Here is a list of 8 suppliers that come to mind. That's not to say there are not any others that would be acceptable. Remember, to check for the approvals label on any product you purchase, and as well, an application for electrical inspection will be required.
G.E., Zenith ZTX residential / Light Commercial grade automatic transfer switch, 3 pole, Nema 1 Enclosure
ASCO, 220 Volt, 3 Pole, Nema 1 Enclosure
Square D, manual transfer switch, contactor type
Westinghouse, manual transfer switch, 240 volt, 3 pole, double throw safety switch
Reliance Controls LOAD-SIDE™ TRANSFER SWITCHES
Cutler Hammer Transfer Switches AT 3 Pole 240 v 60 hz Nema 1
Kohler, 240 Volt, 3 Pole, Nema 1, Molded Case Style
G.E., manual transfer switch, contactor type, 3 pole
Tony Moscioni
