Installation manual

on the power conductors due to the wire resistance and the current con-
sumption of the connected device. Heavier wire will have lower resistance,
therefore the longer the wire run, the lower the wire gauge. As a rule of
thumb, use 24AWG up to 250 feet, 22AWG up to 500 feet and 20AWG
up to 1,000 feet.
5. For the ATC, see the section on “Length of ATC Cable Runs” (page 3.6)
for the formula to calculate cable runs.
In North America, UL/CSA requires that all wires connected
to the RS-485 bus on the PX-700 be rated Class II and surface
marked VW-1.
Wiring Information ➤ In addition to audio switching and routing, Audioaccess Installations are
data network control systems that operate in a similar fashion to an office
computer network. Consistent polarity and termination of the Audioaccess
RS-485 bus is the most critical element in a reliable and problem-free
Installation. Loose or incorrect terminations of the RS-485 bus will cause
inconsistent operation, lock ups, or even damage to components.
Audioaccess Installations operate on standard RS-485 communications at a
data rate of 9600 baud. An RS-485 transceiver is located in each PX-700
and Audioaccess keypad. The transceiver sends and receives data between
components of an Installation. The four-wire communications bus includes
one power, one ground, and two data wires. The connections of all these
wires are sensitive to polarity. If the lines are connected improperly, there is
the potential for destruction of the transceivers in any component.
NOTE: Make sure all wiring throughout the Installation is consistent:
PWR to PWR, Data 1 to Data 1, Data 2 to Data 2, and GND to GND.
Any inconsistency WILL cause the Installation to fail.
Wiring Warnings ➤ Keep low-voltage cables, especially audio and data wires, well away from
cables carrying AC house current, all antennas, and television cable. If your
wire must parallel these types of cables, maintain at least 12" of separation
and use shielded wire. If your cables must cross AC cables, cross at a right
angle to minimize interference. Never run low-voltage cables though the
same hole as high-voltage AC wiring or through the same conduit.
To avoid damage from nails and screws during construction, keep your
cables at least 2" away from the surface on which the sheet rock or plaster
will be attached. Use metal nail guards in areas where space is not available
or where extra precaution seems appropriate.
Be aware of any remaining electrical or plumbing work to be done after
your wires are in place. Protect them accordingly and inspect them before
they are covered by the wall surface.
PHYSICAL INSTALLATION
3.2