AMX RDA-ENC2 Instruction Manual page 25

Glossary
Air Gap Switch - A relay or mechanical switch that physically separates a load from the power
feed, resulting in an air gap between the contacts. An air gap is a deliberate and noticeable space or
disruption in a circuit causing an open condition.
AXlink - A four-wire data bus used to transmit and receive data from the AXlink Central
Controller to any of 255 devices on the system. An AXlink address designates which of 255
possible devices assigned to the main AXlink is assigned to the Radia Lighting controller.
Ballast - An electrical device used in fluorescent and HID fixtures. It furnishes the necessary
starting and operating characteristics to the fluorescent lamp for proper performance. Not all
ballasts can dim lights. Fluorescent ballasts may contain the following:
Breaker - An automatic switch that stops the flow of electric current in a suddenly overloaded or
otherwise abnormally stressed electric circuit. A circuit breaker is an air gap switch.
BTU - The acronym for British Thermal Unit. This term also applies to the amount of heat required
to increase the temperature of a pound of water one degree Fahrenheit. It is used to measure the
thermal or heat-producing effect of a device.
CFL Lamp - An acronym for Compact Fluorescent Lamp (a type of fluorescent lamp).
Channel (Radia Lighting) - The Radia Lighting processor's dimming engine recognizes six
independent levels and paths of output control. These control paths are called dimming channels or
just channels. Each Radia Lighting master controller (pack) has six channels of control. AXlink
channels are used in Axcess programming and apply to operation using an AXlink system.
Choke - A device used in electric circuits to oppose changes in the magnitude or direction of
current flow. A choke device reduces noise caused by lamp filaments and is also known as a "de-
buzzing coil."
Contact Closure - A circuit is formed when the two contacts of an open circuit are brought
together. The Radia Lighting master controller uses TTL logic levels normally pulled High to 5v. A
closure to ground pulls the level to logic Low and is read as a closure. Each of the eight closure
inputs is independently operated and controlled.
Contactor - A type of relay that accepts large current loads greater than 20 Amps, usually with a
120-volt primary coil. A contactor is helpful in allowing a 120-volt control signal to switch a large
circuit at 277 volts.
Control Card, also Card - A Radia Lighting master controller on a standard 2.75" x 10" enclosure
plate that is capable of six channels of control, an AXlink connection, a PROlink connection, and a
dry closure connection.
This applies to Radia Lighting models RDC-DC/120, RDC-DC/240, RDC-DC/277, RDC-
PDC/120, and RDC-PDC/240 only.
Radia Lighting Control System
Ballast reactor
Auto-transformer
Power factor correction circuit
Glossary
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