For simplex installations select one wide angle float swith. For 115 volts pumps with 3-prong plugs up to 1/2 HP select 20PMD1WP. For 230 volts pumps with 3-prong plugs up to 1 HP select 20PMD2WP. For 230 volt pumps with bare leads up to 2 HP select 30PMPDWOP