EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: alanambrose on September 08, 2021, 10:27:26 am
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Hi,
For a CNC - I want to switch an external fume extractor using a low voltage relay or similar already on on the CNC board. While I can mock up something myself I would prefer something off-the-shelf and CE-marked as this has to be given to customers. So, has anyone seen a sort of contactor-in-a-box (preferably with UK or IEC plugs / sockets) switched by low voltage or (less useful) by a USB signal?
TIA, Alan
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Be carfull, a CE marked product is not necessarily a good product. This marking does not require testing the product by a control organism. It is a self - certificate. The seller simply certifies that it meets certain standards. Unfortunately, I know a lot of products which have a CE mark but which do not respect the standards :palm:. The only risk for the seller is in the event of a filing complaint
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You'll be lucky! I think youd be best to farm out your nearest panel builder or "box builder" with ISO9000 acreditation.
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Hi Alan,
I'm sure one would be hard put to locate an off-the-shelf 'motor control box' comprising an MPCB, a contactor and an industrial socket.
I suppose you would have no choice but to roll your own!
Nandu.
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OK for anyone else looking for this kind of device - there's at least one UK supplier:
https://www.canford.co.uk/Products/42-6701_CANFORD-OPTO-SWITCHER-Mk.2 (https://www.canford.co.uk/Products/42-6701_CANFORD-OPTO-SWITCHER-Mk.2)
Will switch 6A. Used e.g. in the AV industry to switch on the 'Live' light in a studio. Will support either a NO switch or a +V signal.
There's are also RS232-controlled switches for power control in server rooms.
Alan
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And another, also CE-marked:
https://shop.stepcraft-systems.com/Switch-unit-SE-2300-for-electric-consumers (https://shop.stepcraft-systems.com/Switch-unit-SE-2300-for-electric-consumers)
Alan
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You would be better off consulting with a local electrician / electrical engineer. Here is the USA such an installation may require motor overload protection and even a disconnecting means. The socket might pass as a disconnecting means but again this can become an issue of the local code. Unlike a manually controlled tool once it is operating without a operator there is often a need for overload protection.
You might be better off supplying a 24VDC signal for use by an electrician to hook up a proper relay. In other words let the customer make sure the installation is proper.
An alternative is to have your control system in a decent sized panel box with space for an internally mounted contractor. Even here it is problematic because you will never know what type / size extractor they will want to connect to. In the end you either offer your own solution or let the customer install whatever he wants.
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Hi,
For a CNC - I want to switch an external fume extractor using a low voltage relay or similar already on on the CNC board. While I can mock up something myself I would prefer something off-the-shelf and CE-marked as this has to be given to customers. So, has anyone seen a sort of contactor-in-a-box (preferably with UK or IEC plugs / sockets) switched by low voltage or (less useful) by a USB signal?
TIA, Alan
any ssr in a box will do, or any classical contactor. just by one from uk, farnell or whatever you like, it will be CE certified for sure
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Hi,
For a CNC - I want to switch an external fume extractor using a low voltage relay or similar already on on the CNC board. While I can mock up something myself I would prefer something off-the-shelf and CE-marked as this has to be given to customers. So, has anyone seen a sort of contactor-in-a-box (preferably with UK or IEC plugs / sockets) switched by low voltage or (less useful) by a USB signal?
TIA, Alan
any ssr in a box will do, or any classical contactor. just by one from uk, farnell or whatever you like, it will be CE certified for sure
Most SSRs are just components ( exposed terminals etc.), and not suitable for supply to end-users.
Once you put it in a box, you assume responsibilty for things like creepage/clearance, flammability of the box etc. and different CE standards will apply.