Thread: Clearvue CV1800 / Max Impeller Install - Home Garage Workshop

Originally Posted by BobL

Couplers in WA have 180 mm diam flexy in about a dozen different materials but for rigid ducting you would have to go galv.

And roll it yourself or have it custom made including all fitting, bends etc.

Originally Posted by Chris Parks

Me too. Bill Pentz advised me in discussions I had with him during testing and evaluation of running the cyclone in Oz that we stick to an upper limit of 70hz. His reasoning was that a material collision with the impeller could be contained in the housing if the speed was held to those figures but there has been at least one collision that penentrated the housing and that was below 60hz IIRC. I have always wondered what the fan curve does above 60hz and where the point of no return for an increase in speed occurs. I suspect that the entry and exit of the housing may well be the bottle neck and in the US they have found that 7" duct on an 1800 gives far better results. Try buying 7" duct in this country and people look at you strangely as if you should be committed. A very interesting thread, what current does the system run at with blast gates open?

Hi Chris. The current draw indicated by the VFD is as follows;

Inlet blocked @ 60 Hz = 4.5 amps
Inlet Open @ 50 Hz = 6.6 amps
Inlet Open @ 60 Hz = 9.5 amps (9.6 amps with a bell-mouth hood)
Inlet Open @ 63 Hz = 11.1 amps
Inlet Open @ 70 Hz = 15.0 amps

9.5 amps at 60 Hz seems low to me considering I have yet to connect any inlet ducting. Any thoughts? Perhaps my exhaust ducting and chinaman's hat is producing too much back pressure? I didn't check the system without the exhaust connected (it would now take a bit of surgery to disconnect - but I'm tempted to do so).

Cheers,

Dom

Originally Posted by DomAU

Hi Chris. The current draw indicated by the VFD is as follows;

Inlet blocked @ 60 Hz = 4.5 amps
Inlet Open @ 50 Hz = 6.6 amps
Inlet Open @ 60 Hz = 9.5 amps (9.6 amps with a bell-mouth hood)
Inlet Open @ 63 Hz = 11.1 amps
Inlet Open @ 70 Hz = 15.0 amps

9.5 amps at 60 Hz seems low to me considering I have yet to connect any inlet ducting. Any thoughts? Perhaps my exhaust ducting and chinaman's hat is producing too much back pressure? I didn't check the system without the exhaust connected (it would now take a bit of surgery to disconnect - but I'm tempted to do so).

Cheers,

Dom

The numbers will fall for inlet open when you get the ducting installed due to lower air flow, I will check some numbers and get back to you. It would be interesting to see what other installations get, any other users care to comment on either system?

John Samuel reports some currents here Making 150mm DC ports for workshop machines
Unfortunately there is only one common situation between your and John's testing and that is for all gates closed at 60Hz where John measures 3A.
I seem to remember he posted other data on currents but I cannot find them - Where are you John??
Anyway you will find that post most instructive in terms of improving your machine collection points

Originally Posted by DomAU

Hi Chris. The current draw indicated by the VFD is as follows;

Inlet blocked @ 60 Hz = 4.5 amps
Inlet Open @ 50 Hz = 6.6 amps
Inlet Open @ 60 Hz = 9.5 amps (9.6 amps with a bell-mouth hood)
Inlet Open @ 63 Hz = 11.1 amps
Inlet Open @ 70 Hz = 15.0 amps

9.5 amps at 60 Hz seems low to me considering I have yet to connect any inlet ducting.

It does seem low - but why are you worried about connecting ducting as this will reduce the current.

Any thoughts? Perhaps my exhaust ducting and chinaman's hat is producing too much back pressure? I didn't check the system without the exhaust connected (it would now take a bit of surgery to disconnect - but I'm tempted to do so).

I doubt the exhaust will do much, but I would still encourage you to do this. I recommend making all components as disconnectable as possible until you finalise your setup.

BTW The currents displayed by VFDs are not always what they seem. When I compare them with my calibrated Fluke Ammeter the currents shown by VFDs are rarely the same (usually too low) and some differ considerably. Sometimes this is because the VFD currents displayed are individual phase currents (x 1.7 to get total current) but sometimes they are not this either. Even the high quality Honeywell VFD I have does not agree with my Fluke.

Originally Posted by BobL

John Samuel reports some currents here Making 150mm DC ports for workshop machines
Unfortunately there is only one common situation between your and John's testing and that is for all gates closed at 60Hz where John measures 3A.

