Remote control for extractors

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Thank you again and a down to earth practical consideration "would the alexa smart speaker be able to hear you over the noise of the running extractor in order to turn it off ?"
Colleagues, not sure if anyone has responded, but today i got fed up losing my remote switch. So i changed a socket to BG Smart Power (got it from Screwfix a while back for the house), then connected it to Alexa. Dust extractor now turns off and on via Alexa or by using the socket switch. "Alexa, turn on extractor" etc. The trick is that you need to bypass the NVR switch which all machines will come with (don't try if you don't know how!). Effectively its permanentaly on when plugged in, thus the remote switches noted earlier all work but also any WiFi enabled power socket.


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Not a bad shout, actually. I need to find a remote switch now.
Might be in the circuit because if the power surge upon startup. It might be better to put a relay in place of the NVR and then use any smart plug and Alexa or Google etc.
I use Alexa and an Echo 5 which also provides radio, intercom etc.
I took the NVR switch out of my fox extractor and put this inside the housing , works well so far


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Sharing for info. The recommendation in this thread for Toughleads will help me solve my own needs for a remote control.
The items below landed today. The small wireless switch is mains powered and contains relays which are not up to the task themselves but are intended to switch the power to the coil of a much higher rated contactor or Direct On Line motor starter which will handle an induction motor or whatever. They are about 3x2x1 inches in size.

The key fob remotes look simple and solid, and they offer a higher power long range wireless transmitter.



Using a 4" angle grinder and tripped the main power. Put the grinder down and went to look at the board to see what was what - one of them had tripped. Switched it back on.

A commotion from the workshop, and the grinder I'd left on was jumping all over the place taking great divots out the wooden floor :LOL:
I've been using the same relay as @Sideways for over a year with my 2hp itech extractor, it's been flawless. I removed the NVR switch and put the relay in its place so it's all neat and no live bits are exposed.

I have a hardwired in system, it wasn't expensive to do but did mean that I had to consider how it was all going to work when I wired up my workshop as some sockets are set up to trigger the extractor (so I plug tools in to those) whereas some are just normal sockets. It works really well, the only way I would improve it is that it would be good to have a 3-5 second delay to the 'off' for the extractor, just to suck up anything being thrown around as a tool spins down.

The KEMO M103N has limitations of course (specs below) so may not be suitable for your system. In mine the slave output goes straight to the extractor, which limits my whole load to 16A. For me that isn't an issue, the only tool which that affects is the planer/thicknesser and I run that with a separate chip extractor not on this system. If needed then the KEMO slave output could instead be wired to switch on a relay/contactor for the extractor which would free up the full 15A for the tool.

Of course, as with all these things, you *should definitely* get a proper electrician to do it.


Better description of what I have here:
Let us know how you get on with it @Sideways , as I am planning on getting one myself...👍
Had a quick play today.
This module will be fine.
Each module has two relays and each relay has a single changeover contact (common , normally open and normally closed). They are rated 10 amps resistive to close and 6 amps to open - different because you get more arcing when the contacts open. This is ample to operate the coil of a contactor to switch the real current.
The modules power up off mains live and neutral. No earth and not fussy about polarity.

Programming : the website has a downloadable instruction sheet which is pretty good but not exactly correct. There's only one button and one LED on the module. You press it once after powering up the module - like some sort of initialising command.
Thereafter, you press it once to enter pairing mode and you press the ON button of a remote followed by the OFF. Each is confirmed by 3 blinks of the LED then that remote is paired and operates the module. You can pair many remotes to each. Each module comes with one and I bought a spare, also the yellow long range remote.

You can clear all the pairings with a module by pressing the button 8 times in a row. This is confirmed by 3 blinks. Now start again and pair up any combination of remotes.

