Dust extractor flow in pipes

[Torx]

Here we go then...

https://www.hse.gov.uk/pubns/mdhs/pdfs/mdhs82-2.pdf

Thanks for the link to the Aussie forum, I’ll take a look.

 

[manglitter]

Flexible ducting - use good quality, keep the length to a minimum and earth it if you’re attaching it to steel ducting. Smooth walled steel ducting is better than spiral wound.

I have some steel ducting that I will be installing to my workshop - what is the easiest way of earthing it? I kind of assume that I need to attach a cable to a metal strap around the duct and run outside to a metal spike driven into the ground?

Sent from my SM-G960F using Tapatalk

 

[user22161]

I have some steel ducting that I will be installing to my workshop - what is the easiest way of earthing it? I kind of assume that I need to attach a cable to a metal strap around the duct and run outside to a metal spike driven into the ground?

Depending on ground conditions, earth spikes do not always work well. I would just wire the bonding cable into the nearest ring main power socket.

 

[Torx]

I have some steel ducting that I will be installing to my workshop - what is the easiest way of earthing it? I kind of assume that I need to attach a cable to a metal strap around the duct and run outside to a metal spike driven into the ground?

Sent from my SM-G960F using Tapatalk[/quote]

I’ve never seen anything with a dedicated earth to be honest. I imagine what GrahamF suggests would be belt and braces or perhaps useful if the metal ducting is insulated from other parts of the system by plastic fittings, but assuming the appliance / machine is earthed the typical way it’s done is to expose a bit of the spiral wire reinforcement and either tuck it in under the jubilee clip against the ducting or (better still) crimp some cable to it and fix it to some earthed metalwork.

I do have a video somewhere of what happens when a bag extractor explodes, and I’ve also seen some major static sparks on smaller systems. :shock:

 

[manglitter]

Thanks for the advice Torx and grahamF.
Interested to see that video Torx...

Sorry for the slight thread hijack...

Mike

Sent from my SM-G960F using Tapatalk

 

[Inspector]

Is it for certain that a static spark caused the explosion or a spark from another source? Wood binding in a saw and the blade burning the wood or a screw picked up and hitting the impeller? It is my understanding that a home shop can't create a big enough static spark to cause an explosion. A painful shock, sure. Wreaking havoc in a CNC router and damaging a control board, yes. But there isn't any documented home workshop dust collector explosions, here at least.
Food for thought. http://www.woodcentral.com/articles/sho ... _221.shtml

Pete

 

[Torx]

Is it for certain that a static spark caused the explosion or a spark from another source? Wood binding in a saw and the blade burning the wood or a screw picked up and hitting the impeller? It is my understanding that a home shop can't create a big enough static spark to cause an explosion. A painful shock, sure. Wreaking havoc in a CNC router and damaging a control board, yes. But there isn't any documented home workshop dust collector explosions, here at least.
Food for thought. http://www.woodcentral.com/articles/sho ... _221.shtml

Pete

Yes, I completely agree that the scenarios you mention are much more likely causes of an explosion, but wood dust is highly explosive so worth every caution...you have to remember I’ve had a week of hairdryer treatment from an ex-HSE inspector / specialist witness on the subject (look up DSEAR regulations / ATEX), so my recommendations will always err on the side of caution! I’ll find that video when I’m back at work, it’s a typical cheapo bag extractor on a pressed steel wheeled base - you know the type (but for all I know it could be rigged).

 

[Torx]

Is it for certain that a static spark caused the explosion or a spark from another source? Wood binding in a saw and the blade burning the wood or a screw picked up and hitting the impeller? It is my understanding that a home shop can't create a big enough static spark to cause an explosion. A painful shock, sure. Wreaking havoc in a CNC router and damaging a control board, yes. But there isn't any documented home workshop dust collector explosions, here at least.
Food for thought. http://www.woodcentral.com/articles/sho ... _221.shtml

Pete

That’s an interesting article - thanks! Bedtime reading.

 

[JamieNE]

I’m just going to ask a couple of questions with regards to this kind of thing.
Any help will be much appreciated.

Is there a difference between using a standard 1hp top and bottom bagged extractor with a 100mm inlet and one of the 50litre vacuum type extractors with 100mm inlet?
I was told a while ago and cannot remember for the life of me.
I know they’re different, but I’m hoping to move to a couple of the 50l vacuum types to save space and hopefully increase suction.
One will be solely for the table saw as it’s in the middle of the workshop and the extractor will go nicely under the out feed table.
The other will be set up with a rigid pipe system to accommodate the other things.
What do you think?
Happy to hear all sides.
Thanks in advance.