240 vac Relay cct

ok, transistors, driven by PIC microcontroller outputs, drive 12v through each relay primary, which then switch each of the two 240v devices.

I think the kettle connectors are quite neat. One is the normal mains lead in, and the two others are output types, which can be plugged in as needed (can use one or other, or both together), and saves me having to worry about clamping hard-wired leads in to the enclosure box.

Does that help?

Cheers, Mark

Perhaps a tad more info on the cicuit ? I.e two 240vac coil relays switching 24v or a 240 to 24 tranny that feeds the relays which are switched externally etc etc. Pretty hard to help without more details although the "kettle" connectors doesnt sound really "pretty" :-)

-- Regards ..... Rheilly Phoull

Yup, so your main concern should be the safety aspect of the mains wiring. Personally I would use a metal enclosure that was securely earthed by bonding the incoming earth lead to it, using a dedicated screw with flat and star washers. All outgoing earths would then be attached above this with their own nut and washers. It occurs to me that by "Kettle connectors" you mean IEC type plugs and sockets (3 small oblong pins all aligned ) whereas I am perhaps of another older era where a "Kettle Plug" was called an "Appliance connector" and are a lot more bulky and less reliable. I would agree that IEC connectors would be good. I do not have knowledge of the codes for UK wiring so hopefully others can help you there. You would also need to arrange for the interface wiring to seperated to avoid potential danger should the signal wiring become connected to the mains. A little care with wiring the relays should handle that although if the 24vdc can be bonded to earth any mishaps should blow the fuse in the

240vac circuit. Consider the load you are supplying and if its small and the source vac circuit has a large fuse it wouldn't be a bad idea to mebbe have a suitable fuse mounted in the enclosure. Perhaps another approach would be to use thyristors instead of relays but they would definately need to be in a metal enclosure to hold down the EFI. Best of luck with your project.

-- Regards ..... Rheilly Phoull

Thanks for the advice.

I'll go for a metal enclosure, with the earth leads connected. I'll have to think of a way to segregate the user switches and buttons so that they can't get touched by any loose mains leads.

btw. IEC type plugs and sockets is correct.

Cheers, Mark