Minimum Run Time Switch for 5HP Cyclone Motor

Rushton

Rush
Senior User
The community wood workshop we're upgrading will have a Clear Vue CVMAX 5HP cyclone dust collector installed. As I recall, the recommendation is not more on/off cycles than about 5 per hour, so 12 minutes minimum run time.

Because this is a shared use shop, I'm concerned we won't be able to educate users to "keep the cyclone running!" So many people have never worked with a machine like this. And, being used to working with their shop vacs or some small dust collector, I'm concerned they will default to turning the big cyclone on and off like a shop vac.

Which leads me to wonder if the power relay for the cyclone's motor can be connected to some sort of minimum run time switch that can be adjusted to that minimum 12-15 minutes the motor should see. I'll be installing the standard Clear Vue power control kit (see here) and adding the dust bin full warning kit.

Thoughts? What materials would you use and how would you wire it up?
 

tvrgeek

Scott
Corporate Member
Being 220 makes it a pain. Being cheap, I might get a 110V timer (15,30,45,60 min) and have it control a 220V contactor.

I am sure, but won't know if there is a better way based on their controller until I get mine. I am sure an Arduino can do about anything.
 

Rushton

Rush
Senior User
The Clear Vue power control box operates with a 110v actuator (relay). This activates via a remote control. The 110v relay in turn activates the 220v circuit to the motor. I'll see if I can dig up a copy of the circuit diagram for the power control box.

Thanks for your reply! I am an electrical illiterate so I need the illustrated version of any instructions. ;)
 

marinosr

Richard
Corporate Member
You will want an "off delay relay". That will prevent the motor from being turned off a fixed amount of time after it is turned on. You'll have to see if there are ones that will go as long as 12m.

Are you venting to the outside, or through a filter? If outside, I'd consider your energy costs... could be cheaper to replace an entire motor than to vent 3000 cfm * 12 minutes of climate-controlled air outside every time someone wants to suck dust for 1 minute.
 

Rushton

Rush
Senior User
You will want an "off delay relay".

Thank you! I did not know the appropriate terminology. Now I know what I'm asking about.

You make a very good point about energy costs. We will be venting to the inside.
 

tvrgeek

Scott
Corporate Member
If you have 110V control, then we can hook up any 110V timer. If a 5 control, then a lot of little e-bay timer controllers.
 

Rushton

Rush
Senior User
This is sounding very promising! Thank you. I've been reading at McMaster-Carr about off-delay relays now that Richard has given me the right terminology to search for. I'll check with Clear Vue next week to see if this sort of relay is something they can incorporate in the power switch box or provide an optional kit that will integrate easily into their control system as they do with the McRabbit-designed dust bin full alarm. Failing that, it may be DIY time.
 

Alan in Little Washington

Alan Schaffter
Corporate Member
Yes, a "delay on off" relay will work as long as it is rated for the DC contactor (power relay) coil current and voltage, many are not. If you can't find one, you might need an intermediate 12V or 24V low voltage control.

You might also want to consider if there will ever be a situation where an immediate shutdown is needed- other than a duct or bin fire, I can't think of anyway- a "collected" cat, ferret, guinea pig, etc. would be toast by the time you shut down the DC. o_O If you decide it is important, then you might consider putting an emergency shut down button (normally closed contacts) in series with the "delay on off" relay.
 

Rushton

Rush
Senior User
Thanks, Alan. I'll discuss this with Paul at Clear Vue and see if he can help with a solution along the lines of what you've described.

Addition: I really like the idea of an emergency shut down button in series with the delay.
 

Alan in Little Washington

Alan Schaffter
Corporate Member
I'm not sure how the ClearVue contactor is wired. Many commercial contactors like those on the old Deltas used low-voltage (24V) control, some others use 110V, some of the cheaper ones like Grizzly and other all-in-one starter, use line voltage. The benefit of LVC is that it is easy and safe to run multiple, wired, and daisy-chained remote control stations using standard bell wire. Regardless of the voltage it is wired through spare set of contacts on the contactor and forms a locking circuit. Once a momentary, normally open, "start" button, is depressed the relay closes and becomes self-energized. A momentary, normally closed "stop" button, when depressed, breaks the locking circuit. That way, if power is interrupted then restored, the machine won't start up again on its own. So, obviously, what all of this means is, if ClearVue uses such a control circuit, an emergency stop should be inserted in series with the locking circuit.

To prevent over-cycling of the DC, another, simpler solution is to use only one DC control station and locate it at the DC cabinet not at the machines. I intentionally designed my autogate system so it would automatically turn my DC on, but not off. Instead I must go to one of several manual control stations located around my shop to turn the DC off.
 

Rushton

Rush
Senior User
This is very helpful. I feel better prepared to talk with Clear Vue about this topic. I may well be that the best solution will be the one you implemented for your shop as outlined in your last paragraph. It can certainly work here, together with a BIG SIGN.
 

