climavenata chiller help needed

Hello, first time posting........have a climavenata R134A screw chiller here in the USA. I have little information. I do have a manual for the machine but am finding it difficult to navigate.

Problem: Climavenata M#FOCS-CA/SL2712 S#00903970 chiller does not seem to want to bring on the 2nd compressor. there are no faults present. Compressor 1 starts and has about a 4 degree delta T......25 minutes will elapse and it wont bring on compressor 2.
this is an ethanol plant and a backup chiller as well, so the engineers wont let you run it over 30 minutes and then they shut it down and go back to their main chiller.

temps are in C...... had 25C EWT, and 21LWT........ 6C setpoint. this chiller has the W3000 controller. this is first time seeing this thing. I would love to have an operating sequence.

any help is greatly appreciated

I don't know Climaventa's control protocols, but based on other chillers I'm familiar with it looks to me like it's in limiting mode. The water temp's are too high to bring on the second stage without risk of damage. Trane, for e.g, capacity limit if the water temp. is above 15*C.

Try lowering the proportional band in assistance / regulation.