Thread: DE for a kinda small shop

1hp units aren't worth the box they come in for dust extraction and if you want to run proper machinery (jointer/thicknesser/table saw) a shop vac won't work - they can't move enough air. The generic 2hp units will run off normal power points, 3hp should also be ok on 10A power.

6" hoses are better than 4" and venting outside is always a good idea if you can.

Ultimately, it comes down to your budget. How much are you willing to spend?

ok, that's along with my where my thinking is at, so that's good. The 1hp units looked pathetic in my mind, and the shop vac is all huff and no actual results.

I'm actually surprised you can run 2hp on 10A power. I've almost no knowledge of electrics, so as i understand it if there's two sets of two 10A outlets on the wall (4 total), you're able to draw a maximum of 20A ? Or are they normally wired separate, so 40A ? I wouldn't want to overheat the wires in the wall though i'd assume the breaker would trip first.

The only other reason i wasn't sure about venting outside was due to noise, but i figure with half the room basically single pained glass i'm already beyond that as an issue.

i'm willing to spend $3000 if i have to. Medical bills cost more than tools.

I am in similar situation, small workshop with, small thicknesses,dewalt bench saw, bandsaw and hand power tools.
at present I have a carbatec 2 hp dust extractor https://www.carbatec.com.au/dust-con...ld-code-fm-300

im not happy with the amount of sawdust it collects, I still have to do heaps of sweeping to get the workshop clean after cutting small amount of wood
I'm told this is a low preasure high volume dust extractor.

i was at hare and Forbes today and they had high pressure low volume dust extractors https://www.machineryhouse.com.au/R871

which would be better for my application, I'm only using one machine at a time.
any help or suggestions would be appreciated

as i understand it, the low pressure systems are good for collecting fine dust suspended in the air from things like sanding, or from devices like planers that put out a ton of air on their own, whereas high pressure systems are better for collecting from point sources like hand power tools or for general clean up. I'm intending to use both eventually but i just didnt know if the generic 2hp systems were worth anything. I'm in nz, so prices are pretty steep here. Being a small shop it's pretty easy to instantly spike the air dust levels too so i want to make sure i dont fire up a big tool and come out the room looking like an acme bomb went off in my face )

@48buster this video seems useful, https://www.youtube.com/watch?v=E2ivsVOp8NY

Originally Posted by sirex

I'm actually surprised you can run 2hp on 10A power. I've almost no knowledge of electrics, so as i understand it if there's two sets of two 10A outlets on the wall (4 total), you're able to draw a maximum of 20A ? Or are they normally wired separate, so 40A ? I wouldn't want to overheat the wires in the wall though i'd assume the breaker would trip first.

Power = Volts x Amps, so the maximum you can draw from 10A is 2400W or a bit over 3hp. I don't know how house wiring works, my knowledge is limited to Yr 11/12 Physics, but the breakers are there to make sure you can't overload anything

Originally Posted by sirex

as i understand it, the low pressure systems are good for collecting fine dust suspended in the air from things like sanding, or from devices like planers that put out a ton of air on their own, whereas high pressure systems are better for collecting from point sources like hand power tools or for general clean up.

Got it in one. The biggest Festool vac moves about 137cfm, the biggest Makita does 127cfm, the basic 2hp unit does about 10 times that

The recommended flow for a 6" jointer it about 350cfm and a 12" thicknesser is about 500cfm, you do the math

Unless you can see the 2 sets of 10A outlets wired back to their own breaker, this means they are probably wired into one of the household 10A circuits.

Originally Posted by elanjacobs

Power = Volts x Amps, so the maximum you can draw from 10A is 2400W or a bit over 3hp. I don't know how house wiring works, my knowledge is limited to Yr 11/12 Physics, but the breakers are there to make sure you can't overload anything

Multiple 10A sockets are often wired to a 16A breaker. Breaker ratings are for continuous power but they can handle much higher currents for a limited period of time such as when machines start up.

DCs are one of the few WoodWorking machines that draw their rated power most of the time so a 2HP DC will draw ~1500W or 7.5A.
On start up where the current will get up to ~30A.
A 2HP Table saw will only draw its full power (7.5A) when it's making its deepest cuts, for small stuff it might only be drawing half that.
This is why you can run a 2HP TS and DC from 10A sockets.

Got it in one. The biggest Festool vac moves about 137cfm, the biggest Makita does 127cfm, the basic 2hp unit does about 10 times that

The figure provided for vacs assume,
- clean filters
- no power tool connected
- no hose
When these are taken into account the flow drops to <100 cfm

When long narrow hoses are used and non Festool power tools are connected it drops even more.

A Basic 2HP (in fact almost any) DC will only do ~400 CFM through a 4" hose (the limit is the hose)
When connected to 6" Hose the limit is now the front entrance of the DC and the connection between the impeller and the bag - read the sticky on the generic 2HP DC for details

The recommended flow for a 6" jointer it about 350cfm and a 12" thicknesser is about 500cfm, you do the math

They're minimums, that won't cover all situations.

