1-14
1.5.5.5
Saturator Refrigerant Solenoid Valve
Reference Drawings 95S39908, 95S39917
The Saturator Refrigerant Solenoid Valve SOL5, when activated, allows refrigerant to be
injected into the refrigeration evaporator EX1 to cool and control the temperature of the
saturator. Activation of this solenoid valve is accomplished by applying a low from the CPU
(monitored at TIB terminal C0) to the optical input (-) side of SSR0 on the Solid State Relay
Board. Saturation temperature is controlled through fixed frequency pulse width modulation
of SOL5. Valve actuation voltage is 24 VDC.
1.5.5.6
Saturator Inlet/Outlet Heater
Reference Drawing 95S39908
The Saturator Inlet/Outlet Heater H2 is a resistive heating element which keeps the inlet and
outlet tubing of the saturator slightly warmer than the saturator itself in order to limit
condensation in this area. Activation of this heater is accomplished by applying a low from
the CPU (monitored at TIB terminal C5) to the optical input (-) side of SSR5 on the Solid
State Relay Board. Heater drive voltage is 24 VDC.
1.5.5.7
Saturator Fluid Heater
Reference Drawings 95S39909, 95S39917
The Saturator Fluid Heater H1 is a resistive heating element, activated by a two-stage control
process. Heat limit switch HLS1 must be in the normally closed position, indicating that
saturator fluid temperature is within allowable limits (i.e. below 30 °C). Activation is then
accomplished by applying a low from TIB channel B5 to the optical input (-) side of SSR10.
Saturator heater temperature is controlled through fixed frequency pulse width modulation of
the heater power at the AC line voltage.
1.5.5.8
Saturator Fluid Circulation Pump
Reference Drawings 95S39908, 95S39917
The Saturator Fluid Circulation Pump FP1 is a centrifugal pump energized by applying a low
from the CPU (monitored at TIB terminal C6) to the optical input (-) side of SSR6 on the
Solid State Relay Board. The pump is powered at AC line voltage.
1.5.5.9
Saturator Refrigeration Compressors
Reference Drawings 95S39909, 95S39917
The R-134A Compressor, C1, is energized by applying a low from the CPU (monitored at
TIB terminal C6) to the optical input (-) side of SSR8. The R-23 Compressor, C2, is
energized by applying a low from the CPU (monitored at TIB terminal B6) to the optical
input (-) side of SSR9. Compressor C2 is not activated by the computer until compressor C1
has been on for several minutes. Both compressors are powered at AC line voltage.
