ANSI C82.6:2005 pdf download.Ballasts for High-Intensity Discharge Lamps – Methods of
Measurement.
4.4 Lamp Stabilization.
4.4.1. Lamp pre condition:
The lamps used for ballast measurements shall, unless otherwise specified, have been seasoned a minimum of 100 hours poor to their use in the ballast tests.
4.4.2. BasIc stabilization method:
Before any measurements are taken, the lamp shall be operated within ± 3% of rated wattage in an ambient temperature of 25°C ± 5°C until the electrical parameters of the lamp cease to change. The lamp burning time required to achieve this lamp stabilization is a minimum of 30 minutes. It could be as much as 6 hours or more for a metal-halide lamp if the lamp is moved while it is still hot or if its orientation is changed. After the stabilization process has begun. the lamp shall not be moved or repositioned until after the testing is complete. In order to avoid heating up the test ballast during lamp stabilization, causing resistance changes and therefore resulting in unrepeatable data. it is necessary to warm up the lamp on a standby ballast. This standby ballast should be a commercial ballast of a type similar to the test ballast in order to be able to switch a stabilized lamp to the test ballast without extinguishing the lamp. A fast-acting switch Is recommended: however, a make-before-break switch may be required on a high-pressure-sodium lamp to prevent it from extinguishing during switchover Once the lamp has been transferred to the test ballast circuit, re-stabilization time is important and is typically 1 minute for mercury and high-pressure-sodium lamps and 3 minutes for metal-halide lamps. To avoid test ballast heat-up, measurements should be taken within 5 minutes after re-stabilization.
If a HPS lamp ballast is under test the lamp wattage with a standby ballast should be adjusted to .1- 2% of the nominal lamp wattage, (see ANSI C78.42) if the ballast does not have a fixed
power output design.
(Intorniative Note: The effect of heat on ballast operation is under considecahon by me ad hoc group.)
4.4.3. Alternative Stabilization method:
Because in some cases, such as low frequency electronic ballasts, the transfer from the reference ballast to the ballast under test is undefined, the following alternative method should be tollowed to ensure testing result reproducibility:
4.4.3.1. The lamp characteristics should be determined with a reference ballast and recorded for future comparison.
4.4.3.2. The same lamp will be driven by the ballast under test for 15 minutes.
4.4.3.3. The electrical measurements should be taken within 2 minutes after the 15- minute stabilization period.
4.5 Instrumentation
CAUTiON: Certain instruments connected in parallel with the lamp may be damaged or destroyed when subjected to the starting pulse of ballasts that supply such pulses (such as those for high•pressure sodium and metal-halide pulse-start lamps). It is recommended that such instruments be connected after the lamp is started and that some arrangement be provided to remove the lamp ignitor from the circuit or otherwise prevent the ignitor from unexpectedly operating.
(Note: digital instruments, that meet the requirements described in this standard, are preferred to analog instruments).
4.5.1 Accuracy. It is desirable that instruments be chosen so that the indicatons to be read will be in the upper third of the range. Instruments should be selected which have a guaranteed accuracy commensurate with the requirements of the test and shall not have an accuracy less than the following:
4.5.1.1 Analog Instruments:
Ammeters and voltmeters: 0.5% up to 800 Hertz
Wattmeters: ±¾ % upto 1000 Hertz fOr power factors of 5O’% to 100%; ± 0.5% up to 125 hertz for low-power-factor (0% to 20%) circuits.
4.5.1.2 Digital Instruments: Accuracy (X percentage of the reading + V percentage of the scale per instrument manufacturer specification.)
