Spec Sheet Preview: Alpha Communications® features a complete line of U.L.® Listed power transformers to power their intercoms, video-intercoms, nurse-call systems, and various signalling systems and devices. U.L.® Listed Power Transformers for Heavy-Duty AC Power Requirements SS050 & SS100 SS250 Alpha Communications® model SS050, SS100 and SS250 Class 1 (primary)/Class 2 (sec …