Spec Sheet Preview: The Alpha Communications® 'NH' series power supplies are used with the HT3000 and HT2000 series handset stations to provide intercom amplification and power to operate the associated intercom system, and certain optional components and/or accessories, such as electric door opener(s) etc. All of these power supplies operate on 16VAC (30VA) low-voltage Class II wiring. For permanent transformer mounting use our Model SS106 (U.L. Listed) transformer. For plug-in transformer connection use our Model T1640 (U.L. Listed) transformer. …