The Alpha Communications®/S.T.R.™ SNT333
Switching Power Supply is used only with the 2-
wire QwikBUS™ series intercom and/or video-
intercom systems. The SNT333 provides the regu-
lated 24VDC power needed to control the SP333
QwikBUS™ intelligent controller.
Each SNT333 gets its power from a customer
supplied power cord, and will operate on an input
of 100 to 240VAC.
Each 2-wire QwikBUS™ system requires a mini-
mum of one SNT333 Switching Power Supply.
• Easily Installs Right on Finished Wall Surface or in
Optional Junction Box
• Operates on Safe Low-Voltage Class II Wiring
• Positive Screw Terminal and Plug-in Connectors
Height: 3.75" (96mm)
Width: 3.15" (81mm)
2.25" (58mm) from mounting
Construction: High impact ABS plastic case
Positive screw terminal and plug-in
0-50 degrees C.
Surface-mounted (usually installed near
the SP333 intelligent controller and
other system central equipment).
Rev. 1 - 05/07
ARCHITECTS' AND ENGINEERS'
The Switching Power Supply unit(s) shall be Alpha
Communications®/S.T.R.™ QwikBUS™ model
SNT333, or approved equal. The SNT333 shall be
built into a rugged high impact ABS plastic case, and
shall be powered a contractor supplied power cord.
Contractor shall furnish the proper C333-2 connect-
ing cable to connect to the SP333 intelligent controller
and to the model T1240 (12VAC) power transformer.
Low voltage wiring shall be used and positive screw
terminal and plug-in connectors shall be provided for
installation wiring. The SNT333 shall be mountable
right to the surface of the wall or in a customer-
supplied junction box cabinet.
Contractor shall observe all local and national electri-
cal and building codes.
Copyright© 2007, Alpha Communications®, All Rights Reserved
42 Central Drive • Farmingdale NY 11735-1202 • Phone (631) 777-5500 • Fax (631) 777-5599