Connecting a Three wire inline GFCI to a 4 wire Outlet?

Hello,

Am I able to use a 3wire 240v 30a Inline GFCI, and wire it up with a 4 wire plug and connect it to a new 4 wire 30a dryer outlet?

My thoughts are that I would just be using the two hot leads and ground on the plug but I wanted to verify this idea first.

Here is the unit that I am considering:
http://www.guardiancatalog.com/Linegard-PGFI-2309-MSC-p/57090235.htm

its probably much cheaper to buy a spa panel.......

I thought that the 25' would make the price a little more reasonable. But with only 3 wires I wouldnt have a neutral for the 120v later on in the control panel.

Ya, I think I am back to using a spa panel.

Thanks!

Right that looks like it carries hot, neutral (or another hot), and ground. Do you have 120VAC available? You could just run your 120V stuff off a 120V outlet maybe. I don't know if all England is like this, but at my sister's house I believe she had 240VAC only, one conductor was neutral, and the other was hot, it wasn't a 'split phase' 240V/120V like is common in the U.S.

If you need 120VAC only for your control power, you could either use all 240VAC components, or possibly get a small control power transformer from 240VAC to 120VAC. If you don't need many VA's those aren't too expensive.