You can get computer power cords with
NEMA 6 plugs, which is the norm for 240v appliances. They're not common in residences in north america, but not that uncommon commercially.
You need to ask the electrician what kind of receptacle he is installing because there are different heads for 20AMP and 30AMP. You can buy power bars (PDUs) that have different heads too. I am not suggesting you buy this one but it will give you an idea, Now look at one with 20AMP and you will see the plug is different.
http://www.overstock.com/Electronics/Tripp-Lite-PDUMNV30HV-PDU-Monitored-208V-240V-30A-24-Outlet/4313583/product.htmlThe plug is called NEMA L6-30P. But that is for 30 AMP