Synchro-Check (Paralleling) Protection Relay
The synchro-check relay can be used to assist in the semi-automatic paralleling of two ac power systems. The volt-free relay contacts change state when the voltage level, phase relationship and frequency are within the selected synchronizing limits. Connecting two electrical systems that are not closely matched can cause expensive damage and disturbance to the electrical system. Using this relay will ensure that damage will not occur.