That is way too low, it must have been wrong for whatever reason. The only common way for users to report current draw is to do it from the VFD to get somewhat consistent results. Very early users will have a Huanyang and everyone else a Powtran so reported results should be fairly consistent.

The only other variation is single phase or three phase supply to the VFD, what is your Dom?

Originally Posted by BobL

It does seem low - but why are you worried about connecting ducting as this will reduce the current.

BTW The currents displayed by VFDs are not always what they seem. When I compare them with my calibrated Fluke Ammeter the currents shown by VFDs are rarely the same (usually too low) and some differ considerably. Sometimes this is because the VFD currents displayed are individual phase currents (x 1.7 to get total current) but sometimes they are not this either. Even the high quality Honeywell VFD I have does not agree with my Fluke.

I realise that connecting ducting will only further reduce the current and that is exactly why i'm worried; I was hoping that even with ducting connected I would be using close to the maximum rating of the motor which would mean that the system was flowing maximum air for the HP available. If it ends up only needing 2.5 HP for example, then I should have; increased impeller / blower size further (not really possible) or increased the inlet (and main ducting) and/or exhaust ducting size. Otherwise it feels like I'm not getting the best out of this system.

I was wondering about the accuracy of the VFD ammeter but figured in this day and age it couldn't be that expensive to get a proper reading. I may try to borrow a calibrated Fluke and verify the VFD numbers.

Chris, my input is single phase 240 volt to the VFD.

Originally Posted by DomAU

I realise that connecting ducting will only further reduce the current and that is exactly why i'm worried; I was hoping that even with ducting connected I would be using close to the maximum rating of the motor which would mean that the system was flowing maximum air for the HP available. If it ends up only needing 2.5 HP for example, then I should have; increased impeller / blower size further (not really possible) or increased the inlet (and main ducting) and/or exhaust ducting size. Otherwise it feels like I'm not getting the best out of this system.

At this stage the limit will be your impeller housing swept volume and the other changes you suggest won't make much difference.

The dust ports are always going to be the rate limiting step it's probably better to work on those first.

It's also better for the motor NOT to be running continuously at full power anyway as this will reduce its life.

Well, I didn't get much time today with family events and bike training, but I started on ducting the 150 mm PVC pipe through the ceiling. I've decided to run the main branch in the ceiling and have a few branches coming down through the plaster for each machine / area. I'll post a little sketch of the network later, but basically 1 main trunk all the way across the garage (about 8 m) with two trunks spitting off at 45 degrees to either side of the garage (and then dropping down) and then a couple more branches coming straight down into the garage from the main trunk line.

I purchased 45 degree junctions (about 16 I think) and will use two for each 90 degree turn with a small section of straight in between each, as well as 5, 45 degree Y-junctions and 3, 6 m lengths of 150 mm stormwater PVC. I also purchased a flex coupler for the inlet and a few end caps in case I don't finish all of the runs at once. I have some 6" blast gates I got from Stephen at clearvue and will use those for the most part - no plans to automate for my small shop.... yet .

I bought all of the PVC fittings and pipe at a local plumbing shop (McCanns Plumbing in Bacchus Marsh). It's local, the guy actually drove the 3 lengths home for me after work (he lives not far away) and the pricing was actually far cheaper than one other place I rang to just make sure I wasn't paying way too much (something Eden I think - happy to pay more if it's local but don't want to get completely fleeced). In total I think I paid about $550- for the lot.

Now, here is where I'm going to get criticised; I needed to connect my cyclone inlet up to the ceiling and only had about 80 cm horizontally to do so and make a 90 degree bend. Instead of using PVC for this I decided to use some heavy duty "smooth bore" flex hose in a very gentle curve. I may be wrong, but I actually think that this will be a better transition into the inlet than running multiple 45 degree PVC bends so close to the inlet and I hope will provide a little less vibration transmission from the cyclone to the rest of the PVC network and ceiling. The smooth bore flex is genuinely nearly completely smooth bore and is very rigid (this is about the minimum bend radius in the photo) there are no corrugations inside and the spiral is outside of a smooth liner. We'll see. I got this hose through Bearing Wholesalers and I think it cost about $90-100 per meter (used 1.1 m here).

I actually think that to minimise system effect one would ideally make a longer rectangular inlet or extension to the rectangular part of the inlet into the cyclone as the round to rectangle transition just before the cyclone can't be great.

