I'm doing reseach on building a power board for a friends project. He wants to use a 30 amp relay to run four 1000 watt ballasts at 240 volts. Now my question is can we wire two standard 120volt duplex outlets to run at 240 volt so he doesn't have to buy the ridiculously overpriced 240 volt power cord as the cord supplied with the ballasts are rated for 300 volts. Thank for your time

Don't use 120 volt outlets, code violation, And really dangerous, Just make up connections in electrical box and cover and you don't need the recepticles.

I'm doing reseach on building a power board for a friends project. He wants to use a 30 amp relay to run four 1000 watt ballasts at 240 volts. Now my question is can we wire two standard 120volt duplex outlets to run at 240 volt so he doesn't have to buy the ridiculously overpriced 240 volt power cord as the cord supplied with the ballasts are rated for 300 volts. Thank for your timeEverything is typically rated for 250-300V, if not 600V. That is a max rating.

So you want to rig up something dangerous and extremely code-illegal just to avoid buying a cord?
I am actually confused as to what you need. If the ballasts have cords why do you need new ones?

The cords supplied with his ballasts r standard 120 cords (ie: two vertical blades, one small one big, and ground plug) and they ones they want him to buy have two horizontal blades with ground plug and they want 20 bucks a piece. He thinks he can use standard 120 receptacles with the cords that came with his ballasts, I think he should get the 220 cords and receptacles to be safe. Im not trying to "rig" something dangerous or code illegal, I'm trying to prove to him that it shouldn't be done his way and why.
@Stratmando, do u mean hardwire the ballast plugs?

If they came with 120v plugs then I assume they are multi-tap fixtures that came pre-wired for 120v.

You do not need to replace the cords. Just replace the plugs with 240v plugs. You can probably get them for around $10 each.

I was speaking Hardwired.