McRabbet

Rob
Corporate Member
Rush,

I think your goal of maintaining fewer start/stop sequences to avoid motor overheating is good, but the strategy of forcing an artificial duration of 1/5 of an hour to keep the cyclone running regardless of actual demand is flawed for some key reasons. I'll outline some examples.

First example, a user wants to use one or two of the connected tools (e.g. the jointer followed by the planer) to mill some lumber. It takes him ten minutes to accomplish his tasks, so he doesn't care if the cyclone runs for another 2 minutes and then shuts off. Meanwhile, another user wants to use the planer and waits for his colleague to finish before he starts his runs of five boards -- unbeknownst to him (or her), the cyclone is on a countdown timer and it stops the cyclone while his stock is just a short way into the planer and he has taken a hefty pass that ends up clogging the machine and damages his stock.

Second example has a user that has more than 12 minutes of work planned and the cyclone doesn't give him enough time to complete his tasks, so he restarts the cyclone as soon as it shuts down, potentially overheating the motor. Does he need to wait for a cooldown period?

The issue at hand is motor overload due to heat buildup created by repeated start and stop sequences. The 5 HP Leeson motor is designed for continuous operation and if you monitor the amperage draw, you'll quickly realize that startup causes the peak demand and produces the majority of the heat generation. Once running with one or more gates open, the motor will draw less than half the amperage than at startup and it can run for hours without overheating. Start the cyclone up when the shop is opened (use a key switch next to the entrance or next to the cyclone closet) and shut it down when the last user leaves the shop. Letting it run won't harm it and the electric bill won't be that drastic. The only downside of this strategy is when nobody needs dust collection and it runs without need.
 

marinosr

Richard
Corporate Member
You might also want to consider if there will ever be a situation where an immediate shutdown is needed- other than a duct or bin fire, I can't think of anyway- a "collected" cat, ferret, guinea pig, etc. would be toast by the time you shut down the DC. o_O

A fire in the separator? Admittedly hard to imagine how it happens, but I've seen chuckleheads do some amazingly stupid stuff at a community woodshop.


Start the cyclone up when the shop is opened (use a key switch next to the entrance or next to the cyclone closet) and shut it down when the last user leaves the shop. Letting it run won't harm it and the electric bill won't be that drastic. The only downside of this strategy is when nobody needs dust collection and it runs without need.

This is the better suggestion for sure, but the big downside is that the DC is the loudest tool in the shop, maybe meaning that hearing protection would be recommended/required all the time. OSHA requires hearing protection at 85dB continuous, but the CDC recommends it above 70dB. So considering some serious sound insulation may be a good idea then. It would be a good idea anyway.

I've never worked in a multiperson shop with the DC inside, so admittedly it's hard for me to envision. I've only dealt with cyclones sitting outside and venting outside.

If power tool usage is intermittent, I think your problem will be best fixed by hanging a large sign above the DC switch (or a large sign hanging as a fob on any remotes... This will also keep yr remotes from walking off.) "Don't turn the dust collector on and off for every cut. It's bad for the motor." A little human engineering is probably better than a lot of electrical engineering.

Edit: Just saw your other thread on the shop layout etc. I was picturing a much larger facility with more users. Looks like you have space for 3 people max. I imagine it would be unpleasant to be in that small shop with the DC running continuously, or even running for 12 minutes after someone makes a single saw cut. IMO that would be my overriding concern. A good Lesson or Baldor motor is hard to kill.
 
Last edited:

chris_goris

Chris
Senior User
To McRabbets point, you may want to investigate leaving it on continuously while the shop is open. It may actually use less power (if the shop is regularly fairly busy) than turning it on and off. This would also be alot easier on the motor long term. Not to mention "where is the keyfob"?????. Maybe Stuart Kent will chime in here or others with multi person shops.
 
Last edited:

Bas

Recovering tool addict
Bas
Corporate Member
Not to mention "where is the keyfob"?????.
Maybe get rid of the remote and put a physical switch near the DC closet. Having to walk all the way over would discourage people from turning it off too frequently.
 

Rushton

Rush
Senior User
These are all excellent suggestions and considerations! Thank you.

Rob, your example scenarios were very helpful to me envisioning how such a delay timer might adversely impact people in the shop.

We will plan to move forward without a delay timer and instead rely on forcing people to walk to a switch at the cyclone to power it on and off. As suggested, we'll apply a little social engineering to the solution.

Noise is the BIG consideration. This is why we're planning to do as much as reasonably possible to sound isolate the system in its closet. (This will be another posting when I have some design sketches ready for comment.) I'd really like to get the cyclone into another room, but our options are limited (perhaps non-existent) in this regard. Having the cyclone inside the shop is the reason I expect not to have it operating all day long. If it were in another room, or outside, that would be a clear solution. But not with it inside the shop.

And, yes, this is a small shop. Two people can work quite comfortably, and three is pretty much the limit. It's great when there's only one person! This is a situation where we are simply happy to have any space at all.
 

