We just bought a house that we are fixing up. We are switching from 100 amp service to 200 amp service. So in the mean time we only have 30 amps (we had to get a new meter).

Either way, when we moved in there was a working fridge, we unplugged it and cleaned it out. However, it's been plugged in for 2 days and is not getting cold. Could this be because it's only running off the 30 amp service? Or would it definitely be a problem with the fridge?

What else is on the 30 AMP supply? Could be a voltage drop issue. 30 AMPS is more than enough for the frige. I hope someone wired the temporary circuit properly, you could have connected to a 240 VAC circuit.

Are your coils clean? When you unplugged it and had to re-start it it takes a lot to move that much heat back out of the unit. Check the receptacle with a volt meter when it's running and make sure you have 120 volts under load. If not, you have a problem.