Contributor
That would work if you got the Delta 5HP motor (possibly) as long as the Delta impeller was not too big. With Delta 5HP, the Static Phase Convert would give you a 3.3HP result. This wouldn't work if you got the Powermatic motor, but VFDs are not that much more expensive.Originally Posted by Jeff Roltgen
Member
What size impeller do you recommend? HP means vey little, it could be driving a 12" impeller which is useless.
Chris
Everything I like is either illegal, immoral or fattening
Member
In general, an increase in HP is necessitated due to the presence of a larger impeller. For instance, the Murphy Rogers has a 16" impeller with a 9" inlet. 2,400 free air cfm, as I see is similar to a current 5hp3ph model offered by Grizzly. At half the price, their next model down is 5HP single phase, yet still spinning a reasonably larger 15" impeller from the dreaded 12".
I understand your contention that HP number does not necessarily equate to a better machine, especially in this day and age of creative license in marketing via specs alone. Look at same pair of Griz units compared above. $4k unit boasts 2,184 cfm (@ 1.9 IN SP), yet the model half the cost and smaller impeller is boasting almost double, at 3,961 (airflow capacity). Ain't shopping fun!
If you have any way of viewing a contending machine in person, you may be shocked at the sheer mass of a 5HP 3ph setup. These units are made to run incessantly, need almost no maintenance, and I picked up this old one for almost free, which included 8 and 9" trunk runs of spiral pipe. Many times, due to 3ph designation, they are promptly dismissed, making for dismal resale value.
As we've all discussed here, you now know a simple $80-$230 static PH converter or VFD is the secret to making one run, so take advantage if you can, and see if one of these old buggers is looking for a new home.
Last thing I'll mention, yet of great importance: If you land a unit of this size, you really do need 8-9" main trunks, reducing to 6-5" branches as you reach 15-20 ft from DC, reducing to 4" only for the smallest machinery. In other words, not advisable to connect a system of 4" duct to the mouth of an air moving monster like one of these - you'll likely reduce it's performance to that of a 3HP 12"impeller at the 9" to 4" reducer, = nothing gained. (Never underestimate the power-foiling capabilities of an under-sized duct. )
Still, those old units are around, and many times sitting with a pile of spiral duct...
Bet you can do it!
Jeff
Contributor
Some notes to make on these comments. A static phase converter will use a capacitor as a "helper" on the 3rd leg of the 3 phase output to help start the motor. Once the motor is started, the capacitor cuts off and the motor continues to run using only 2 of the legs from the 220V single phase power source. This means that the motor is being pushed using only 2 of its 3 windings. That's why it we say the motor will only produce 2/3 of it's rated power when used with a static phase converter. You can do this if you size the motor higher than what your requirements are. If you need the entire HP of the motor, a VFD is a better solution.
For example, let's look at the Delta 5HP. If it is the model 50-765, the only detail I have found indicates this uses a 13-1/2" impeller:
https://www.hingmy.com/site/content.php?p=732
I think this is rather small for a 5HP motor, but it works. It's definitely not going to pull the 4800 CFM that is advertised for it. It is likely going to be around 1200 true CFM once everything is hooked up. In this instance, it's perfectly fine to use a static phase converter since the impeller and CFM load is not going to reach a high amount. Running a 3.2 HP motor in this situation is gong to be just fine.
However, when looking at the Powermatic 3HP dual bag mobile dust collector, the impeller is actually pretty large for a typical mobile collector (it's 14"). I would not use a static phase converter here because it would only yield 2HP. I have seen Bill Pentz commenting on HP size of motor and he stated that 3HP would be run at the edge of it's capability with a 15" impeller. That's why he recommends a 5HP for a larger impeller (such as 15" or 16" Clearvue dust collector solutions). While a 2HP motor might run a 14" impeller okay, I think it's possible you may overheat the motor some (depending on situation). A VFD is best in this situation to run the motor on all 3 phases.
