This document provides an overview of a training course on electrical dimmer system maintenance. The course introduces basic knowledge about dimmer units and is intended for technicians with an electrical background. Topics covered include the components and functions of dimmers, types of dimmers, light sources that can be controlled by dimmers, and how to check operation and repair or replace defective parts of dimmer systems. The goal is to enable technicians to safely perform operational and maintenance tasks for dimmer units.

1. AWI 106 Att. 8 Rev. 3 02 Jan. 2011
Date :
Dimmer
Unit
Maintenance
FM-EL-DU-L1-01
QC Department

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Preface
 This course introduces to Electrical Dimmer
System
 It will enable the technicians to obtain basic
knowledge required to perform Operational and
Maintenance tasks, classified as L1 in Electrical
task book, for Dimming Units.

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Background
 This course is intended to technicians who have
basic knowledge and qualification in the field of
Electrical.
 Technicians experience in similar field is
advantageous.

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Topics / Tasks
The Following Topics will be covered during this course
I. What is Dimmer?
II. Basic Types of Dimmers?
III. Main components of dimmer ?
IV. Check operation of system .Check tightness of
connection Repair or replace defective parts
(Check for any loose connections, chances for
heating& burning etc..,) (FM-EL-TB# 010)
V. Question & Answers

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I. What is a Dimmer
 Dimmers are devices used to vary the brightness of a
light. By decreasing or increasing the RMS voltage
and, hence, the mean power to the lamp, it is possible
to vary the intensity of the light output. Although
variable-voltage devices are used for various
purposes, the term dimmer is generally reserved for
those intended to control resistive incandescent,
halogen and more recently compact fluorescent (CFL)
lighting.

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II. What is a Dimmer
 More specialized equipment is needed to dim
fluorescent, mercury vapor, solid state and other arc
lighting.
 Dimmers range in size from small units the size of a
normal light switch used for domestic lighting to high
power units used in large theatre or architectural
lighting installations. Small domestic dimmers are
generally directly controlled, although remote control
systems (such as X10) are available. Modern
professional dimmers are generally controlled by a
digital control system like DMX or DALI. In newer
systems, these protocols are often used in conjunction
with ethernet.

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What is a Dimmer
 Modern professional dimmers are generally
controlled by a digital control system like DMX or
DALI. In newer systems, these protocols are often
used in conjunction with ethernet.
 Modern dimmers are built from silicon-controlled
rectifiers (SCR) instead of potentiometers or
variable resistors because they have higher
efficiency. A variable resistor would dissipate
power by heat (efficiency as low as 0.5). By
switching on and off, theoretically a silicon-
controlled rectifier dimmer does not heat up
(efficiency close to 1.0).
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Basic Types of Dimmers
Older lighting controls used
either resistors or large
variable transformers
called auto-transformers,
These units had hand
wheels mounted on top
that needed to be turned in
order to adjust the level of
output. Needless to say
these devices were very
inefficient, large and
expensive.
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Basic Types of Dimmers
 Modern Triac or Tyristor based dimmers are
either ON or OFF and hence dissipate very little
heat. A typical voltage drop from these units when
the power is transferred to the load is only a few
volts with most of this being lost through the
electrical noise suppression part of the circuit.
The power devices have 3 connections a) Power
in b) Power out c) Gate. The units conduct when
a low power control signal is provided to the gate.
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Basic Types of Dimmers
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Main components of Dimmer
 Dimmer varies the intensity of light emitted from an
electric lamp and provides the flexibility to vary the
amount of light in a given space, depending on the
individual requirements, tasks or activities being
performed.
 An electrical component in the dimmer, the
semiconductor alternistor/triac, turns the light on and
off very rapidly@100 or 120 times per second. The
longer the light is 'on' versus 'off' (example A), the
brighter the lights will be. Conversely, when the light is
'off' more than 'on' (example B), the lower the light
output, making lights appear dimmer.
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What light sources can be controlled by
dimmers?
Incandescent
Magnetic Low-Voltage
Magnetic Low-Voltage
Electronic Low-Voltage
Neon / Cold-Cathode
Fluorescent Dimmable Ballasts
LED (Yes, some LED can be dimmed
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Main components of Dimmer
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PPM Documents.
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Question & Answers
V. QUESTIONS????

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 However, these course are clear in order to
perform maintenance for Dimmer system to
technicians in the field of Electrical.
Conclusion ‫׃‬ -