Kev, It looks to me that you are essentially boxing up a commercial unit and this will still have the drawbacks of the core unit.
By this I mean the trigger current will be limited by the makers and more importantly the output switching capability will be limited to less than many dust collectors need to start them.
It appears from your glib calculations from current capability and watts, that you are not aware (or are hiding) the complexities of AC circuits, power factor and most seriously inrush starting current. Forgive me if I have misjudged your knowledge. I do not set out to offend.
If you want a truly useful product for the widest range of applications, the input needs to have a tolerance for short term currents of 30-40 amp and if you can't manage this, suitability to have a current transformer fitted on the input so that is can. In this way your unit will comfortably rated for big saws and planers up to say 3HP and running on 16/32 amp supplies. On the output side you really need a volt-free (ie isolated contacts) and a 3 wire interface to feed to DOL starter contactors that many of us have with our dust collectors. For these purposes the current rating can be very low as you are only driving the starter coils in the DOL starter. For use with vacuum cleaner type collectors, relay type contacts with 16 amp rating will be fine.
So thats the requirement side of things.
Then as Noel and others have mentioned there is the product liability minefield. Simply getting approvals does not remove all responsibility from the vendor. Maybe consider the relatively small outlay for the safety buffer of a limited company?
Finally what I was trying to allude to earlier are the commercial sensitivities of this forum. This forum covers all its costs (and maybe? a little more) by taking advertising and to be fair to their paying customers, they don't like members effectively getting free advertising by marketing their products in the forum pages. This is quite fair and reasonable, it's Charley's site and the moderators work hard too keeping members within the rules they set out. There are other forums where you might get away with marketing stuff you make but they have far less footfall than in here which is certainly the biggest in UK. Who know their advertising rates might be worth it. They used to have something like the ability to pay for "featured posts" - not sure if that is still offered.
Be aware that all the forums cost money to run and could reasonably ask for a contribution to promote your product.
I hope you find what I've written to be constructive - it is genuinely meant that way and I wish you luck with your venture.
Bob
