York pc compressor unloading problem

Hi,
Can anyone think for expert solution on the following problem, kindly suggest if you have any idea in this.

Ambient Air cooled Liquid chiller
York model - YAEP99WD9C50PA
controller - YAEP
Compressor - York PC, 8cylinder, 2 unloader valves

Problem is with compressor loading
Compressor is running at 45% load continuously, not going in load.
Running parameters are
SP-75, DP-285, Oil pr-60, current-45%, temp setting 52-56, LWT - 68
checked- solenoid valves electric supply, not present (i assume there shouldn’t be for loading)
What could be the reason for continuous unload? i suspect any stuck up of unloader valves in side compressor but how is it possible for both at a time or any other reason could be?
Kindly suggest,
Thanks in advance
Regards
T.V.Rao

Hi TV RAO.
Sorry as your settings are in imperial and you don't say what refrigerant you are using?
I not going to try and analyse your running parameters.
But I will ask what does the display called "Temperature demand" on the Micro controller say?
Only there are several Controller settings that can and do influence the "Load Rate and how the Compressor loads up and down.
When reading those displayed settings press the status button and read what is displayed.
What is displayed may help?
Grizzly

Is problem is solved ?