Alan in Little Washington

Alan Schaffter
Corporate Member
I would like to follow-up on Rob's discussion. As to turning the DC on and off, remember starting is hardest on the motor. The next biggest stressor is running the DC with all gates open or the worst, but not likely to happen, no pipe connected to the intake, which make the motor work the hardest. This is kinda counter intuitive, but the least stress on the motor is having it run with all blast gates closed- no flow no work. So, really the only issues to me running the DC almost continuously are the noise and how the running DC impacts the shop climate. With the DC located in a sound insulated cabinet (suitably vented to ensure the motor doesn't overheat and possibly a small cooling fan to help the TEFC design), and filters to recycle the air, you have hopefully remediated those issues. The DC will add some heat to the air but if the shop is air conditioned, it should be easily managed.

However, since it is a group shop which can accomodate 1 to 3, and possibly as many as 4 people operating machinery intermittently during the same shop session, the biggest problem I see is people (of varying skills and appeciation for dust control, etc.) forgetting to open and/or close blast gates! Even a Max will have a hard time drawing adequately from 3 or more machines. So, short of getting too complex with a DIY system using current sensors, PLC control, electric or electro-pneumatic blast gates, etc.etc. and unless you are willing to spend big bucks on an iVac system you'll need to do a couple of things- Conduct some sort of DC training and qualification and make it easy to turn on the DC, locate, determine the status of, and operate the gates, etc.

Having said that, a system like mine really might be ideal in your situration- where when any machine is turned on the DC starts and the individual blast gate opens. When the machine is turned off only its blast gate closes- the DC must be turned off with a manual action.

And finally, I'm sure Rob would agree- with the DC in a closet, and multiple users (who are not responsible?) you will need a high dust alarm or circuit to prevent overfilling the dust bin and clogging those expensive filters! "But I thought Bill just checked it?" Wasn't Tom supposed to empty the bin?"
 

Willemjm

Willem
Corporate Member
The five times per hour 12 minutes minimum run time sounds totally unreasonable for a respectable design?

When an induction motor starts, the starting current is much higher, resulting in a proportional heat increase. However, during running it should cool down within a couple of minutes. For a normal wood shop operation these times should never even be a consideration. Further, in industry situations (automated feed conveyors for example) where a motor stops and starts continuously we would allow an operating temperature of up to 90 degrees centigrade and protect the motor with a thermal overload.

If the motor is that much under rated, I would suggest fitting a thermal overload breaker and if all the blast gates are open, I would be concerned that it may overheat while continuously running.

I have an inexpensive Grizzly 3hp, been running it for 14 years, never bothered about how many times I stop and start it.
 

Charles Lent

Charley
Corporate Member
You might also want to add an automatic shut-off when the shop lights get turned off. This, to prevent anyone from leaving the unit running when they leave for the day. My air compressor is connected like this. I can turn it on and off with buttons, but it will shut off automatically when I leave the shop and turn the lights off.

Charley
 

Rushton

Rush
Senior User
Alan, the automatic circuits you have built into your shop system would be ideal given the variable knowledge level of multiple users. I like that your circuit is set to turn on the DC but not turn it off. That's a perfect design choice in my opinion, particularly good for moving from one machine to a next machine during a working session. I suspect a fairly simply low voltage switch arrangement could be designed to accomplish this much, even if we haven't automated the blast gates' opening with the machine starting (which would, of course, be even better!). More research needed on this!

As you point out, noise is the only consideration for not simply running the cyclone continuously during a work session. And to this point, I have gotten permission to use that adjacent storage room for locating the cyclone. The only thing we need to sort out, as a matter of courtesy, is how the noise of the cyclone in that location may impact a couple of people with offices right down the hall from where the cyclone would be located. Sound insulation would be added, of course, just as we would if placed in the main shop. I'll be working on an alternate floor plan and duct layout to see how this might work. We'll also run some noise tests using some power equipment to simulate the noise from the cyclone as heard in those offices. More to come on this.

Willem, the 5HP Leeson motor in this system will run quite happily all day long. No problem there. And it is certainly not underpowered. My concern is to prevent the motor from being short-cycled by people used to using shop vacs, with the repeated startups putting excess stress on the capacitors. Starting up that 16" impeller is a load. Best for the motor if we turn it on and let it run, as you suggest.

Charley, great suggestion! We plan to configure this the same way you did. Power to the cyclone's activator relay goes off when the lights go off.

Edit: Forget to address this suggestion from Alan about a dust bin full alarm. Yes! I plan to include Rob's dust bin full alarm that Clear Vue now sells. Had it in my former shop with just me as the user and will definitely add it here with multiple users. I also plan to build a lighted view port into the dust bin lid so we can visually check levels before the alarm sounds.

Edit: And forgot to address Alan's additional excellent recommendation to provide training to users about working with this dust collection system. We plan to develop a full certification checklist for people who wish to use equipment in the shop. To use a given piece of equipment, the prospective user will have to pass a certification check-off that they know how to use that machine safely. Using the dust collection system correctly and safely will be part of the checklist.
 
Last edited:

Premier Sponsor

Our Sponsors

LATEST FOR SALE LISTINGS

Top