Trane CGCE207 Chillers

Having some problems with the above model.
1. Unit trips on h/p when first run, seems to settle after several re-starts.
2. Unit trips out on 'antifreeze', does anyone know the antifreeze seting and if/how these can be adjusted?

We have 2 units duty/standby running approx at 2degC flow and about 6degC return, 15% glycol.

Also anyone know wher i can get a service manual for the above?