Static discharge issues with Festool Dust Extractors

[sandy]

I recently designed a very inexpensive, low-profile,  cyclone pre-separator that mounts on, and connects to, a Festool Dust Extractor (Seehttps://www.etsy.com/search?q=festopper ).  A number of comments that I received related to questions about potential static discharge possibly resulting in damage to the Dust Extractor.  Based on all the concern that was expressed about "antistatic" items connected to Festool Dust Extractors, I decided to check my authentic Festool hoses to confirm that they were conductive.  Well... guess what?  They aren't.  Looking at the Festool products, I noted that they specifically refer to their Festool 452877 Non-Antistatic Hose, 1-1/16 In X 11.5 Ft (27 Mm X 3.5 M).  Ya gotta love that... "Non-Antistatic".  Does that mean "Static"?  Anyway, with a Non-Antistatic hose, I don't see why it should matter what's at the other end.  Maybe someone from Festool can clarify that for all of us.

Sandy

 

[usernumber1]

i think thats the cheap hoses. whereis every festool hose is antistatic almost by default, these are the exception hence 'non-antistatic'

 

[Distinctive Interiors]

Green & Black hoses are Antistatic, Grey hoses are non Antistatic.....452877 is non Antistatic.

 

[Michael Kellough]

[member=3194]sandy[/member] said, “I decided to check my authentic Festool hoses to confirm that they were conductive.  Well... guess what?  They aren't.”

How did you do that?

 

[sandy]

[member=2098]Michael Kellough[/member]

I used a digital VOM, but the result should not be surprising given Festool ‘s own statement that it’s a “Non-Antistatic” hose.

My authentic Festool hoses are green and black, and they came with my CT22E and CT26E Dust Extractors.

Sandy

 

[Michael Kellough]

[member=2098]Michael Kellough[/member]

I used a digital VOM, but the result should not be surprising given Festool ‘s own statement that it’s a “Non-Antistatic” hose.

My authentic Festool hoses are green and black, and they came with my CT22E and CT26E Dust Extractors.

Sandy

I’d still like an explanation of how you used the VOM to test the hose. Not sure lack of “conductivity” and “non-antistatic” are the same thing. As I understand it (only a little) static discharge voltage is extremely high but very low amperage. I don’t know the right way to test that.

Also, only the grey Festool hoses are labled non-antistatic. The green/black hoses are called AS as in anti-static.

In use, the gray hoses will accumulate a lot of dust on the outside. The AS hose will accumulate very little dust on the outside.

 

[Distinctive Interiors]

I've found, especially when cutting manmade sheet material, that using a non antistatic Grey hose can give you a static shock when touching the hose during use. Whereas, the Green & Black antistatic hose doesn't produce the same effect.

It appears the effect is mostly prevalent when working with man made materials.

I tend to only use my 50mm Grey hose for clean up on a Building Site with the Tradesman Clean Up kit. The rest of the time, I use the Green & Black hose whilst cutting, routing and sanding.

 

[Jaybolishes]

I only own anti static hoses and I also have the Oneida cyclone that fits on my ct36ac.  Twice my electronic module has fried and the kick in the pants is I wasn’t using the cyclone either time and I had the anti static hose plugged into the vac directly. Both times I was sanding wood with my Ets150. Second time out of warranty of course.  Now I use my mini as much as possible because it’s never fried and I use the heck out of it without issue. The cyclone gibberish about it causing static problems is completely bunk IMO.

 

[Michael Kellough]

I only own anti static hoses and I also have the Oneida cyclone that fits on my ct36ac.  Twice my electronic module has fried and the kick in the pants is I wasn’t using the cyclone either time and I had the anti static hose plugged into the vac directly. Both times I was sanding wood with my Ets150. Second time out of warranty of course.  Now I use my mini as much as possible because it’s never fried and I use the heck out of it without issue. The cyclone gibberish about it causing static problems is completely bunk IMO.

I’ve used the cheap “clear” Dust Deputy with a CT Mini for years with both AS and non-AS hoses without a ground wire between hose and vac with no problem. Also use same stuff with an old Fein Turbo with zero issues.

 

[Bohdan]

[member=2098]Michael Kellough[/member]

I used a digital VOM, but the result should not be surprising given Festool ‘s own statement that it’s a “Non-Antistatic” hose.

My authentic Festool hoses are green and black, and they came with my CT22E and CT26E Dust Extractors.

Sandy

A VOM can not be used to check for static leakage as the internal voltage is much too low.

Leakage can only be tested for with a megger, a device specifically designed for this purpose, which generates the high voltage required.

 

[wpz]

I was curious, so I just tested some of my festool hoses with an insulation tester (a megger) that builds up to 1000V max.

The megger was connected with a crocodile clamp to the plastic bit that goes into the vacuum and I pushed a probe pin onto the inside of the hose at the inlet (past the rubber sleeve that connects to your tool)

my newest green and black 36mm AS flexible hose (the one with the braided outside) starts conducting at about 140V.
my older green and black 27mm AS hose (with the ribbed outside) started conducting at about 180V.
the grey hoses from my CS50 don't seem to conduct at all (the megger build up to 1005V)

I also saw that the part of the vacuum where you plug your hose in is connected to the ground wire of the vacuum's power plug.

