My 50 amp surge protector has a 50 amp (4 pin) male connector on a short cord that plugs into the shore power outlet. On the face of the surge protector is a 50 amp female receptacle that the 50 amp cord from the 5th wheel plugs into.
From that perspective, my 50 amp surge protector is no different than a standard 50 amp power cord and would plug straight into a 30 amp male/50 amp female dogbone adapter.
Now, a 30-to-50 adapter bridges the 2 each hot legs of the 50 amp service and powers both from the single hot leg of the 30 amp service. It would depend on your 50 amp surge protector as to whether or not it will accept the 2 each hot legs being in phase - i.e., a voltmeter placed between the 50 amp buses will read 0 VAC with the 30-to-50 adapter as opposed to 240 VAC with true 50 amp service.
2016 Ram Longhorn 3500 Dually 4x4 CCLB, 385/900 Cummins, Aisin AS69RC, 4.10
2014.5 DRV Mobile Suites 38RSSA #6972
Come join us on a TEXAS BOOMERS