One more DC hose grounding question.

[NLAlston]

The hose that I picked up, for my Carvewright/DC, is one of those clear, flexible plastic types with wire ribbing which snakes around its entire 10' length. Due to that ribbing, I was wondering if I STILL. might have to undergo grounding steps - or would my type of hose translate into it ALREADY being safe to use with my machine, as it IS?

[fwharris]

I would think you would still need to attached the ends of the wires in the hose to a grounding source.

[Mike58]

I would think you would still need to attached the ends of the wires in the hose to a grounding source.

Floyd is correct.
The wire is molded inside the vinyl and offers no ground path unless you cut the wire out enough on BOTH ends that you can attach it to METAL.
You cannot "ground" to nonconductive material, and the path must be continuous. I used a flexible metal dryer duct. Problem solved with grounding. Floyds DC insert is metal, duct metal and connected to metal housing on the GROUNDED metal DC blower housing.

[NLAlston]

I would think you would still need to attached the ends of the wires in the hose to a grounding source.

Understood, and maybe I should have been a bit more descriptive about what I was, actually, referring to. I knew that there would be the matter of connecting to a grounding source, but wondered if my hose - being wired the way that it is - would be fine to use, with just grounding the ends. I know very, very little about electrical matters, which is why I've asked as I have :).

[fwharris]

Understood, and maybe I should have been a bit more descriptive about what I was, actually, referring to. I knew that there would be the matter of connecting to a grounding source, but wondered if my hose - being wired the way that it is - would be fine to use, with just grounding the ends. I know very, very little about electrical matters, which is why I've asked as I have :).

From what I understand, that is why they have the wire built into the hose, so you should be good to go as is.. No added wire needed.

[bergerud]

I am not so sure that wires inside the plastic will actually ground the hose. Static is a surface thing. If the plastic is an insulator (and it is otherwise you could just ground it), the surface charge will never get to the wire inside. Test it. Try vacuuming dust with and without the wire connected and see if there is a difference. There may not be.

[Mike58]

From what I understand, that is why they have the wire built into the hose, so you should be good to go as is.. No added wire needed.

My understanding of the wire is to reinforce the plastic hose to keep it from sucking together under restricted airflow. My laser has 3 4" hoses attached to the back of it connected by wye pipes into a single 6" metal line that runs into the room I have the 3-1/2 hp blower in. The blower is connected to the metal pipe by the same plastic hose with wire inside it. The blower is rated at 2000 cfm 13 inches water column. When a 24"x48" sheet of material is laid on the cutting table the airflow is reduced to nearly nothing. I have saw the air flow suck slightly warped material flat to the cutting table - hoses must withstand such "abuse" to avoid collapsing. That it also can be used for grounding is secondary.

For what it's worth - My laser is 240volt (grounded) and the blower motor is 240 volts also (grounded) the metal ductwork between them that has plastic hoses on each end has never been grounded, and never caused a problem. I can see where it would be desirable for the CW to have the DC grounded since the machine itself has no ground.

[fwharris]

Maybe I am thinking of a different type/style of hose, or even something else :)! A good test of running the dust collector and dropping saw dust on the hose to see if it sticks or drops off would tell for sure.

[Mike58]

Floyd, with the laser I am mostly sucking smoke. There's ocassionial small "stuff" that may get suck into the air stream. I think grounding IS needed with the CW and DC. When I used the small shop vacuum as a blower while carving there were a few quirky things that happened that might have been due to static electricity. Things that couldn't be explained as to why they happened have sort of stopped happening since I got your DC insert and the HF blower.
So, you have more time and knowledge about the CW than I do; my reference's regarding my laser (as to static) I think are like comparing apples and oranges. I think "we" need grounded DC running the CW!

[fwharris]

Totally agree about the CW needing to be grounded if using a dust collection system.

Yes the static from the shop vac and hose will do crazy things to the machine. I do not even want to count the number of carvings I had to restart. I got lucky and never fried the on board computer or other components.