Ballast Basics I
Presented by: Your Name HERE
ULT Marketing
Universal Lighting Technologies
|
1
Topic Outline
• Fluorescent Lamp & Ballast Functions
• Ballast Types
• Ballast Starting Methods
• Attributes and Measurements
• Advanced Ballast Definitions
• Standards & Regulations
• Lighting Retrofits & Energy Savings
• Controllable Lighting
Universal Lighting Technologies
||
22
Fluorescent Ballast Basics
Before Fluorescent…
Incandescent lamps were the only available electric lighting source, and they are still common
today for a variety of applications.
But… Incandescent lamps are not efficient and don’t last long.
Have you ever touched an incandescent or halogen lamp while it was on?
The heat that incandescent lamps generate demonstrate their inefficiencies as
lighting sources.
Universal Lighting Technologies
||
33
Why Use Fluorescent?
For a basic understanding of fluorescent ballasts, a brief overview of
fluorescent lamps is necessary:
Fluorescent lamps are significantly more efficient than incandescent lamps, using
less energy and lasting significantly longer. This efficiency can be measured in
terms of Lumens per Watt (LPW). This is similar to Miles per Gallon with an
automobile.
•
•
Incandescent
18 LPW
Fluorescent 60-105 LPW
750 hrs. life
20,000+ hrs. life
Fluorescent lamps provide Energy Efficiency & Longer Life
Universal Lighting Technologies
||
44
Fluorescent Ballast Basics
What makes a fluorescent lamp glow?
1.
As an arc current passes through the gas in the fluorescent tube, the electrons flowing
from the electrode at the ends of the lamp collide with the mercury atoms that are in
the gases of the lamp.
2.
The impact of the electrons and the mercury atoms produces ultraviolet rays. These
ultraviolet rays strike the phosphors on the glass wall of the lamp, causing them to
fluoresce and produce visible light.
Universal Lighting Technologies
||
55
Fluorescent Ballast Basics
Incandescent Lighting…. No Ballast
An incandescent lamp operates directly off the power line. Current flows through the filament,
and the filament glows, providing light. The filament also acts as a resistor to limit the current
passing through it.
120 V
Universal Lighting Technologies
||
66
Fluorescent Ballast Basics
Which lamps need ballasts?
All arc discharge lamps such as fluorescent and high intensity discharge (HID) require ballasts for
proper operation. Without a ballast, these lamps will not work.
Linear
Fluorescent
U-Bend
Fluorescent
Circline
Fluorescent
Compact
Fluorescent
HID
Screw-in compact fluorescent lamps include an extremely small
ballast built into the plastic base where the socket is located.
Universal Lighting Technologies
||
77
The Ballast’s Function
The fluorescent lamps require a power device (ballast) that is connected to
them to provide basic operating functions.
1. Supply power to preheat lamp filaments prior to starting (not required for instant start lamps)
2. Provide a high voltage to initiate an arc through the gas in the lamp
3. Control the lamp’s current to within its specifications to provide proper light output and rated life
Input Voltage
BALLAST
3. Controls Current Going to the Lamp
1. Filament Heating
2. High Voltage Across the Lamp
Universal Lighting Technologies
||
88
Ballast Location
Ballasts are an integral part of the lighting fixture. They are
typically located within the fixture covered by a metal
channel.
In down light fixtures for compact fluorescent lamps, the
ballast is mounted on the outside of a junction box that is part
of the lighting fixture.
Universal Lighting Technologies
||
99
Fluorescent Ballast Types
There are primarily two categories of ballast constructions that define the technologies
and materials used to manufacture the ballasts:
 Electromagnetic – The lowest efficiency
 Electronic – The highest efficiency
Universal Lighting Technologies
|
|
10
10
Electromagnetic Ballasts
The first fluorescent lighting systems were
developed with electromagnetic ballasts having
two copper or aluminum wire coils assembled on
steel laminations to create a transformer. The
transformer was designed to provide the right
voltage for starting and was usually connected with
a capacitor to provide the proper lamp current.
Capacitor
Transformer with two coils
assembled with laminations
Universal Lighting Technologies
||
11
11
Electromagnetic Technology

Inefficient circuitry
–
–
–

Generates heat which wastes power
High operation costs compared to electronic ballasts
Operates lamps at power line frequency (60Hz)
Limited flexibility
–
–
–
Typically designed for one lamp or for two lamp operation
Common three or four lamp fixture requires two ballasts
Single product options, typically no alternatives depending upon application requirements

