Suction temperature readings of −40.0 or 245.0 indicate
an open or shorted circuit (respectively). Verify that the wir-
ing connections to PSIO2 have been made correctly. If the
readings above are satisfactory, then proceed with the fol-
lowing system pressure check:
HSIO ENTRY
KEYPAD
DISPLAY
READING NAME
(EXPECTED DISPLAY)
PRESSURE System pressures
DPA X
Discharge pressure, circuit A
(0.0 psig)
SPA X
Suction pressure, circuit A
(0.0 psig)
DPB X
Discharge pressure, circuit B
(0.0 psig)
SPB X
Suction pressure, circuit B
(0.0 psig)
Pressure readings other than 0.0 psig at this point indicate
that the calibration for that transducer was unsuccessful. Re-
peat the calibration procedure above for any transducer value
that is
6
1.0 psig. After the Transducer Installation section
below is completed, this system pressure check will be
repeated.
Transducer Installation
DISCHARGE PRESSURE TRANSDUCER (ALL UNITS
— SEE FIG. 10-12)
1. Remove the discharge valve stem cap and fully backseat
the valve.
2. Remove the flare cap from the fitting threaded into the
discharge valve body.
3. Unplug the harness from the proper transducer.
4. Thread the transducer onto the flare fitting and tighten.
See Fig. 13-16.
5. Reconnect the transducer harness plug.
6. Turn the valve stem 1 to 1
1
⁄
2
full turns clockwise.
7. Replace valve stem cap.
8. Repeat Steps 1-7 for the other compressor.
SUCTION PRESSURE TRANSDUCER (ALL UNITS)
1. Locate and remove the low-pressure switch on the com-
pressor (See Fig. 10-12).
2. Unplug the harness from the proper transducer.
3. Thread the transducer onto the flare fitting and tighten.
See Fig. 13-16.
4. Reconnect the transducer harness plug.
5. Open the compressor electrical junction box, and follow
the low-pressure switch leads to the box.
6. Cut the 2 low-pressure-switch leads just outside of the
box, and pull the leads through the connector and into the
box.
7. Strip each lead back
1
⁄
2
-in., twist leads together, and con-
nect them with a wire nut (provided).
8. Replace the cover on the compressor electrical junction
box. The low-pressure switch will no longer be used.
9. Repeat Steps 1-8 for the other compressor.
DISCHARGE VALVE
STEM CAP
LOW-PRESSURE
SWITCH
Fig. 10 — Low-Pressure Switch and Discharge Valve Stem Cap Locations (024-034 Units)
10