Sullair ShopTek ST400 User Manual page 18

USER MANUAL
S T
™
HOP EK
1. Air Outlet
2. Unload Solenoid Valve
3. Air Inlet
4. Minimum Pressure/Check Valve
service line pressure will rise. The Controller de-
energizes the solenoid valve when the pressure
exceeds 127 psig (8.8 bar) allowing the separator
tube air pressure to be supplied directly which closes
the inlet valve. At the same time the solenoid valve
exhausts the system pressure to the atmosphere and
lowers the separator tube pressure to approximately
29 psig (2.0 bar). A check valve in the air service line
prevents air from back-flowing to the separator tube.
16
Figure 2-6: Control System, ST1100, ST1500, 15-20 HP
5. Separator Tube
6. Pressure Transducer
7. Controller
02250180-090 R00
When the pressure drops to the low setting: (cut-in
pressure) usually 112 psig (7.7 bar) for high pressure
(9 bar) compressors, 137 psig (9.4 bar) for (10 bar)
compressors, 161 psig (11.1 bar) for (12 bar)
compressors: the Controller energizes the solenoid
valve and prevents line pressure from reaching the
inlet control valve.
SECTION 2