Ingersoll-Rand Xe-145M, Pocket Manual

Page: 47 / 116

46
loads it will create a higher differential pressure at
1AVPT sensor causing the alarm High Inlet Vacuum).
2APT
– Inter stage Air Pressure (Two-stage
Only)
Mounted between the first and second stage of the
compressor Air End, 2APT ensures the male rotor of
the second stage Air End is rotating when the machine
is running loaded/unloaded. The trip occurs when the
pressure exceeds 75 psi (5.17 Bar).
2APT has an output signal range of 0 psi (0 Bar) at 0.5
VDC to 225 psi (15.51 Bar) at 4.5 VDC.
3APT - Sump Pressure
Sump pressure is monitored for several reasons,
including a comparison to package discharge pressure
to calculate separator element differential. 3APT also
provides logic for the controller to position the inlet
valve during unloaded operation.
The normal unloaded sump pressure is maintained
within a range of 18-24 PSIG (1.24-1.65 Bar) to ensure
adequate coolant flow and allow the unloaded
compressor to operate at a low horsepower condition.