load breaking capacity as per rating.
3	Short time current as rating.
4	Offload current capacity of braking.
5	Line charging breaking capacity test according ratings.
6	Dielectric strength test one minute withstands voltage.
7	Maximum rated current withstands capability.
8	Mechanical and electrical durability.

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