Electrical power outages may come unannounced and sudden, reasons are many and can range from poor quality parts or simply wear and tear. These power outages could cause important loss of data and productivity for both businesses and households alike.
The purpose of standby generators are basically to provide power when the mains utility supply fails. To prevent the two sources of power from being mis-synchronised together, standby generators are typically connected to the load via an Automatic Transfer Switch (ATS). Under normal operating conditions the mains utility powers the load via the ATS. When the utility supply fails, the ATS detects the loss of power and sends a signal to start the generator and transfer the power source from the utility to the standby alternator once at rated speed and voltage.
There are three common types of ATS switches used:
- Open-transition transfer devices: when the source fails, the open-transition transfer device opens the connected source before engaging the new source. This causes an interruption of power for a small period of time.
- Fast closed-transition transfer devices: operates similar to the Open-transition transfer devices but uses a ‘make-before-break’ switching action on return of original source by paralleling both sources for approximately 100 milliseconds. This device limits power interruption upon returning to mains utility.
- Soft closed-transition devices: operates like an open-transition transfer switch but when transferring power from one generator to utility, the control system will synchronise the sources and gradually transfer the load.
The type of ATS is selected based on the application requirements. Most ATS systems include a bypass switch which can be used for maintenance purposes.
Normal businesses and people can carry on with their activities while standby generators continue to supply power until electricians have finished fixing the problem in the electrical system. Therefore standby generators has been increasingly seen as a simple yet effective solution to protect the consumer from the negative effects of a sudden failure in the electrical system.