With regards to duct size, it is completely true that 4" main duct and 4" drops are bad. However, going too much in the opposite direction can also be bad. If you size your main duct too large, you actually will not have enough air velocity to pulled the dust through. You really have to do calculations on your system if you are going to max out the size of the main trunc. If you have 6" drops that connect to dual 4" inputs and your main trunk is 8-9", then what happens is the air slows down when it encounters a larger area. The CFM does not change, but it's now traveling in a much larger area. While you might get enough velocity in your 6" drop to pull the dust up to the main, if your main is a giant 9", then the air velocity in the main will not be enough to pull the dust all the way into the cyclone. The dust will settle and build up until the main is completely clogged and this creates a fire hazard. A lot of you guys have experience with cabinet saw dust collection. You know how all the dust is never sucked into the hose and starts to pile up in the bottom of the cabinet and you have to clean it out every so often. Same thing happens with a main trunc that is sized too large.
Even with a big 5HP collector with a 15-16" impeller, if you are only going to use one tool at a time, then I would size your main trunc at 6". If you go up to 7" or 8" main, then you need to have at least two 6" blast gates open to create enough air velocity in your main trunc. A 7-8" main trunc is good if you have the capacity and want to use two tools at the same time, but you HAVE to have two 6" drops completely open.
Contributor
I've built 3 "shop built cyclones" and can offer this . A 2 HP Grizzly blower ( 12 3/4" impeller ) is the smallest that I feel is worth the effort to build . You MUST design and install ducting that will utilize all the CFM you've got . Your not going to be happy otherwise- you can't overcome much at that smaller size . If a 4 HP or 5 HP w/ tall bags was found , now you have the blower/ impeller that you can get very good results with . They are scarce for sure , lots of 2 & 3 HP units out there , and the Grizzlys will have the same impeller (12 3/4" ) . My small system was enlarged on the exhaust and intake sides , trying to get the most from it . Its good in my small shop , but it can't compare with 15" or 16" impeller in a big DC . My decisions were budget driven .
[OP]
Contributor
My duct work setup is going to change too in this new design. I’m going to take out a huge right angle in the main trunk and mount the dust collector somewhat in the middle of a wall so I can have a single trunk go the length of the shop. That will leave me with a ~15ft long 6 inch trunk line. I have 4 branches off of it, from 6 to 16ft long (the 16 ft is for my least used tools). Each branch is also 6 inch ducting. Then my tool drops are mostly 4 inch flex hosing (planer is 5 inch flex) from 3 to 8 ft long.
I’m in the Seattle area and … everything is expensive here. Used tool deals exist, but they’re not great. Especially if I’m not up for waiting for a long time. I found https://seattle.craigslist.org/skc/t...505168490.html which is a 3HP, 3PH powermatic with the 14 inch impeller. This might be my best option, especially to get something now.
Seems like I’m hearing that i should leave my trunk and branch lines at 6 inches?
Contributor
What about running them in series? Ia ssume air flow will stay about the same but pressure will increase. I have heard of using a blower to supercharge an air compressor.
Bill D.
Member
From this last post, sounds like you're in reasonably good shape for your system. I'm simply indicating, if you end up with a DC that has an inlet more than an inch larger than your current 6" trunk plan, I would urge you to run at least 8-12 feet of a trunk that matches inlet size, then reduce to your 6".Seems like I’m hearing that i should leave my trunk and branch lines at 6 inches?
Aaron is correct about over-sizing, but that doesn't appear to be the risk here.
These larger machines rely on volume. Try adapting your 2" shop vac hose to a drop on your DC system. Certainly, your current dust collector far outpowers your shop-vac, and will easily out-perform that screaming little plastic drum, right? You'll actually find the shop vac has higher velocity and picks up more with that small hose than your DC can.
Difference is the little one relies on velocity and the big dog relies on volume.
Don't choke the big dog.
jeff
Member
Most people think a dust extractor is working efficiently if the visible debris is collected and leave it at that and if that is your aim then a broom can be used for a lot less expenditure and money. If you want to collect the fine dust small DE's won't do it and a lot of effort and money is needed. Using small impellers and a cyclone makes the situation worse because cyclones by their nature have to slow down the air flow to do their job so the air flow falls. When we talk about fine dust we are talking about the stuff you can't see and just because the big debris is in the bin does not mean the fine dangerous stuff has been captured because you need a lot of air to do that.
