Hi Martin,
This came in kit form and I built it. The relay used for switching is rated at 125v AC and 15A (therefore 1875 watts) but if this is not enough, you (or me I should say) could add a slave relay that will take any wattage you like. (yes the power line is what this switches)
BUT there may be a problem with adding it to your machine. I bought this to remotely operate my water-fed pole trolley system. The problem is that when it switches the pump on, the pump generates interference which then blocks the transmitter signal. (so you can turn it on but not off again).
I dont know anything about your machine, but if it has an electric motor, this kit will be of no use - you will need an FM system (this is AM) so that it isnt affected by interference. I know where you can get them if you need to.
I was using remote controls from Wicks Building Supplies but now thy have altered them to only take 1000watts.
If you already have a remote that works, but the relay isnt rated to switch the level of power you need, it is very simple to add a slave relay. (the remote is used to switch a small relay, but the small relay is used to switch the power relay) If you need any help with that let me know.
For example, this 12v power relay has a contact rating of 10A @230 VAC = 2300 watts and only costs £4.99
From Maplin:
http://www.maplin.co.uk/products/module.asp?CartID=040426201636571&moduleno=26064-Philip