Hubbell YQ-230 internal P.C. board senses both plugs are fully engaged, the polarity of the 30A receptacle on the dock is correct and the two 30A receptacles are from opposite phases.
If an improper wiring condition such as reversed polarity exists on the power center, the YQ230 detects that and shuts the power off. Also, the YQ230 will work regardless of whether the marina is powered with a 125/250V system or a 3-phase 120/208V system.
Internal P.C. Board Senses That:
Application: