-1- G/TBT/N/THA/3 20 
Explanatory Memorandum  
Of the d raft ministerial regulation  on high efficien cy electronic  ballasts   
for fluorescent lamps  
B.E. …  
-------------------  
Principle  
Definitions of high efficien cy electronic ballasts  for fluorescent lamps  
Rationale  
It is hereby deemed appropriate and necessary  to define  an electronic ballast  for a 
fluorescent lamp  that has an energy consumption value not more than is specified in this 
ministerial regulation  as a high efficiency electronic ballast  for a fluorescent l amp. The 
purpose  of th is regulation  is to conserve  energy and to promote the us e of energy -efficient  
materials . This will provide manufacturers and sellers of such product s with t he right to 
support and assistance from the Energy Conservation Promotion Fun d. It will encourage the 
manufactur e and sale of this type of ballast. C onsumers will be able to use energy 
economically and efficiently, and will have the option to use  high efficien cy electronic  ballast s. 
This will promot e the country’s energy consumptio n efficiency and reduc e pollution . 
 -2- DRAFT  
Ministerial Regulation  
Definitions of high e fficien cy electronic b allasts  for fluorescent l amps  
B.E….  
-----------------------------------  
In accordance with S ection 6, Clause 2 and Section 23, Clause  1(2) and Clause 3 of 
the Energy Conservation  Promotion Act, B.E. 2535, with amendments made in the Energy 
Conservation  Promotion Act  (Issue 2), B.E. 2550  contain ing a number of  provisions related to 
the limitation of private rights and libert y as permitted  in Section 2 9, together  with Section 33, 
Section 41 and Section 43 of the Constitution  of the Kingdom of Thailand  – with the guidance  
of the National Energy Policy Committee  – the Minister of Energy issues a  ministerial 
regulation as follows:  
1. In t his ministerial regulation:  
“Ballast” means an electronic  ballast f or a fluorescent lamp with a capacity  as 
specified in this ministerial regulation.  
“Fluorescent lamp” means a hollow tube fluorescent lamp either in a linear or circular 
shape that  can be used with a single -phase alternating current of 220 volts, with a frequency 
of 50 Hertz, excluding fluorescent lamp s that generate visible off-spectrum light for exit signs 
and illumination in hazardous  areas.  
"Energy consumption  value” means the total power input of a ballast-lamp circuit  
being tested , after correction  for reference state . 
“Ballast -lamp circuit” means an electric circuit or part of an electric circuit composed  
of ballast  and lamp, usually as part of  a light fitting . 
“Reference lamp” means a fluorescent lamp selected for  testing. When connected to 
the reference ballast under  specified condition s, the lamp  will have  electrical characteristic s 
similar  to those specified for  the standard for each lamp type according to IEC 60921 or IEC 
60929 or Industrial Standar ds 1506.  
“Reference ballast” means a special ballast designed to be used as a standard for  the 
ballast being  tested, and for select ing the reference lamp. This reference ballast must have  
the necessary characteristic s including the required  frequency , a stable ratio of voltage  over  
power input, and must be unaffected by  electric current  fluctuation , surround ing temperature 
and magnetic field s in accordance with  Industrial Standards 2319 or Industrial Standards 
1506 or IEC 60929.  
 -3- 2. High efficien cy ballast s must have an energy consumption value no t more than as 
specified in the ministerial regulation , considering the economic situation , the government ’s 
energy polic ies, the readiness  of ballast manufactur e and sales, as well as  support and 
assistance provid ed to manufacturers and sellers  of ballasts . 
The energy consumption value must be defined in respect to the fluorescent lamp 
power specified by the manufacturers as follows:  
Fluorescent lamp  power  
(watt s) Energy consumption value  
(watt s) 
18 (linear shape ) 19.0 – 16.0 
32 (circular shape ) 35.0 – 30.0 
36 (linear shape ) 36.0 – 34.0 
 
3. The formula for calculat ing the ballast energy consumption value  is as follows:  
 
  
 means  the energy consumption value which is the total 
power input of the ballast -lamp circuit  being tested , 
after correction for reference state . The unit is the 
watt.  
 
 means  the electric power input of a ballast -lamp circuit 
which  is connected to the reference lamp and the 
tested ballast. The unit is the watt.  
 
 means  the specif ied electric power or specific power  of the 
reference lamp  at high frequency, based on  the 
lamp information table. The unit is the watt.  
 where  
 means  the electric power of the reference lamp that can be 
measured when connected to the reference ballast. 
The u nit is the watt.  
 
 -4-  
  
 means  the ratio of light output  of the tested system 
(tested ballast -reference lamp ) over the  light 
output  of the reference system ( reference 
ballast /reference lamp) that can be calculated 
from the formula:  
   
 
 when  
 is the light output of the reference lamp when 
connected to a tested ballast. The unit is the 
lumen.  
 
  
 is The light inten sity from  the reference lamp when 
connected to the reference ballast. The unit is the 
lumen.  
 
4. The test for determining  the energy consu mption value of the ballast must be 
carried out by the organi sations specified and announced by the minister.  
5. The standard  and methodology of the test  for determining  the energy consumption 
value  of the ballast must comply with the specifi cations as pu blished  by the minister.  
 
Given on:  B.E. … 
 
Minister of Energy