and diesel generator and ATS that switches between two electrical sources ??
There may be no difference. It will depend on the application. For example, if I specified an ATS that had the proper voltage and current capacities, the only other item of concern would be to determine if the transfer would be a make before break or a break before make type of transfer. In a make before break, it would mean the sources would be placed into parallel operating condition before one of the sources was interrupted. This would require the ability to synchronize the sources. Which means the frequency, voltage and phase relationship of the sources must match before they are placed into parallel service. On a break before make switch, usually only phase rotation and approximate voltage levels are of concern. Hope this helps, Newton1Law
