Cornelius Diplomat, how long for an ice bank to form

[lurker18]

I am just getting this running, and before I try to find someone to recharge the system, even if I can find someone, how long will it take for an ice bank to start up.  I am nowhere near understanding how this thing works, and finding information on this unit is getting to be very difficult.  I had it running, I could hear the compressor start, and it ran for close to 30 minutes, but there was no ice forming, and I don't think the water was getting much cooler.  I didn't have it topped all the way up with water, and I'm going to try that tomorrow, but how long should I wait?