Lamps are connected in series, when one lamp fails, the other lamp extinguishes

Audible, sometimes annoying hum
Due to their inefficient operation, magnetic ballasts for popular lamp applications have
been outlawed by the Department of Energy, but there is still a large installed base.
Universal Lighting Technologies
|
|
12
12
Electronic Ballasts
A block diagram is an easy way to explain how an electronic ballast operates
60 Hz
Input
Alternating Current (AC)
Voltage is converted to a Direct
Current (DC) voltage, like a
battery
The DC Voltage is then
converted to a high frequency
AC Voltage
Components in an electronic
ballast on a printed circuit
board. (Components include
transistors, diodes, capacitors, IC’s,
resistors, etc.)
The High frequency voltage is then
increased to a higher voltage so
that it can ignite the lamps while
also being able to limit the lamp
current
Electronic Ballasts operate the lamps at very high
frequencies which improves lamp efficiencies and
performance.
Universal Lighting Technologies
High Frequency output > 20KHz
|
|
13
13
The High Frequency Advantage
Fluorescent lamps increase in efficiency by more than 10% when operated at high
frequency
Low Frequency and High
Frequency Sine Waves
– At low frequencies, fluorescent lamps actually re-ignite
every half cycle of the input power’s sine wave, using
additional energy.
1/60 Second
– At high frequencies, the fluorescent lamp does not
extinguish, saving energy by not having to re-ignite.
Actual Frequency Depicted is 1500 Hz
Light output as frequency
increases with constant lamp
power
112%
Electronic ballasts are designed to take advantage of this by
maintaining existing light levels and saving energy
110%
108%
106%
104%
102%
100%
98%
96%
94%
60Hz
Universal Lighting Technologies
200Hz 1KHz
5KHz
20KHz
|
|
14
14
Electronic Technology

Efficient Operation
– Technology for lowest operating cost for fluorescent lighting
– High frequency lamp operation improves lamp efficiencies

Application Flexibility
– Products available for operating up to four lamps at once
– Most ballasts are designed for operating different lamp types and quantities
– Multiple product options to choose from depending upon application requirements

Quiet Operation
– The operating frequency of the lamps is higher than the human ear can hear.
Universal Lighting Technologies
|
|
15
15
Starting Methods
There are a number of different methods for starting fluorescent lamps.
T8 & T5 lamps may be started by more than one method. The following is a list of the
starting methods and which ballast technologies employ these methods.
• Rapid Start
– Magnetic & Electronic
• Instant Start
– Magnetic & Electronic
Instant Start and Programmed Start are the methods
currently used for most lighting applications.
• Programmed Start
– Electronic Only
Universal Lighting Technologies
|
16
Rapid Start
Rapid Start ballasts provide filament voltage (heating) and lamp voltage
simultaneously. When the lamp filaments reach a temperature that is sufficient for
ignition with the lamp voltage applied, the lamps ignite.
–
Glowing of the lamps is visible prior to ignition.
–
Depending upon the lamp voltage, this may not guarantee that the filament is sufficiently heated, resulting
in poor lamp life.
–
Cathode voltage remains after the lamp has started consuming approximately 2 Watts per lamp.
It was believed that electronic rapid start ballasts would provide longer lamp life than instant
start ballasts but this has been proven incorrect.
Universal Lighting Technologies
|
17
Instant Start
Instant Start ballasts operate without heating the filaments. A high voltage
is used to ignite the lamps. Instant start operation is more efficient since
there is no additional power consumed for heating filaments.
–Single pin instant start (slimline) lamps must be instant started.
–Some Bi-pin lamps such as the F32T8 and F54T5HO can also be instant started.
Programmed Start is growing in popularity but Instant Start is still by far the
largest segment.
Universal Lighting Technologies
|
18
Programmed Start
Programmed Start ballasts A.K.A Programmed Rapid Start
– Utilize electronic technology to provide optimal starting for lamps to achieve the longest lamp
life possible.
– Tests have shown lamp life to be extended three times as long as traditional rapid start ballasts
in applications where the lamps are frequently cycled on and off.
– Programmed Start ballasts can be used in place of rapid start ballasts since they usually wire the
same way in the fixture, hence the addition of “Rapid” in the name.
Technology for long lamp life!
Universal Lighting Technologies
|
19
Programmed Start
How Programmed Start Circuits Work:
This technology incorporates a “programmed” starting sequence:
Step 1: Application of Filament Voltage (heating)
– Lamp Voltage is kept very low to minimize glow current
– Duration of Step 1 is approximately 800 milliseconds
• Assures that filament temperature is optimal for starting
• Very low glow current during starting prevents damage to lamps
Step 2: Application of Starting Voltage to the Lamps
– When the voltage is applied across the lamps, they quickly ignite since their filaments are already hot
– Short transition prevents lamp damage by minimizing filament sputtering & end blackening
Step 3: Steady State Operation
– Ballast regulates current through the lamp
– Filament voltage is shut off or reduced to improve operating efficiency
Universal Lighting Technologies
|
|
20
20
Best Starting Method
Which Electronic Ballast Starting is Best?
For the lamp types with a choice of starting methods:
 Identify the application and expected operating/switching cycle.
– Expected operating hours between starts.
– Is the ballast connected to an occupancy sensor?
Use Programmed Start to maintain lamp life when:
 Ballasts are connected to occupancy sensors which will switch frequently.
 If the lighting is going to be switched on and off frequently.
– Typically less than three hours per start.
Use Instant start to maximize savings when:
 Ballasts are going to typically remain on for at least three hours between starts.
Universal Lighting Technologies
|
21
Ballast Factor
Ballast Factor (BF) is also referred to as percent light output. It is a measurement of the ballast’s
output and the light level it is driving or controlling the lamp at.
A ballast factor of 1.00 means that the lamp connected to the ballast will be operating at 100% of its
rated lumens. Similarly, a ballast factor of .88 translates to 88% light output of the lamp.
The same lamp will provide different light levels when operated with different ballast factors.
Ballast Factor is a key component in determining the light output of a system
BALLAST
BALLAST
F32T8 Lamp
F32T8 Lamp
Low Ballast Factor Ballast
High Ballast Factor Ballast
Universal Lighting Technologies
|
|
22
22
Ballast Factor
To calculate the lumens coming from a lamp/ballast system, the following equation is
used:
System lumens for a 3-lamp F32T8 fixture with two magnetic ballasts:
Lamp
Rated Lamp Lumens
x Ballast Factor
x Number of Lamps
System Lumens
F32T8
3000
x 0.88
x3
7920
 The rated lamp lumens are found in lamp manufacturers catalogs
 The ballast factor is specified by the ballast manufacturer
Universal Lighting Technologies
|
|
23
23
Ballast Factor
Per ANSI (American National Standards Institute)
 .925 is the minimum BF for a full light output magnetic ballast
 .85 is the minimum BF for a full light output electronic ballast
However, ballast factors can range from .60 to 1.20
 Magnetic residential shoplite ballasts have had BFs as low as .60
– Hence the reason for poor light levels with these fixtures!
As Ballast Factor goes up . . .
. . . the input power for the lighting system also goes up.
Universal Lighting Technologies
|
|
24
24
Electronic BF Options
As electronic ballast product lines continue to expand, their BF options continue to
grow based on the different applications they are serving.

