IEC TR 62750:2012
(Main)Unified fluorescent lamp dimming standard calculations
Unified fluorescent lamp dimming standard calculations
IEC/TR 62750:2012(E) applies to fluorescent lamp dimming systems. It deals with the interface of fluorescent lamps and dimming electronic controlgear. A unified framework for standardization of fluorescent lamp dimming systems and the associated parameter calculation method are described in this Technical Report.
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Standards Content (Sample)
IEC/TR 62750 ®
Edition 1.0 2012-02
TECHNICAL
REPORT
Unified fluorescent lamp dimming standard calculations
IEC/TR 62750:2012(E)
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IEC/TR 62750 ®
Edition 1.0 2012-02
TECHNICAL
REPORT
Unified fluorescent lamp dimming standard calculations
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
R
ICS 29.140 ISBN 978-2-88912-939-3
– 2 – TR 62750 © IEC:2012(E)
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Explanation of the dimming requirements . 5
2.1 General . 5
2.2 Additional heating. 5
2.3 Cathode heating limits . 6
2.4 Substitution resistors for electronic controlgear qualification. 7
3 Determination of limit values . 8
3.1 General . 8
3.2 Minimum sum-of-squares – SoS (I ≤ I < I ) . 9
min D30 D Dtrans
3.2.1 Lamp and electronic controlgear systems – SoS' . 9
min
3.2.2 Electronic controlgear qualification limits – SoS . 11
min
3.3 Minimum cathode voltage – CV (I ≤ I < I ) . 12
min Dmin D D30
3.3.1 Lamp and electronic controlgear systems – CV' . 12
min
3.3.2 Electronic controlgear qualification limits – CV . 12
min
3.4 Maximum cathode voltage – CV (I ≤ I < I ) . 13
max Dmin D Dtrans
3.4.1 Lamp and electronic controlgear systems – CV' . 13
max
3.4.2 Electronic controlgear qualification limits – CV . 14
max
4 Example of calculation for 54W HO lamps . 14
4.1 General . 14
4.2 Calculation of lamp and ECG systems – SoS' . 15
min
4.3 Calculation of lamp and ECG systems – CV' . 15
min
4.4 Calculation of ECG qualification limits – CV . 16
min
4.5 Calculation of lamp and ECG systems – CV' . 16
max
4.6 Calculation of ECG qualification limits – CV . 16
max
5 Glossary of symbols . 17
Bibliography . 20
Figure 1 – Fundamental circuit for SoS test . 10
Table 1 – SoS parametric values . 9
Table 2 – Fitted power law parameters . 11
Table 3 – Informative parameters for lamp and controlgear systems . 13
Table 4 – Datasheet parameters . 14
TR 62750 © IEC:2012(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
______________
UNIFIED FLUORESCENT LAMP
DIMMING STANDARD CALCULATIONS
FOREWORD
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The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC 62750, which is a technical report, has been prepared by subcommittee 34A: Lamps, of
IEC technical committee 34: Lamps and related equipment.
The text of this technical report is based on the following documents:
Enquiry draft Report on voting
34A/1511/DTR 34A/1546/RVC
Full information on the voting for the approval of this technical report can be found in the
report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
– 4 – TR 62750 © IEC:2012(E)
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
TR 62750 © IEC:2012(E) – 5 –
UNIFIED FLUORESCENT LAMP
DIMMING STANDARD CALCULATIONS
1 Scope
This Technical Report applies to fluorescent lamp dimming systems. It deals with the interface
of fluorescent lamps and dimming electronic controlgear. A unified framework for
standardization of fluorescent lamp dimming systems and the associated parameter
calculation method are described in this Technical Report.
Dimming of fluorescent lamps is becoming increasingly important as a strategy for conserving
global energy resources. This report is the result of many years of effort by global experts to
understand and test fluorescent dimming systems with the objective of standardizing these
systems to grow confidence and reliability in the marketplace. Two theoretical frameworks
have been merged to create this unified dimming standardization method: the SoS (sum of
squares of lead-in-wire currents) and CV (cathode voltage) models. The application of
dimming to actual fluorescent lamp and electronic controlgear (ECG) systems is the primary
concern for reliability in the application and end-user confidence. Characteristics of the
dimming parameter limits described in this report and observed in real system applications
such as in situ field diagnostics are offered as informative. The practical need to use
substitution resistors for ECG qualification is described in this report and also given as
normative parameters in the lamp and ECG standards. No attempt to treat the informative real
lamp-ECG system parameters as normative will be made in either the lamp or the controlgear
standards.
2 Explanation of the dimming requirements
2.1 General
This clause gives a general explanation of the dimming requirements found in the fluorescent
lamp and controlgear standards. Subclause 2.2 provides an overview of the theoretical
framework for the unified dimming standard. Subclause 2.3 provides an explanation of
informative limits for the cathode heating based on physical lamp and ECG systems.
Subclause 2.4 provides the basis for normative controlgear qualification using substitution
resistors. In this Technical Report, the use of primed quantities will signify values obtained
when measuring on actual fluorescent lamp and ECG systems. Unprimed quantities refer to
standardised quantities when testing ECG on substitution resistors. Although lead wire and
lamp discharge currents pertain to actual lamps, they will remain unprimed quantities in this
report.
2.2 Additional heating
It is a well-known fact that, when lowering the lamp current to decrease the luminous flux
(dimming) below a certain current value, the cathode is not heated sufficiently any more by
the lamp current. At these dimmed conditions without added ohmic heating, the cathode fall
will increase to sustain the lamp current and this results in an increased sputtering of the
cathode and thereby a decrease in lamp life. So additional cathode heating is necessary to
keep the cathode at a sufficiently high temperature for thermionic emission. The amount of
this additional heating current through the cathodes as a function of the lamp current is
however dependent on the controlgear circuit layout. There may be a phase shift between
these currents like in circuits with a capacitor parallel to the lamp. In other circuits, the
additional heating current is delivered by
...
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