Are splices or wirenuts allowed in a disconnect on the line side feed? An HVAC contractor installed a new 5 ton condensing unit outside and they replaced the disconnect also. The feed wires were short so instead of cutting off the conduit nipple about 6 inches or just replacing the wire to the panel which was just inside the wall approximately 9 feet away. They used pigtails and blue wirenuts the pigtails overheated melted the insulation and the plastic around the lugs so the condensing unit was now trying to run on 92 volts instead of 240. Is this a proper installation by the NEC ?

I have to retract my statement, Feed on the line side, I can't say, some good people here will answer shortly, I hope.
I never did it, never thought about it. Better off having the additional load on a separate breaker.
Wirenuts and splices are allowed.

Spanky,
Can you elaborate on your question?
Yes, the code allows splices in a disconnect, panel... etc. although
Making a connection to the line or load side depends on what you're connecting,
The size of the overcurrent protection supplying the disconnect, the wire size...
Please tell us more...

Here is the actual text from the 2008 edition of the NEC, as you can see it is not a simple yes or no answer: