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Electrical Wiring Anomaly

Views: 2439

#65387

Electrical Wiring Anomaly | 7 November, 2011

We have four pick and place machines all exibiting a residue that seems to build up over time on wiring and electrical components. This residue appears as a white haze on wiring, caps and fuses (these are the components where it is most obvious). You can easily wipe the haze off with your finger almost like when you breathe on your glasses and clean them. It is very strange because it is isolated to these machines only. Additionally, it seems to be isolated to certain power circuits - example, a row of clear glass fuses, one for a 48VDC circuit, the other for a 24VDC circuit and the 48VDC circuit fuse will develope haze as the other will not. Has anyone seen this before and now what might cause it?

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#65397

Electrical Wiring Anomaly | 8 November, 2011

I do not have a answer for you, but it sounds like electro-static charge is making air-borne particles stick to the machine. What are the air handling conditions? Could be you need a better filtration system. I use a HEPA filter system. I've always wondered if it is necessary, but then again I've never had problems either. Which reminds me, I just noticed the "change me" light today.

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#65403

Electrical Wiring Anomaly | 9 November, 2011

By no means clean room but pretty clean environment. We have ultrasonic air humidifiers maintaining our air at about 45 RH. I agree with you about airborne stuff attaching to electro-static. It's a mystery why it is isolated to four machine, though. These machines are all powered by a big UPS, so...?

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#65407

Electrical Wiring Anomaly | 9 November, 2011

The white haze is most likely coming from your ultrasonic air humidifiers. I have seen this from a home unit that left a white residue on furniture in the house. What is your water source for the humidifiers? If it is hard water you will get more of the white residue. We had to use reverse osmosis water in the humidifier which cuts down the white residue to almost nothing. Why it is on certain areas and not others could be due to electrostatic charge or just the proximity of that equipment to your air vents.

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#65410

Electrical Wiring Anomaly | 9 November, 2011

The water source is D.I. water.

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#65411

Electrical Wiring Anomaly | 9 November, 2011

I've never run D.I. water through an ultrasonic humidifier before. I think the reverse osmosis (RO) process removes more stuff (minerals and etc.) than the D.I. process does. My experience from using one in a home setting still tells me that is the source of your white residue. I'm guessing it is a fairly major change to start using RO water in your humidifiers but I bet your white residue will disappear if you do.

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#65413

Electrical Wiring Anomaly | 9 November, 2011

Thanks for the input. We'll take look at that.

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