What Are Automatic Transfer Switches?

Automatic transfer switches are a critical component of any emergency or standby power system.  When the normal or preferred source of power is lost, it quickly and safely shifts the load circuit from the normal source of power to the emergency or alternate source of power. Because of this, it permits critical loads to continue running with minimal or no ouTAGe.  It also has a re-transfer process that returns the load circuit to the normal power source, when the normal power source has been restored.
 
It has three basic components. One, it has a power switching device to shift the load circuits to and from the power source. Two, it also has a transfer logic controller that monitors the condition of the power sources and provides the control signals to the power switching device. The third component of automatic transfer switches is the control power source, which Supply operational power to the controller and switching device.
 
What makes this power-switching device different from the manual type of power switching device? With a manual model, you will need to start your generator and connect it to the power-switching device during power ouTAGe. Then you will need to switch your house over to generator power. When the utility power is restored, you will need to switch your house back to utility power, and turn off your generator. 
 
However, with the automatic transfer switches, everything is fully automatic. Thus, when the utility power goes out, it will signal your generator to start. Once the generator is running, it automatically connects your home or business to the generator. When the utility power is restored, it will then reconnect your home or business to the utility. Then it turns off your generator and waits patiently for the next power ouTAGe. 
 
In buying these devices, you need to remember that when you want to run your enTire house in case of a power ouTAGe, and you have a large enough generator, you will need a device that is the same rating as your main breaker panel. For a home, this will normally be either 100 or more likely 200 amps. The power-switching device should be installed between your main breaker, which is normally found at the Meter, and your main electrical panel. Some homes have a 400 amp service utilizing two distribution panels, in which case you will need two 200 amp or one 400 amp automatic transfer switch. 
 
However, if you want to run only a certain loads during a power outage, you can install a sub panel off your main panel and use a 100-amp power-switching device.  This is a great idea if you do not have a generator big enough to run everything.  
 
Automatic transfer switches are usually designed for use with a permanently installed standby generator. And they can come with a built in load center that saves space and makes installation easy.  It is a device that comes in handy for companies and household that has a generator. 

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