40 Amps. It will accept 8 to 10 gauge wire.
Part number 300254 is for the 12VBR and 12VBRS2 sealing cap for trolling motor recepticles .
Part number 300100 is the rubber cap for the 12VRC, 12VRC.PG, 12VRC.OEM, and 12VRCY,
Soap and water.
If your basic soap and water doesn’t do the job, there are cord cleaners such as the Star Brite brand available through most marine retailers. Acetone works best for those really stubborn scuff marks.
It is possible the 30 amp receptacles at the dock are on a single phase.Together, they are only putting out 125 volts between them rather than 250 volts which is required for the adapter to work.
Test the two receptacles with a volt meter to confirm there is a total of at least 208 volts between them.
Another possible reason is that the polarity is reversed on the dock receptacles. There are reverse polarity testers available. If your boat’s AC panel is not equipped with one, check with your Marina operator.
The reverse Y adaptor is a sealed unit. We can test, but no repair is possible.