Arrive International Terminal 3 transfer Domestic Terminal 3

I will be arriving Beijing international terminal T3E from Sydney at 4.40am in the morning and have to go to T3C for domestic connection to Harbin, I have 2hr.50min transfer time I believe there is a shuttle train that takes you from T3E to T3C is that correct and does it run 24 hours every 3 or 4 minutes. I should have enough time for the immigration and security checks in both E and C Zones in that time is this correct.
regards Paul