An alternator switchboard has a synchroscope and synchronizing lamps, if the synchroscope is broken, which of the steps listed is the most essential before an alternator can be paralleled with the bus _____.

题目介绍: Analternatorswitchboardhasasynchroscopeandsynchronizinglampsifthe synchroscopeisbrokenwhichofthestepslistedisthemostessentialbeforean alternatorcanbeparalleledwiththebus_____., The breaker should be closed when one synchronizing lamp is dark and the other isbright?The breaker should be closed when both synchronizing lamps are bright?The frequency meter should be used to determine that the incoming alternator frequencyis slightly higher than the bus?A portable phase sequence indicator must be used to verify the information from thelamps? 本题为最佳选择题收录于二管轮题库中。