If the power tool has a built in fan, that will be the limiting step for air flow at both high and low pressures - in that case low pressure systems can be used.
I use my 3HP DC and 50 mm hose on my belt and ROS sanders with built in fans.

Originally Posted by sirex

i've trying to set up a small shop in less than ideal conditions. It's basically just a room of my house which i'm in the process of converting. At the moment there's still carpet & curtains in there so it's very early days, It's ~10m2 (~110ft2) and space is hence kinda limited. The room has an HRV ceiling outlet in it (a home ventilation system from the roof space) so there's ventilation of the room which'll be taking the air through any cracks or drainage holes around the window, a quarter of which can be opened but which is single glazed and covers almost all of one of the long walls (the room is roughly 4.5x2m, with the other long wall have a door on it). What that means is that wall space is very limited and there's likely a constant air movement in the room which i suspect is likely to keep the invisible dust moving around constantly 24/7.

One of your early DC tasks should be to seal your workshop off from the rest of the house.
including a firewall in the roof cavity or on the upper face of the ceiling joists.

The reason you are mystified is not the electricity. It is because HP is a meaningless unit. Work in Watts and it will be simple.

Watts = Amps x Volts.

ANZ have a 235volt system for single phase. So that number will be constant.
Hence Amps = Watts / Volts.
In our case for single phase power Amps = Watts / 235.

So a normal 10Amp circuit is 10 x 235 = 2350 Watts.
If your machine uses more than 2350 Watts then you have a problem.

In a house it is normal to wire up a couple of rooms on a single 10 Amp circuit. So chances are high that all the sockets in your single room are on one 10A circuit.
The lighting is on a separate circuit.
Thus everything turned on and drawing energy at any point of time in your workshop will need to be less than 2350 Watts.

To check this the circuits should be labelled in the switch board but inevitably in an old house they are not. What you can do is count the number of rooms in your house. Count the number of circuit breakers in your switch board.
In the switch board there will be a dedicated circuit breaker for the hot water and one for the oven. So deduct 2 from the number of circuit breakers you have. This gives you a rough idea of how many rooms are sharing 10Amp circuits.
For example. Say my house has 7 rooms. My switch board has 6 circuit breakers or fuses. 6 -2 = 4. So 7 rooms are sharing 4 circuits.

So you will have to assume that your room has a maximum power from all sockets of 2350 Watts. Say your DE uses 2000 Watts. That leaves you with 235W to run a machine. Which is about enough for a small radio and not much else. In that scenario you are going to need a sparky to add at least one more circuit.

For exceptional requirements there can be a 15 Amp circuit. Like for the oven for example. However normally these have things hard wired into them or special plugs to discourage the average punter from using them. This is because 15A at 235v is more likely to kill someone than 10A. So it's limited to special requirements. Such as that crazy bugger with the special woodworking machines.

So forget about HP. Work in Watts and it will be clear what you need to do.

Note that 3 phase power has different voltage and different wiring to allow a lot more power so discuss that with your electrician. Most will come and give you quick advice and a quote for free.



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Originally Posted by DaveVman

. . . ANZ have a 235volt system for single phase. So that number will be constant.

Not quite so, Australian standard mains household single phase V it is supposed to be 230, +10% to -6%V (Anywhere from 243 to 216V) and its definitely not constant.

So a normal 10Amp circuit is 10 x 235 = 2350 Watts.
If your machine uses more than 2350 Watts then you have a problem.
.
.
Thus everything turned on and drawing energy at any point of time in your workshop will need to be less than 2350 Watts.

Unfortunately it's not that straight forward.

For example, despite the Australian Standard, here in Perth, we're typically on 250V (I monitor it fairly regularly and at my place its typically from 245 to 255V - right now its 252V) and electrical stores here sell the same GPO/cable/appliances etc as the east coast so an absolute 2350W on a 10A circuit is not the case.

There are a number of instances when the power draw can legitimately go over the 10A.

Every time a 2HP motor starts motor starts it draws >30A for a couple of seconds, but it runs fine on a 10A circuit.

Most breakers can also run for some 10s of seconds on currents significantly greater than their ratings

You will find that 10A GPOs are connected to typically 16A and sometimes 20A breakers.

What matters is, is the wiring capable of handling the current being drawn? Breakers should be selected by the sparky that protects the wiring, the appliances are supposed to look after themselves.

For exceptional requirements there can be a 15 Amp circuit. Like for the oven for example. However normally these have things hard wired into them or special plugs to discourage the average punter from using them. This is because 15A at 235v is more likely to kill someone than 10A. So it's limited to special requirements. Such as that crazy bugger with the special woodworking machines.

There's nothing particularly special or exceptional about the 235V in the 15A GPO, its just as likely to kill as the 235V in a 15A GPO.
In fact 10A and 15A GPO circuits are often identical except that multiple 10A GPOs can be connected to the same breaker whereas only a 15A GPO should be connected to its own breaker.