The action of the keyfob remotes is MOMENTARY. The relay switches only for as long as the button is held and releases immediately. Each of the on and off buttons operate only one of the two relays in the module. This is ideal for wiring the module up in parallel with or instead of the pushbuttons on a DOL starter to control a big dust extractor. You could connect a shop vac instead, but you will need a DOL starter or equivalent to boost the switching capacity and to latch the power on and off after each button press.

Interestingly, the action of the yellow long range remote is different because the button pushes LATCH the respective relays. I programmed green as the ON button and red as the OFF. Press green and the first relay switches and stays switched, press it again and it switches back. Red works the same way on the 2nd relay. Each is entirely independent so you can toggle them on and off in any order.
The yellow remote has a second pair of buttons in black. I bought two of these little remote receivers so I will program the second receiver to respond to the black buttons instead of the green and red. With the latching action, I should be able to use the second module to control two simple on/off outlets using relays but not DOL contactors to boost the current capacity. This would be great for controlling my shop vac and air cleaner which don't have big induction motors.

EDIT : it turns out the two black buttons on the long range remote are also momentary action, just like the keyfob remotes. I shall have to use the red and green latching buttons to control the shop vac and wall mount air filter, each colour as an independent ON/OFF switch. This is the sort of detail that you might expect to find in the manual but is easily figured out on the bench and the extra options it provides are a bonus over what the sales description promises.

I'm pleased with this gear. It is simple but works. The modules are small and perfectly good enough for fitting inside a more robust electrical enclosure.
Reading the company website, it is clear that they understand the proper rating of switches, cables and enclosures for workshop use. If you have any doubts in your own electrical skills, the complete, ready made solutions they sell look to be assembled from decent parts that will last and not burn out in 6 months.
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Let us know how you get on with it @Sideways , as I am planning on getting one myself...👍
This week I finally got around to wiring this up.
The modules are sold for mounting inside DOL starters, machines, any suitable enclosure and paired with a larger relay, aka contactor, to boost their current handling.
I have a box in the workshop that is really intended for use in factories. It can be configured with a great variety of outlets and I use it for that reason.

I maxed the box out with a big relay, added a 6A mcb so that I had a way to switch off the power to the module itself, and wired the relay in between a pair of 16A schuko sockets and their protective breaker. I did the same for a blue 16A CE switched socket. All of these are now remotely controlled at the same time.
The relay works with a very solid "clunk" but takes only 2 Watts once turned on.

My vac will be plugged into the schuko socket since it's made with that type of plug.
The 40 amp relay I chose is suitable for starting and stopping motors in a residential setting. If used for that purpose you must derate it all the way down to 15A and still it's design lifespan also drops by 70% to just 30,000 operations
More than enough for my/ residential needs (single phase max 2hp motor plugged into the CE socket) but these numbers do highlight how starting and stopping motors is much harder on an electrical switch that switching loads like cookers and heaters.

When choosing a contactor, note that you need one spare pair of contacts to make a no volt release / latching circuit as the radio module has a momentary action, only switching while you are pushing the buttons.


The observant will see a vfd and a 3phase socket in one photo. These don't belong together. A vfd can be damaged if you run it without a motor connected so the two should be permanently wired together.
I play with machinery and motors so this vfd is a test tool, often reprogrammed, and the plug socket connection saves me wearing out the terminals of the VFD swapping wires in and out.
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If you fancy a bit of Heath Robinson type DIY, here's what I made for my own system about 25 years ago. Recently upgraded with braided steel wire (the old string kept breaking) You pull a green ring to start, and a red to stop. There's a pair of rings by every machine. In the background of the second photo you can see a pair of the bell cranks that allow it to go round corners.The standard starter for the extract is inside the MDF box and is worked by pulling on the cables. It's very robust, involves no electrical work, and you can add a new machine in 10 minutes.
I have a similar string system but no corners involved, it's just string across the workshop down the line between where my machines go which pulls on a horizontally mounted shower switch which switches the socket to the extractor (no NVR, it's only a Camvac).

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