I built a garage and electrician installed what a plug that won't receive my 250 volt appliances. The hardware store tells me it is a dryer plug and can't understand why it was installed in a garage. It is a NEMA 30 AMP (14-30R) 125/250 volt receptacle, with 4 holes. So, I have 4 wires (red, black, white and bare ground) and need to set it up with the 3 prong plug they provided me. It is a 30 AMP 250 Volt receptacle with 3 prongs holes. One of which is labeled ground.
How do I set this up - if I can? Do both the 2 live wired go in one connection?