Service manual

25 – 2
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 1.9
enable Superheat Monitoring on the screen.
• As previously described, Cool Compression
compressor does not have an oil pump. Instead
it has a suction oil injection solenoid to pro-
vide oil and liquid ammonia for lubrication and
cooling.
• Cool Compression liquid injection 1 and liq-
uid injection 2 outputs will operate as high / low
pressure ratio solenoid outputs.
Control Functions
In the Compressor Control Menu, special cool compres-
sion control functions are now available, see Figure 25-2.
Compressor Control Screen - Cool Compression Control
(Page 4). These new functions are:
• Auto Load
• Suction Oil Injection Settings
• Danfoss Positioning Valve Settings
Auto Load
• Auto load operation will force the compressor to
load to a minimum value once the compressor has
started. By loading the compressor to a minimum
value, and maintaining this capacity, a pressure ratio
is created across the compressor, to ensure adequate
lubrication of the compressor, and also that the com-
pressor does not experience high discharge super-
heat conditions. Since compressor lubrication is of
great importance, all load limiting is disabled when
auto load is engaged.
• Auto Load at Start
• Defi nes the value at which Compressor (ca-
pacity slide) should be loaded (and maintained)
at start if Auto Load is enabled.
• Auto Load Timer
• This timer defi nes the maximum time that
the Auto Load operation will be engaged. After
the timer expires, Auto Load will be disengaged.
Section 25 • Cool Compression Control
Figure 25-2. Compressor Control Screen - Cool Compression Control (Page 4)