I am sure that most WW think that because they collected all the big stuff it is job done but that is not the case and specifying DE's by horse power does not give any indication of the air flow capacity of the system. Any CFM air flow quoted for most DE's is fairy tale rubbish, you need to know the impeller size to gauge if the quoted figure is even remotely true. In the recirculated systems that are used in cold climates every bag collector ever made with no exceptions all leak fine dust so any mobile bag style DE should be isolated from the work area to prevent the dangerous stuff being leaked back to the work area. Unfortunately your health depends on how well the DE works at removing the invisible dust from the work shop, the knowledge is out there to ensure you get it right but few WW's understand that a clean workshop is not necessarily a healthy one.
Chris
Everything I like is either illegal, immoral or fattening
Contributor
Did you make any decisions yet? That Powermatic looks really nice and I think you won't be able to get anything better. It's essentially brand new. Just so that you know, the cost of the actual motor on that Powermatic dust collector is $712 (that doesn't include the cost of the impeller/case unit):
https://www.mmtoolparts.com/powermat...r-pm1900-105-3
A Baldor 3HP 3-phase motor is going to be somewhere between $800-900 (Clearvue sells the bigger 5HP Baldor 3 phase for $950).
If you get that 3-phase Powermatic and match it up with a VFD, one of the benefits is a soft-start (essentially a slow start - recommended 10 second startup). This puts significantly less stress on the motor windings as there is a lot of resistance with air and high current draw to ramp up the motor. This means less heat generated and you can do more stops/starts per hour (Clearvue recommends only 4 stops/starts per hour on a single phase motor). Plus, you can easily wire in an eMylo relay to the VFD for a remote keyfob.
You could go with a 5HP single phase motor with a larger 15-16" impeller from Clearvue, but it will probably cost you at least $1000 at that point. You need a high power remote relay to switch this on/off. Clearvue sells their remote power switch box for $250 (you might be able to find something else cheaper).
[OP]
Contributor
Ah, yes, I did end up buying the powermatic 3HP 3PH model. It was new in box, but the box was beat up. The guy runs a ‘scratch and dent’ store in Auburn, WA. The amount of JET, Powermatic and other random stuff he had was amazing. Picked up a Lapond VFD for it as well and an eMylo remote. Figured the remote settings for the VFD easy enough. Everything is sitting in a storage shed while a contractor works on my garage roof - hoping to put it all together in a few weeks.
I’m *hoping* to take my 2HP jet blower, mount it to the frame of the powermatic (that I don’t need) and will sell it on CL. Maybe I can only be into this Powermatic motor for a few $100.
Contributor
let us know how this ends up , I'm eager to hear .
Member
You will never regret going to a 3 phase DE, how hard is it to have a 240V single phase outlet in a workshop in the US?
Chris
Everything I like is either illegal, immoral or fattening
Contributor
If you are talking about home garage / home shops in the U.S., it is standard to have 230V single-phase run to the main power panel in homes (using two opposing 115V legs). Most outlets in homes are 115V, but you do have 230V lines for stuff like stove, oven and dryer. Sometimes you can find a 230V outlet in a garage, but most of the time you have to have an electrician run a 230V line from the main panel. Alternatively, some people go as far as putting in an entire sub-panel for 230V workshop tools.
If you are talking about commercial shop locations, most all definitely have 230V single phase. Many have 230V 3-phase and even 460V 3-phase.
(NOTE: when referencing power in the US, the standard is to call it "115V" or "230V", but in reality, many people are getting somewhere between 120V and 125V actual in there houses - which translates to 240V or 250V actual when using both legs).
Last edited by Aaron Inami; 07-31-2022 at 10:19 PM.
Member
Aaron, thanks for the correction and yes I am talking of the average home workshop. Australia has a domestic single phase 230V supply so plugging in a VFD and using multi voltage 3 phase motors is a simple exercise and was the reason 3 phase Clearvues was all that we sold. Our 3 phase is 415V and even then we use a VFD for speed control because it is far kinder on the mechanical bits as well. Clearvue cyclones are no longer sold here due to cost increases mainly in freight which has simply gone mad. It took me a long time to realise that 3 phase was the best way to run a dust extractor simply because I had never used a single phase unit at all.
Chris
Everything I like is either illegal, immoral or fattening
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