[jmastillo]

The unit trips the breaker. It doesn't do it all the time, but more then not. The specs on the back of the unit state min/max 45/60 amp. The old unit only used a 30 amp. Can I replace the 30 amp with a 45/50 amp without burning down the house or causing other electircal issues?

[stanfortyman]

So are you saying the old unit was replaced but the wiring was not??

If the new unit calls for a 45A breaker minimum what wold posses the installer to keep the 30??

You need to tell us the "Minimum circuit ampacity" and the "Maximum fuse or breaker size".

Not "min/max, 45/60". Be specific.

If the minimum circuit ampacity really is 45 amps then a strong NO, you cannot simply increase the breaker size. You MUST run a new circuit.
While you're at it find another A/C guy.

[Stratmando]

A pair of #6's, and 10 for ground would work on 50 or 60 Amp Breaker.
If it was 30 Amps, wiring may need upgrading. Don't put On a Breaker larger than the wire can handle.
If existing wiring was #6, you Lucked out.