5-226 C60 BREAKER PROTECTION SYSTEM – INSTRUCTION MANUALCONTROL ELEMENTS CHAPTER 5: SETTINGS5The voltages V1 and V2 are matched automatically so that the corresponding voltages from the two sources are usedto measure conditions. A phase to phase voltage is used if available in both sources; if one or both of the Sources haveonly an auxiliary voltage, this voltage is used. For example, if an auxiliary voltage is programmed to VAG, thesynchrocheck element automatically selects VAG from the other source. If the comparison is required on a specificvoltage, the user can externally connect that specific voltage to auxiliary voltage terminals and then use this "AuxiliaryVoltage" to check the synchronism conditions.If using a single CT/VT module with both phase voltages and an auxiliary voltage, ensure that only the auxiliaryvoltage is programmed in one of the sources to be used for synchrocheck. An exception is that synchronism cannotbe checked between Delta connected phase VTs and a Wye connected auxiliary voltage.2. The relay measures frequency and Volts/Hz from an input on a given source with priorities as established by theconfiguration of input channels to the source. The relay uses the phase channel of a three-phase set of voltages ifprogrammed as part of that source. The relay uses the auxiliary voltage channel only if that channel is programmedas part of the Source and a three-phase set is not.