The reason for this is because 15A devices usually drawn a high continuous current and hence start a fire.

Getting back to using a 2HP (1500W) TS and a 2HP (1500 W) machines on one 10A circuit - how is this possible as this adds up to 3000W?
The main reason is the breaker on the circuit is probably a 16A breaker (3760W) continuous.

In practice while the 2HP DC will draw its full 1500W continuously, the TS will only draw close to its full power while it is making a deep cut.
Most of the time the TS will be idling along at <half its rated power but for a short time a TS may even safely draw 50%+ more that its rated power while under extreme load.
The combo of the DC and TS may for short periods even exceed the Breaker current but they should be able to handle this.
OTOH if you try and drive a gnarly hard piece of timber through the TS with a blunt blade for a few minutes, most 16A breakers will not cope and drop out

On my 3HP TS (2250W) is on a 15A (3750W) breaker.
It draws ~1250W while idling, 3000W on a deep cut, and when I really push it to its limits >4000W but for a brief period (<10s) without tripping the breaker. Its a toss up between the breaker and the motor's own thermal cut out switch as to which one just out first. If I take it straight to 4250W the motor thermal cut out goes before the breaker.

So it's a bit more complicated than most people think and usually be left to a sparky to sort out so you can claim on your insurance when you start that fire.
The sparky will ignore the concept of10A @X V, and will look closely at the GPO, breaker and wiring rating. If you chose to run too many devices on that circuit that's your problem and you will call him back to install another circuit.

thanks bob there's a lot of great information in there. I had wondered about peak loading vs constant draw etc. I just got hold of a kill-a-watt power meter device so i'll see if i can find out the power draw and such of the TS and then i'll know what sort of ballpark i'm in for the DE. The TS has soft start on it so hopefully that'll help. If needs be i'll get a sparky in to add some more 20A breakers for the room and outlets. Fortunately the circuit breakers are on the outside of that room's exterior wall so shouldn't be too big a job.

One other question, potentially a dumb one. DE units are normally run continuously while in the shop ? or do they just get turned on / off for each cut / set of cuts ? Just wondering how often that peak loading might occur.

Agreed with BobL on the "add new circuits".

Everything is a cost and its very hard to work out where to spend the $$ first. There are conflicts everywhere demanding your limited resources.

I just had the studio redone this week... super fat mega lines brought in from the external box, then dedicated 15 and 20 amp circuits everywhere, each protected with individual RCD's.

Its a job that should have been done a long time ago but only really became a problem as I grew into the sport. More and more machines, bigger motors and running things continuously created problems.

Its either get more power and do it properly or follow the "hand tool" route. A 2hp dusty and table saw are pushing the limits of an ordinary household circuit.

A 2HP dusty with pleated filter has been my friend for some time now. It is just about to be upgraded to a 3hp with 6" and PF.

It is absolutely terrible how bad the dust collection offerings are here in Oz. Woeful. Extremely awful and 100% crap. I sincerely hope that someone like Oneida starts direct selling here to raise the bar.

Originally Posted by sirex

One other question, potentially a dumb one. DE units are normally run continuously while in the shop ? or do they just get turned on / off for each cut / set of cuts ? Just wondering how often that peak loading might occur.

Big workshops find it easier to leave DEs running continuously but it's unusual to do that in DIY workshops.

Certainly just leaving a DE system on just while making the dust will not clear all the dust from a shed and it should be left on for some time after the dust making activity,

The extent to which DEs should be left on depends on a number of factors including, the nature of the work being performed, the machinery being used, the size of the shed, the effectiveness of the DE including general ventilation systems.
Some examples

Thicknessing inside a large shed using a small DC with minimal ventilation
For 30 minutes of continuous thicknessing I would recommend leaving the DC running until you leave the shed.
One piece through the thicknesser I would leave the DC running for 10 minutes afterwards

Table saw in a small shed with a large DC and good ventilation
For one cut every minute or so I would suggest just leaving the DC running.
For a single cut , leave the DC running for a couple of minutes after completion.


Now no-one is going to get out their slide rule and calculate the time needed every time so this is where an "auto delay off" switch is useful.
My home made switch box uses a 10 minute delay, it's probably over kill because I have an additional 1200 cfm of ventilation that I switch on even before I start making dust and I tend to leave this running until I leave the shed.

An alternative to leaving the DC running for long periods is to install separate quieter, high capacity, low resistance and low power use fans.

Then there's the air con to worry about but I won't go into that here.

Woodpile: It is absolutely terrible how bad the dust collection offerings are here in Oz. Woeful. Extremely awful and 100% crap. I sincerely hope that someone like Oneida starts direct selling here to raise the bar.

I'm not that impressed by the oneida systems. The cyclone designs they used are similar to the old designs used in the carbatech cyclones and appear to rely on brute strength.

Woodpile