Lightronics RA121 - Manual (Page 3)

Page 3 of 20
RA – 121 RACK MOUNT ARCHITECTURAL DIMMER
Revision 0.93 OWNERS MANUAL 09/26/2011
www.lightronics.com
Lightronics Inc. 509 Central Drive Virginia Beach, VA 23454 Tel 757 486 3588
RA-121 UNIT DESCRIPTION
The RA-121 consists of a processor and 12 dimmer
channels of 1.2KW each. Each dimmer channel is
protected by a 10 Amp circuit breaker. Heavy duty
filtering chokes are used to reduce noise. Dimmer
channel semiconductors exceed a 200% load carrying
capacity overhead allowance. The RA-121 may be
controllad by DMX controllers and several types of
wall remote stations. Dimensions and weight
information is given at the end of this manual.
EXTERNAL CONTROLS
The unit can communicate with remotely located
control equipment in several ways.
A USITT DMX-512 protocol bus is provided so the
unit may be used with any DMX lighting console. The
RA-121 is fully patchable with respect to the DMX
bus.
The RA-121 may also be controlled by several types of
wall mounted smart remote stations. Smart remotes
communicate with the RA-121 by way of a low voltage
RS-485 bus. This bus is completely separate from the
DMX bus. Smart remotes are used to activate scenes
which have been prestored in the RA-121. There are
several types of smart remote stations. Multiple smart
remotes of the same or different types may be chained
together on the RS-485 bus. The same RS-485 bus
may be chained to multiple RA-121 dimmer packs.
The RA-121 may additionally be controlled by an
arrangement of one or more momentary switches
(simple remotes). The switches may be used to control
a specific set of scenes prestored in the RA-121.
REAL TIME CLOCK EVENT SYSTEM
The RA-121 contains an internal clock and timer sub
system. This subsystem may be used to create events
which activate and switch between preset lighting
scenes based upon times, days, and dates. A total of
128 events may be programmed.
POWER REQUIREMENTS
The RA-121 may be operated from 50/60 Hz, 120/208
VAC, three phase power or from 50/60 Hz, 120/240
VAC, single phase power. Input power to the unit
must be capable of delivering 40 Amps per line if
using three phase or 60 Amps per line if using single
phase power.
The RA-121 can operate using only 2 phases of a 3
phase power service. This is NOT recommended since
it causes an unbalanced load to the power feed source.
INSTALLATION
PHYSICAL LOCATION
The unit is intended for INDOOR OPERATION
ONLY and should not be subjected to excessive
moisture or heat. The unit should be installed where a
supply of circulating air is available. The RA-121 is
designed to be installed in a standard 19 inch
equipment rack. Support should be provided at the rear
of the unit if it is installed in a rack.
The RA-121 is fan cooled. Air is drawn in from the
vent slots at each side and exits the unit at the bottom
of the front panel. Be sure that these areas are not
restricted.
POWER INPUT CONNECTIONS
Consult applicable electrical codes to determine the
proper wire type and methods.
The RA-121 operates using either three phase 120/208
VAC or single phase 120/240 VAC power. The unit is
shipped from the factory as a THREE PHASE unit. It
can be field converted to a single phase unit.
WARNING
MAKE CERTAIN POWER IS REMOVED
FROM THE FEED CIRCUITS
BEFORE YOU BEGIN INSTALLATION.