Alpha VDU-4 User Manual

VDU-4 Video Distributor Unit

Installation and Use Instructions

Used with the S.T.R.™ Series

Video-Intercoms for systems

with multiple video risers/lines

APPLICATION

The VDU-4 video distributor unit is designed to be used with
the S.T.R.™ video-intercom system(s) to provide multiple video
risers (lines) from a single camera video (coax) source. Each
VDU-4 provides up to four (4) amplified video outputs and a 5th
output that may be used to daisy-chain to an additional VDU­4 unit (if required). Each VDU-4 is powered by a 12VDC-15VDC
power source.

PROCEDURE

1 . Read installation instructions to determine equipment lo-

cation and installation method.
2 . Install equipment and wiring.
3 . Check wiring and connect. Observe all local and

national electrical codes.

4. Apply power and check operation.

HOUSING INSTALLATION AND

EQUIPMENT LOCATION

VDU-4 VIDEO DISTRIBUTOR
The VDU-4 is usually located in the 'central equipment location'
where the system amplifier/power supply is located. You can
mount the VDU-4 by using the provided plastic 'Din Rail'
mounting bracket. It must be located away from any source of
direct heat or extreme cold and in an accessible location. Keep
at least 3 feet (1 meter) away from transformers, light dimmers
or other electrical devices or wiring or sources of electrical
interference.

POWER SUPPLY
The model SS12C (or equivalent) 12VDC plug-in power supply
plugs into a conventional 117 VAC electrical outlet, within 100'
(30 meters) of the VDU-4, but no closer than 3 feet (1 meter) from
the VDU-4 amplifier.

When using any other type of camera(s), each VDU-4 must be
powered by a separate SS12C (or equivalent) power supply, and
not the power source that powers the camera(s)!

WIRING

Run 2 conductor #18AWG from the 12VDC power source to
each VDU-4 video distributor. If distance is greater than 100
feet (30 meters), use #16AWG cable. Use a separate cable from
the video-intercom cables, and route away from any other
cables. Before connecting, make certain wires are free from
shorts or grounds. Make connections as shown on following
page and as detailed in the following instructions.

FINISH INSTALLATION

1 . Install VDU-4. Do not overtighten screws.

2. Install amplifier and accessory devices as needed.
3 . Plug SS12C power supply into outlet. Observe all local and

national electrical codes.

4 . Make sure all coaxial connections are connected properly

and no braid wires are touching or shorting to the center
conductors of the coaxial cables.

NOTE: The Alpha Communications

system is installed or used in any manner other than described
in this manual.

®

warranty is void if this

TROUBLESHOOTING

If the VDU-4 fails to operate as indicated in these instructions,
check the following points:

1. NO VIDEO OUTPUTS AT ALL: Check 12VDC -

15VDC power at each VDU-4 video distributor; and for 117
VAC at power supply primary.

NOTE: When using a conventional S.T.R.™ entry camera
unit, the camera is powered by 12VDC-15VDC, and the power
is applied to terminals marked 'B' and 'O'. When using this
type of camera, the first VDU-4 may be powered by the same
power source that connects to terminals 'B' and 'O'. Simply
run two (2) wires to terminals 'B' and 'O' on the VDU-4 unit
as well as the camera. POLARITY MUST BE OBSERVED.
Terminal 'B' is positive (+) and terminal 'O' is negative (-), at
all such connections! Each additional VDU-4 should be pow­ered by a separate SS12C (or equivalent) power supply.

Copyright© 2001, Alpha Communications®, All Rights Reserved.

2. PROBLEMS WITH INDIVIDUAL VIDEO
OUTPUT(S): Temporarily move coax cable from video

output (1-4) that is not functioning, to one that is function­ing properly, to see if it is the VDU-4 output or coaxial
cable(s) that are not functioning properly.

If these checkpoints fail to indicate the problem,
there may be an equipment fault. Contact the
factory or qualified service representative.

AWD061 Rev. 2 (09/01)

TYPICAL WIRING LAYOUT DIAGRAM SHOWN FOR TWO (2)

VDU-4 VIDEO DISTRIBUTOR UNITS, WITH UP TO EIGHT

(8) VIDEO OUTPUT RISERS (LINES).

(SHOWN WITH 6 VIDEO OUTPUTS BEING USED)

MAXIMUM OF 10 VIDEO MONITORS ON EACH

VIDEO OUTPUT OR 300' (90 METERS) OF COAXIAL CABLE

**

Notes:

1. Wiring to 12VDC input power should be #18AWG unless shown otherwise. If any wire run exceeds 100 feet
(30 meters) use #16AWG in place of the #18AWG.

2. Observe all local and national electrical codes.

3. All terminals connections shown may not be in the order that they appear on the equipment.

4.

See also the wiring information on page 1 for more wiring details.

*

ALPHA COMMUNICATIONS® • 42 Central Drive • Farmingdale NY 11735-1202

TOLL-FREE TECHNICAL LINE 1-800-666-4800 • Phone: [phone] • Fax: [phone]

INTERNET WEBSITE: http://www.alpha-comm.com • EMAIL: [e-mail]

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