TYPES OF TRANSFER SWITCH
What Are Electrical Transfer Switches?
Electrical transfer switches are those switches which cause an electric system to switch from one power source to another. This is especially useful if you have a back-up or a stand-by power source for when the main power source gets disconnected for whatever reason.
The most common example of such transfer switches is when the electric supply of a home or office switches from the regular supply of electricity to generator power back up in the case of a power outage. These electrical transfer switches are therefore also known as ‘Generator Transfer Switches’.
Electrical transfer switches are also useful in times when voltage changes in the power supply occur. These voltage changes can cause a lot of damage to the internal circuits of any appliance. In such conditions, the transfer switch will cause a transfer to a generator or a back-up power source, till the voltage has stabilized to normal for some time.
These uses of electrical transfer switches have made them extremely popular with domestic (home) users along with the industrial users.
Types of Transfer Switches:-
- Manual Transfer Switches: These are generally toggle switches or knobs which need to be manually switched on so that the power source gets transferred from one to the other. The manual transfer switches can be used where power outage happens quite rarely and loss of power does not cause any loss to the appliances or systems used with the electric power supply.
- Automatic Transfer Switches: These switches automatically transfer the power source from one to the other. Thus, these are more convenient to use, as one does not have to manually toggle a switch or turn a knob to switch the power source. Automatic transfer switches are useful where even a small loss of power can cause a lot of losses in the system which his being powered by the electric supply. Automatic transfer switches have therefore found their popularity and usefulness in several industrial and commercial applications where a constant source of power is necessary in their processes.
Most of the electrical transfer switches in use are either manual or automatic or even a combination of the two. Nowadays, however, most people prefer the automatic transfer switches as it saves a lot of time and effort.
Methods of Electrical Transfer:-
- Break Before Make: In this method, the transfer switch will break the contact from one power source, before switching to the other power source. This break can be for a small or large amount of time, depending on the configuration of switch used. The advantage of this method is that it prevents backfeeding from the emergency generator into the electric power supply line.
- Closed Transition Transfer Switch: In this method, the transfer switch ensures that there is not much of a time based break in the power supply to the system while it transfers from one power source to another. This is used in industrial and commercial applications where even a small loss of power can cause damage to the product or the system used with the electric power supply. In this system, the generator runs in parallel with the electrical power supply for a certain period of time. This enables the generator to take up the load while the power supply remains uninterrupted.
- Soft Loading Transfer Switch: In this method, a closed transition transfer switch method is used. However, the only difference is that the amount of load accepted by the generator is actively changed with this switching method. This is a more dynamic version of the Closed Transfer Switch method of transfer of electrical power source.
Thus, electrical transfer switches make life easier for common people like you and me, along with industrial and commercial organizations to keep their supply of electric power going on smoothly and in a continuous manner.
