Shower Priority Switch?

[gbandera]

Hi,

I'm looking to install two instant water heaters, and to prevent overloading I'm looking to use a Shower Priority Switch so that only one heater can draw power at any given time.

Problem I can only find one on the Internet (the GE Unit) from one supplier so I'm guessing there is a more common name for such a device?

Can anyone help enlighten me or send a link or two as to where I might purchase one?

Thanks

Tony

 

[pdcelec]

changeover switch?