Unit cooling fan comes on power to compressor 246.6 volts but the compressor is not working. Is my compressor toast or what. The compressor is hot to touch and the lines are not cool. Been having trouble with the relay contacts arching and losing contact but not now just not cooling.

Let the compressor completely cool. Then take your meter and give the compressor a OHM test and also a test to ground. This will tell you an aprox condition of the compressor. If that all checks well and it is a single phase compressor (Usually residential) then you can also test the run capacitor as well as the start capacitor if used. You should also test the start relay for the start capacitor as well as the main contactor for the conditions of the contacts.

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That contactor is a $15 part that may have cost you a compressor. Contactors should be replaced at the first sign of trouble, if not before! Replace yours at least every 5 years; sooner if it looks burnt.
Of course, if you are using a service company, it might cost you $200 to have that $15 part replaced.

Before giving up on the compressor, try a start-assist capacitor. If you already have one, try a new one. A common type is called an SPP6; they are cheap and EASY to install. This will help the compressor get started. When a compressor won't start, it gets hot and an internal overload opens up, disconnecting power.