0.88 - Standard Light Output T8
–
–
–

0.78 - Low Power Instant Start T8
–
–
–

Common for new construction and retrofits
Used for frequently switched applications including occupancy sensors and daylight harvesting.
Good solution for education, commercial offices and retail.
Used primarily for retrofit applications
Matches light levels of F40T12/ES (34W) systems
Applications include stairwells, hallways, bathrooms and other areas that are lit partially during the day.
1.18 - High Light Output T8
–
–
–
Used with New construction and retrofits
Ideal for de-lamp applications, high bay fixtures (including warehouses and manufacturing).
It is common for facilities to stock a single lamp and control light output for specific applications with
different BF ballasts.
Universal Lighting Technologies
|
|
25
25
Retrofit Example
The example below compares the lumens before and after a lighting retrofit.
Ballast Type
Lamp
Rated Lamp Lumens
x Ballast Factor
x Number of Lamps
System Lumens
Magnetic
F34T12
Electronic
F32T8
2280
x 0.90
x4
3000
x 0.78
x4
8208
9630

A Ballast Factor of .78 with an F32T8 provides more lumens than the F34T12 lamp with a
magnetic ballast (.90 BF)

If more light output is needed, a higher ballast factor ballast can be installed but it will use
more energy.
Universal
Lighting
Technologies
© 2013
Universal
Lighting
Technologies
|
|
26
26
Universal Input Voltage
Electronic ballast technology has lead to the development of ballasts that can be
connected to different input voltages. This simplifies inventory carrying requirements
and prevents wiring a ballast to the wrong input voltage.
How it works:

Ballast input circuit draws current from the power line and internally regulates the DC voltage
within the ballast. As a result of the regulated DC voltage, the output to the lamps remains
constant.

Ballasts operate from 108 to 305 Volts, 50 or 60 Hertz.
–
120 (-10%) to 277 (+10%)
–
Installer Friendly, two wires, no special taps
Universal input voltage is now common and available for a wide variety of lamp applications.
Universal
Lighting
Technologies
© 2013
Universal
Lighting
Technologies
|
|
27
27
Lamp Configuration: Series VS. Parallel
Some ballasts operate the lamps in series, some in parallel:
Series:
Parallel:
All Magnetic & Some
Electronic
Available only with
electronic
When one lamp fails, the
other lamps extinguish.
When one lamp fails, the
other lamps remain “on.”
Universal
Lighting
Technologies
© 2013
Universal
Lighting
Technologies
|
|
28
28
Selecting a Replacement Ballast

Ballasts are selected based upon the application
–
–
–
Identify voltage (Typically 120 or 277 volts)
Identify lamp type
Identify the quantity of lamps the ballast operates

Refer to Navigator Catalog, Ballast selector Guide or online BallastSpecs, and
using the application information from above, identify the appropriate ballast

Refer to cross references available on www.unvlt.com
Universal
Lighting
Technologies
© 2013
Universal
Lighting
Technologies
|
|
29
29
For Additional Information, please visit our website www.unvlt.com or
use your QR Reader for Smart Phone instant access.
THANK YOU
Website: www.unvlt.com
Nashville Customer Service: (800) 862-8666
Universal Technical Engineering Services: 1-800-BALLAST (1-800-225-5278)
Universal Lighting Technologies
|
|
30
30