Are fans typically permitted on factory floors? What are the common reasons for allowing or prohibiting them?
From an ESD control point of view, anything greater than 300 mm from ESD sensitive items is allowed. Air movement by itself generally does not cause any issues.
Some of our operators use fans, but we ask them to be mostly metal based, as from our verification checks during internal audits the more plastic based units can be high charging (>-1500V) and often these fans aren’t fixed, so can be moved. We also say that if one does have plastic but is fixed over 300mm away from all ESDS items, then it would be ok.
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Hi Santiago.
Be careful that the air flow of the fans does not interfere in the neutralized zone by ionization
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This is a good point guarfj and should be considered by the compliance verification testing. For ionization, the measurements for ionization should be done where the ionization is suppose to be effective. Measurements should be done without any adjustments or before the emitter tips are cleaned.
This will be a good indication of proper selection and placement of ionization.
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Late to the topic, but I’m assuming this will have my reads over time as fans have been questioned many times in our sites.
As everyone has stated, you must consider the use case of the fan and then testing accordingly. Considering not only the fan, but the environment where its being used and possible impacts.
One thing I have found testing the fan itself was most of the very small personal fans are not grounded electrically. Thus any charge that was generated was maintained on the device until contact was made and the charge dissipated. This led to adding a requirement for grounding of fans. If you need the small personal fans, the USB powered include a ground as part of the USB wiring. As long as its plugged in to something with grounded power. This was much easier than physically adding a ground wire to each fan. Most larger fans that we looked at and tested, already had a three prong electrical connection and were fine.
Regards
Chris
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