So inlet connected and hopefully tomorrow I'll get a few minutes to run more PVC in the ceiling and start cutting holes for the drop-downs.
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Also, I'm sure most of you are already aware of this trick, but given the 150 mm stormwater PVC is actually about 162mm OD and flex hose is 150mm ID, you can simply make a cutout in a piece of MDF with a bit of a radius and using a heat gun, heat the pvc until it goes fairly elastic, then gently squeeze it through the form to make a perfect 150 mm (or whatever you need to allow you to get the flex hose onto) section to get your flex hose onto.

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Originally Posted by DomAU

Now, here is where I'm going to get criticised; I needed to connect my cyclone inlet up to the ceiling and only had about 80 cm horizontally to do so and make a 90 degree bend. Instead of using PVC for this I decided to use some heavy duty "smooth bore" flex hose in a very gentle curve. I may be wrong, but I actually think that this will be a better transition into the inlet than running multiple 45 degree PVC bends so close to the inlet and I hope will provide a little less vibration transmission from the cyclone to the rest of the PVC network and ceiling. The smooth bore flex is genuinely nearly completely smooth bore and is very rigid (this is about the minimum bend radius in the photo) there are no corrugations inside and the spiral is outside of a smooth liner. We'll see. I got this hose through Bearing Wholesalers and I think it cost about $90-100 per meter (used 1.1 m here).

We have a similar problem at the mens shed. I've made an 8" to 9" transition and we will use 9" flexy to go through the wall. Our trunkline is going to be in 9" galv,

Also, I'm sure most of you are already aware of this trick, but given the 150 mm stormwater PVC is actually about 162mm OD and flex hose is 150mm ID, you can simply make a cutout in a piece of MDF with a bit of a radius and using a heat gun, heat the pvc until it goes fairly elastic, then gently squeeze it through the form to make a perfect 150 mm (or whatever you need to allow you to get the flex hose onto) section to get your flex hose onto.

Good idea!

Managed to get up in the ceiling in-between training and drinks today for a couple of hours. Man I hate working up in that dusty, dark and cramped roof space! Make sure you wear a dust mask! Unfortunately one of the branches required some s-bends to get around rafters etc. Fortunately this one is for the band-saw which doesn't require maximal CFM.

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I cut the corresponding holes through the plaster from below using a router and template. This is not a neat way to cut plaster! Also, despite thinking I'd checked, I'd suggest you make 100% sure there aren't any power cables near where you are cutting holes. After routing out this one I noticed a power cable about 1 cm from the cut!

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That looking like a real labour of love and I hope you get it right. Knowing how often I have played around with my setup after it was installed the thought of getting up into the ceiling to lengthen/shorten acting and add/subtract junction would be pretty daunting.

Originally Posted by BobL

It's also better for the motor NOT to be running continuously at full power anyway as this will reduce its life.

The CV cyclones both here and in the US have always had motors rated for more power than needed precisely for that reason. An 1800 can be run with a 3hp motor but because the power required is a tad over 3hp a 5hp motor was always specified. The motor we went to when the US sourced motor became unavailable (the US govt legislated it out of existence) is a tad over 4hp so has plenty of headroom and duty cycle available.

Originally Posted by Chris Parks

The CV cyclones both here and in the US have always had motors rated for more power than needed precisely for that reason. An 1800 can be run with a 3hp motor but because the power required is a tad over 3hp a 5hp motor was always specified. The motor we went to when the US sourced motor became unavailable (the US govt legislated it out of existence) is a tad over 4hp so has plenty of headroom and duty cycle available.

Yeah, based on amp draw numbers from US forums and then fact that I was going to use the 16" impeller I was worried that the 3kw motor may not have been enough. I looked at a 4kw motor from Teco Australia, but it was only available as a three phase motor and the cost to rewire wasn't worth it as a just-in-case (approx. $400). Given the amp draw the VFD is showing I needn't have worried at all.

I managed to finish the ceiling duct-work (for now) this morning with 4 drop-downs in the garage. 1 drop down will be for the table-saw, 1 for the jointer-thicknesser, 1 for the band-saw and 1 above the work-bench as an all-purpose extraction point that I may make a bell-mouth hood and arm for when using hand tools or power tools that don't have dust extraction. I will also duct one more drop-down at a later stage as I plan to build a mitre-saw station along one wall so will need extraction for that. The band-saw drop down is just out of shot on the left.

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I'll need to modify the 4" ports on the Table-saw and Combination Thicknesser to 6" next. I will make a rigid duct run from the table-saw port up to the top of the table and then use a short length of flex hose to connect up to the overhead drop-down. I will likely use flex hose for the thicknesser so that changing configurations is still quick / easy.

The band saw will use a splitter box from 6" to two 4" and I plan to run one hose below and one from above connected to the blade shroud.