Found in industries that depends totally on electricity to run their business, many manufacturing concerns have a standby generator ready in case there is a blackout so they will not suffer any losses due to the blackouts. In order to keep the factory running smoothly without any downtime, the generator must be hooked to the main supplies coming from the electrical authorities so in cases of emergencies, power can be transferred smoothly from the generator to the usual electrical system with any danger of clashes between the supplies coming from the authorities with the supply coming from the generators. This is achieved through he use of a Generator Transfer Switch. Sometimes it is also called a changeover switch.
These switches when compared to the switches in our homes is huge as it must be able to handle a very high demand of electricity. The terminals are also quite different from what we normally see. There will be three rows of terminals In normal cases, the center terminals are the main wires that carries the current to the Main Switch Board, The left terminal are the incoming supply from the electricity provider and the right terminals are the tapped to the supply lines from the generator.
For safety purposes, this switch can only work one way at any one time. That means if you pull the switch to the left, the electrical supply from the normal provider will be in contact to the terminals in the center row which sends the electricity to the Main Switch Board. This is the position that this switch will stay in normal times when there is no breakdown or blackouts.
In times of a blackout, the transfer switch is changed over to the right side so the terminals to the Mains gets in contact to the terminals with the supply coming from the generator. When this switch is pulled to the right it makes a clean disconnection from the terminals on the left side and vice versa. this ensures that the two power sources don’t clash in case the normal electrical supply come back on.