Thread: Auto On Dust Collection Options

Need some help wiring the new switch, please see my new thread:

Need Help: Dust Extractor Switch Conversion (Electrical Wiring)

Originally Posted by EagerBeaver71

I want my dust collector to automatically turn on when I start my Tablesaw or other machinery that its connected to. I've seen the iVac system but it seems abit pricey for what it is so I thought I'd ask the WWF for any alternatives or suggestions.

This may be of interest, a bit on the small side, but has the auto on feature that you mention.

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It's just a moveable set up for a ROS with a cyclone and a shopvac, something that will roll around the workshop as I need it.

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I didn't realise when I bought the shopvac that it has the feature you can see in this pic. There is a power outlet that the ROS plugs into on the actual shopvac, without needing another adaptor or power source, and the switch has two positions. O is off of course, and the I side turns on the shopvac by itself. But with the ROS plugged in and the switch set to II, nothing happens until you start to use the ROS. Then, after a slight pause, the shopvac kicks in as well! How good is that!

If a piddly shopvac has this feature then why not bigger setups? I suppose they would need to be built in to the suction unit?

Originally Posted by burraboy

I didn't realise when I bought the shopvac that it has the feature you can see in this pic. There is a power outlet that the ROS plugs into on the actual shopvac, without needing another adaptor or power source, and the switch has two positions. O is off of course, and the I side turns on the shopvac by itself. But with the ROS plugged in and the switch set to II, nothing happens until you start to use the ROS. Then, after a slight pause, the shopvac kicks in as well! How good is that!

If a piddly shopvac has this feature then why not bigger setups? I suppose they would need to be built in to the suction unit?

The primary issue with operating with a remote sensing unit like a shopvac is running the full rig (shopvac plus tool) from a 10A outlet. The shopvacs are typically 1000-1200W, so use around 50% of the nominal rated capacity of the outlet. Adding a 2HP load such as a fairly low powered table saw or router means that the system (shopvac and tool) will exceed the ratings of the shopvac plug and cable, and the outlet supplying them.

Ideally, you would want the shopvac and the tool operating on separate circuits to keep everything within limits. This is not an issue for a ROS as the sander would normally be rated below 1000W, and the combination below 2400W.

In addition, it is highly recommended that the dusty/vac system continues to run for some time after the dust creation machine shuts off to continue to collect airborne particles that are still circulating in the work area, and most of the remote sensing shopvacs do not have that sort of facility.

Originally Posted by EagerBeaver71

I can't think of any reason to have a safety feature like that on a DC, other machinery like table saw - planer - thicknesser, hell yes but not a dust collector.

I would consider having an NVR on a dusty as secondary safety rather than primary safety. Consider the possibility of a dusty with a toggle switch for power control, in a situation where there is a mains outage for a couple of hours or more. Users may opt to pack up and leave the workshop thinking that everything is safe as all machines turned themselves off when the mains went out. Power comes back up in an unattended shop and the dusty with a toggle switch starts up and continues to run until someone comes to stop it. Maybe OK if the shop is someones garage beside their house and they hear it and come out to turn it off, may not be OK if it is an industrial setting with no one on the premises, or a shop some distance (20m+) from the owners home. What if a block or something similar comes down the line and jams the impellor stalling the motor and ultimately causing the motor to catch fire.

I see things for moderate power machinery heading in a specific direction, where powered hand tools generally have trigger switches and single phase powered machinery has some form of NVR, while 3 phase machinery has contactors (inherently NVR) and overcurrent detection to provide a higher level of consistency between units and better safety margins.

Avoiding damage to flesh and bone is an element of safety planning, but it is far from the only element. For what you are wanting to do, I would be leaving the NVR switch in place and installing whatever you choose as a remote system between the NVR and the motor. That way, you retain the protection that the NVR provides as secondary safety, but retain the convenience of remote control of the dusty at the same time. Just make sure that whatever you select as a remote module can handle starting the motor in the dusty over many stops and starts, a lot of the cheaper units around are not intended for starting inductive loads like motors on a regular basis, and as suggested, tend to fail within a year or so, primarily because they have welded the switching contacts closed, or severely burned them with arcing.

Originally Posted by malb

Maybe OK if the shop is someones garage

Hi Malb, Thanks for the advice. My garage is my workshop.

Originally Posted by malb

I would be leaving the NVR switch in place and installing whatever you choose as a remote system between the NVR and the motor.

I've already installed the new toggle switch

Originally Posted by malb

That way, you retain the protection that the NVR provides as secondary safety, but retain the convenience of remote control of the dusty at the same time.

Or I could just stick to my usual safety routine of unplugging everything before leaving the garage.

Originally Posted by malb

Just make sure that whatever you select as a remote module can handle starting the motor in the dusty over many stops and starts, a lot of the cheaper units around are not intended for starting inductive loads like motors on a regular basis, and as suggested, tend to fail within a year or so, primarily because they have welded the switching contacts closed, or severely burned them with arcing.

Yep, good advice, I'll be shopping around.

If you want a system that just works day in day out get a greengate by ecograte. Its now a professional system but there are small systems suitable to home workshops. I have been using the system with a few upgrades for over 20 years without a problem. Even the 4” original plastic automated blast gates still work without problem. Most of my gates have now been upgraded t 6” metal gates and my whole workshop is automated. Never have to think- switch on a machine and the dust extraction is connected and continues to run for the specified time to clear the ducts. JUST SUPERB. Its expensive and has to be imported from USA but you get what you pay for. Theres ecogate and then theres the rest.

Why DCs have an NVR.

In the early days when I first joined the local mens shed we had an old school 2HP DC that had no NVR - just a plain toggle switch. This DC was often hooked up to different machines so occasionally the bit of flex used for the air connection was left laying on the floor. One day someone turned on before hooking it up and it sucked up a piece of rag and started making a racket so the chap turned it off at a wall socket with two outlets and started to try and work out what had happened. The DC user took the cover off the DC impeller and was just about to put his hand inside the impeller when another shedder came along to use a machine plugged into the same wall outlet but accidentally turned on the DC switch. The impeller with even a 2 HP motor will have enough torque to easily take someones hand off. That DC was one of many I replaced the switch on.

Also it is possible to use a 2HP table saw and a 1200W vac from the same 10A socket - I did that for a number of years. The 2HP table saw will only draw its full 2HP (1500W) when starting up or when fully loaded eg ripping a 3" thick board. Likewise the 1200W vac.

When a 2HP TS starts up it will draw as much a 30A for a brief period and then settle down to draw about 2A free running. Then you can start the vac which will draw maybe 20AA briefly and then settle to about 1A.

When these things start up ,the higher start up currents should not trip the breakers as even if the current exceeds 10A most breakers are designed to take more than a single sockets rated currents for a short period of time as represented by a machines start up
In addition most 10A lines are usually connected to a 16A breaker.

OTOH it is possible to flog something like a 2HP TS so that it draws more than 1500W eg hard wood blunt blade and too big a feed speed - if this is done continuously then the breaker will tip or the TS motor will over heat and cut out. A stock DC/vac is far less likely to do that as the impeller will simply cavitate and that will actually draw less air and hence much less current. To make a DC draw more current a large inlet pipe and/or impeller is needed.