Light armature failure investigation report

Transcription

1 Light armature failure investigation report Report no : 06C00290RPT01 Status Report : Final Brand : Comhan Holland B.V. Type no : Serial no : n.a. Date of receipt : 2006 March, 10 Date of measurements : 2006 March, 10 Date of report : 2006 March, 24 This publication may be entirely reproduced and/or made public. Separate parts of this publication may not be reproduced and/or published by print, photo print, microfilm or any other means without the previous written consent of D.A.R.E!! Consultancy. All rights and obligations of contracting parties are subject to either the Standard Conditions of D.A.R.E!! Consultancy or the relevant agreement concluded between the contracting parties. Checklist no: 06C00290RPT01.doc Page 1 of 11

2 Manufacturer: Comhan B.V. Postbus AC UITHOORN The Netherlands Measurements carried out on behalf of: Comhan B.V. Postbus AC UITHOORN The Netherlands Applicant's representative: In the capacity of: Measurements carried out by: Mr. T. Sanders Manufacturer D.A.R.E!! Consultancy Vijzelmolenlaan GX Woerden The Netherlands Test engineer: P.A. de Graaf Test engineer D.A.R.E!! Consultancy: D. van der Vlugt Director Checklist no: 06C00290RPT01.doc Page 2 of 11

3 Contents 1 Introduction Intentional test set-up causing the blinking phenomen Additional tests causing the blinking phenomen Additional tests not causing the blinking phenomen Protective earth disconnected TL armatures displaced from framework Conclusion Work-around Checklist no: 06C00290RPT01.doc Page 3 of 11

4 1 Introduction D.A.R.E!! Consultancy has been asked bij Comhan B.V. to investigate the issue of flickering and blinking of the Framelight, a poster light armature. The EUT consists of an aluminium framework, electronic ballast, Philips type HF-P 254 TL5 HO , and two TL armatures. Comhan has asked D.A.R.E!! Consultancy to investigate if the blinking effect is caused by EMC phenomena. The EUT was reported to start blinking during operation without depicted cause. During the EMC tests this was noted, however not because of the EMC phenomena applied. The findings are elaborated in the proceeding. Checklist no: 06C00290RPT01.doc Page 4 of 11

5 EUT specifications PIN-number: 06C00290 EUT description: Framelight Brand: Comhan Holland B.V. Type number: Serial number: n.a. Voltage supply: 230VAC Rated power: n.a. Peripheral equipment: None Dimensions (L*W*H [m]): 93*130*4cm Condition upon reception: Software release number: n.a. PCB release number: n.a. Environment to be used: Domestic Cables connected to EUT Description Port Type Type Of Cable Cable Length Fixing shield Load at port Power AC Mains Unshielded 3m n.a. Mains Test results Test sequence Phenomenon EUT modified Results 1 Conducted Immunity -- Pass Checklist no: 06C00290RPT01.doc Page 5 of 11

6 1.1 Intentional test set-up causing the blinking phenomen AC mains AC Line filter EUT Anechoïc, shielded room The line voltage (rms) was checked. This showed inside the anechoic room 228VAC, to 230VAC outside the Anechoïc-room. Additional voltage variation tests from a dedicated power source showed no change in performance or blinking down to 137VAC. Additional to this the AC voltage shape is observed and simulated with the AC power source. Neither this set the EUT to blink and concluded is the harmonics in the line voltage can not cause the effect. Checklist no: 06C00290RPT01.doc Page 6 of 11

7 1.2 Additional tests causing the blinking phenomen Extension cord EUT AC Mains Line filter When an AC line filter is connected to the same (adjacent) power socket of the extension cord, the EUT starts blinking. This set-up simulates a typical situation in which the EUT is used in practice during for example at exhibitions. The line filter showed, simulates an imaginary electrical/electronic device comprising a line filter at the power entry. A typical line filter consists of capacitors connected from the line/neutral to safety ground (PE). During testing, the EUT showed to blink when: -the line filter is connected to the power socket first, and after that the EUT is connected to the extension cord. During testing, the EUT did not show to blink when: -the EUT was connected to the extension cord, where after the line filter was connected to the adjacent AC mains socket. -the EUT was connected to the extension cord, where after the line filter was connected to the adjacent socket in the extension cord. -the line filter was connected to the adjacent socket in the extension cord, where after the EUT was connected to the extension cord. -the line filter was connected to the AC mains socket, where after the EUT was connected to the adjacent AC mains socket (without the extension cord). -the EUT was connected to the AC mains socket (without the extension cord), where after the line filter was connected to the adjacent AC mains socket. Checklist no: 06C00290RPT01.doc Page 7 of 11

8 1.3 Additional tests not causing the blinking phenomen Protective earth disconnected EUT L1 Extension cord L1 N N AC Mains PE PE Not connecte d Line filter In the figure above, the EUT protective earth is not connected to the mains socket. In this configuration it was not possible to get the EUT blinking. Warning This configuration is only used for testing purposes, for safety reasons this should not be done in practice. Once the EUT is lit, connecting the PE to Mains PE did not cause the EUT to blink. Checklist no: 06C00290RPT01.doc Page 8 of 11

9 1.3.2 TL armatures displaced from framework 1) TL armature fixation, extruded profile screwed to under laying framework with three screws. 2) Extruded profile and TL removed from under laying (metal) framework (grounded). 3) TL armature extruded profile around TL tube 4) Extruded profile completely removed The TL tube is installed in an extruded (metal) profile. At the side of the profile a gap is located for the illumination of the display. When the profile including TL is isolated from the grounded framework, the EUT was not blinking at the start-up conditions (extension cord, line filter etc.). See the pictures above for details. Checklist no: 06C00290RPT01.doc Page 9 of 11

10 1.4 Conclusion It can be concluded that earth leakage current in the EUT electronic ballast causes the unit to malfunction. The tests show a combination of mains power impedance, capacitive decoupling of mains power to ground (PE) and capacitive leakage current via the armatures set the EUT to blink at start-up. This phenomenon is illustrated in the following figure. Armature Extension cord impedance Balast Frame Leakage current Capacitance Checklist no: 06C00290RPT01.doc Page 10 of 11

11 1.5 Work-around The next figure illustrates a work-around which reduced the blinking effect during start-up. Frame PE Inductance Balast L1 Mains N During the test, with this modification, it was not possible to reproduce the blinking in this configuration. The applied inductance was a Wurth Electronic WE , 100 uh type. Note: Using an induction between the framework and the PE is tested successfully as well but should be avoided for low voltage safety purposes. It should be noted that this shows a solution for the blinking effect, however extensive test configurations (cable length, capacitive coupling to mains etc.) is required to gain proof. Other options (not tested) is to apply an isolation transformer between the mains power and the EUT. For implementing this in the EUT this is however a costly and difficult solution to implement. Checklist no: 06C00290RPT01.doc Page 11 of 11