What I found interesting is that the rubber end that connects to your tool is non conductive, so the hose is only anti-static past that connection.
So I guess the idea is that static that builds up in the hose by particles that whizz trough and rub against the plastic of the hose gets diverted to the ground (earth) through the vacuum instead of through a person touching the hose.
It might also help to prevent particles sticking to the hose as static can do that (the famous "rub a plastic ruler in your hair and you can attract little pieces of paper with it" test).

So quite clever engineering, these AS hoses (in my opinion).

Could using a cyclone that is not made of conductive plastic damage the electronics of someone's expensive Festool vacuum? I have no idea, but if I designed such a cyclone (or is it a box that holds another manufacturers cyclone that you designed?), I sure would want to know before I start selling a lot of them (and maybe get a good lawyer [big grin])
No offence intended, just trying to be helpful.

Best of luck,
wpz

 

[Cheese]

I have a Milwaukee and a Fein vacuum and both have non anti static hoses. Vacuuming anything, wood dust, steel dust, aluminum dust, pet & house dust will all eventually charge the hose and you will get zapped. Just the vacuum function itself will charge the hose. It’s the nature of the beast.

I’ve never had an issue with my CT 22 or MIDI. They both have anti static hoses.

Gray is bad...green & black is good.  [smile]

 

[Cheese]

What I found interesting is that the rubber end that connects to your tool is non conductive, so the hose is only anti-static past that connection.
So I guess the idea is that static that builds up in the hose by particles that whizz trough and rub against the plastic of the hose gets diverted to the ground (earth) through the vacuum instead of through a person touching the hose.

I’m not convinced that the rubber connection is non conductive. If it’s black in color then it’s been carbon loaded and will have some level of conductivity associated with it.

It doesn’t make sense that Festool would carbon load a 20’ hose but cheap-out and refuse to carbon load a 5” long connector. The carbon loaded resin for that connector is less than a buck.

These guys are German designers and I doubt they’d take a chance that utilizing a non-continuous ground path would be a wise long-term decision.

Just my [two cents]

 

[wpz]

I think the plastic housing of the machines that you connect the hose to is also non conductive (the tools don't have a ground pin in their plugs, so don't they have to be double insulated?)
So it would not matter that the rubber end of the hose is non conductive, unless if you were to attach 2 hoses together to make 1 really long one (Is this something you can do with the new hoses with the bayonet fitting?)

The plastic part of the end connector is conductive, just the rubbery part isn't. At least as far as I can measure, but maybe I'm measuring wrong. I'll try again tomorrow and let you know.

Would be nice if someone from Festool could enlighten us.

wpz

 

[Cheese]

Would be nice if someone from Festool could enlighten us.

Yes it would...[dead horse]

That’s been one of my largest gripes since I’ve joined this forum. A forum owned by Festool that allows technical matters to be answered by ANYONE including MYSELF  while not prompting one of their technical people to interject and straighten things out.
That’s indeed the goofy part of this forum.

Who’s minding the store?

 

[AlexThePalex]

The plastic of the tool housing is definitely not conductive, so it doesn't matter if the tool end of the hose is conductive.

The static charge loads up on the hose itself, and all you need is a ground connection to dissipate it. You don't need some round circuit from tool to vac to make that work.

Funny thing is my vac & sander combo works as a ground circuit tester. Sometimes I plug my vac in a socket with grounding and still get zapped from the hose, then I know the building's grounding is not working.

 

[RKA]

I seem to recall there was an issue with TS55 saws in the UK which had defective fittings for the hose.  The result was static shocks and the fix was a new fitting.  This would suggest both the plastic fitting and rubber hose end do maintain a ground path. 

 

[Vondawg]

“That’s been one of my largest gripes since I’ve joined this forum. A forum owned by Festool that allows technical matters to be answered by ANYONE including MYSELF  while not prompting one of their technical people to interject and straighten things out.”

Cheese, I couldn’t agree more with you...I love reading/having these discussions (learning and sharing) from all the diverse members skill sets and their knowledge..but like you say, we have “from the horses mouth” final word, from Festool via the FOG, supposedly available but rarely here from them...leaving us with really... anecdotal experiences ....although pretty good ones, thanks to members.

 

[wpz]

What I found interesting is that the rubber end that connects to your tool is non conductive, so the hose is only anti-static past that connection.
So I guess the idea is that static that builds up in the hose by particles that whizz trough and rub against the plastic of the hose gets diverted to the ground (earth) through the vacuum instead of through a person touching the hose.

I’m not convinced that the rubber connection is non conductive. If it’s black in color then it’s been carbon loaded and will have some level of conductivity associated with it.

It doesn’t make sense that Festool would carbon load a 20’ hose but cheap-out and refuse to carbon load a 5” long connector. The carbon loaded resin for that connector is less than a buck.

These guys are German designers and I doubt they’d take a chance that utilizing a non-continuous ground path would be a wise long-term decision.

Just my [two cents]

Well I did some more testing and turns out [member=44099]Cheese[/member] and [member=21249]RKA[/member] were right: the rubber end is conductive!

I connected my hoses to my TS55EBQ (which has one of the newer bayonet connections retrofitted to it) and measured from the blade to the plastic connector at the end of the hose (the side that goes into the vacuum).

With both hoses (the new 36 that fits over the connector and the old 27 that fits inside) a conductive path was there.
Values varied between 300V and 600V, so more than enough conductivety for static which is mostly somewhere between 4000V and 35000V if I'm not mistaken.

Personally I have never been shocked by any of my festool tools, only by some of the prices for parts  [big grin]
I guess those German designers also need to get paid for their cleverness.

wpz

 

[wpz]

Some pictures: