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3. Remove the 4-pin female plug from the PSIO-1 COMM1
plug and connect the red wire to terminal 1 of the plug,
the white wire to terminal 2, and the black wire to ter-
minal 3.
4. Insert the plug back into the COMM1 plug.
IMPORTANT: A shorted CCN bus cable will prevent
some routines from running and may prevent the unit
from starting. If abnormal conditions occur, unplug the
connector. If conditions return to normal, check the CCN
connector and cable. Run new cable if necessary. A
short in one section of the bus can cause problems with
all system elements on the bus.
PROCESSOR MODULE (PSIO-1)
Inputs — Each input channel has 3 terminals; only 2 of the
terminals are used. Application of machine determines which
terminals are used. Always refer to the individual unit wir-
ing for terminal numbers.
Outputs — Output is 20 vdc or 4 to 20 mA. There are 3 ter-
minals, only 2 of which are used, depending on the appli-
cation. Refer to unit the wiring diagram.
NOTE: The 12/6 Input/Output module (PSIO-2) has iden-
tical input and output configurations as the PSIO-1. There is
NO operating software in the PSIO-2 module.
HIGH VOLTAGE RELAY MODULE (DSIO-HV)
Inputs — Inputs on strip J3 are discrete inputs (ON/OFF).
When 24-vac power is applied across the 2 terminals in a
channel it reads the input as an On signal. Zero volts input
is read as an Off signal.
Outputs — Terminal strips J4 and J5 are internal relays whose
coils are signaled to be turned on and off by the micro-
processor (PSIO-1). The relays switch the circuit to which
they are connected. No power is supplied to these connec-
tions by DSIO-HV module.
Replacing Defective Processor Module —
PSIO-1 module replacement part number is 30GX500110.
The unit model and serial numbers are printed on the unit
nameplate located on an exterior corner post (30GX) or the
corner of the control box (30HX). The proper software and
unit configuration data is factory installed by Carrier in the
replacement module. Therefore, when ordering a replace-
ment processor module (PSIO-1), specify the replacement
part number, full unit model number, and serial number. If
these numbers are not provided, the replacement module will
be downloaded with the base software. The base software
settings must be reconfigured by the installer in the field.
Verify the existing PSIO-1 module is defective by using
the procedure described in the Control Modules section.
Refer to Start-up Checklist for 30GX,HX Liquid Chillers
(completed at time of original start-up) found in the job folder.
This information is needed later in this procedure. If the
checklist does not exist, fill out the current factory and
service configuration codes (
list. Tailor the various options and configurations as needed
for this particular installation.
Electrical shock can cause personal injury. Disconnect
all electrical power before servicing.
1. Check that all power to unit is off. Carefully disconnect
all wires from defective module by unplugging the 6 con-
nectors. It is not necessary to remove any of the indi-
vidual wires from the connectors. Remove the screws
securing the green ground wire and communication drain
wire. Save the screws.
The
) sections on a new check-
2. Remove the defective PSIO-1 module by removing its
mounting screws with a Phillips screwdriver, and re-
moving the module from the control box. Save the screws
for later use.
3. Use a small screwdriver to set the address switches S1
and S2 on the new PSIO module to exactly match the
settings on the defective module.
4. Package the defective module in the carton of the new
module for return to Carrier.
5. Mount the new module in the unit control box using a
Phillips screwdriver and the screws saved in Step 2.
6. Reinstall all 6 wire connectors, the green ground wire,
and the communications drain wire.
7. Carefully check all wiring connections before restoring
power.
8. Verify the LOCAL/OFF/REMOTE switch is in the
OFF position.
9. Restore control power. Verify the red and green lights
on top of the PSIO-1 and on front of each DSIO module
respond as described in Control Modules section. The
keypad and display module should also begin its rotat-
ing display.
Using the keypad and display module, press
verify that the software version number matches the
ER (engineering requirement) number shown on the
PSIO-1 label.
10. Press
, scroll down one level at a time, and check
the 3 factory and 2 service configuration codes as re-
corded on checklist. These codes must exactly match the
codes stored in the previous PSIO-1 module for proper
unit operation. These should already be downloaded if
the proper information was supplied when ordering the
replacement module. If the codes do not match, the codes
must be entered by the procedure described in the fac-
tory service code section of Table 22.
11. Once all codes have been verified, and all configura-
tions, set points, and schedules re-entered, return the
LOCAL/OFF/REMOTE switch to its previous position.
Winter Shutdown Preparation —
cooling season the fluid should be drained from the system.
However, due to the cooler circuiting, some fluid will re-
main in the cooler after draining. To prevent freeze-up dam-
age to the cooler tubes perform the following procedure.
1. If accessory cooler heaters have been installed, deener-
gize the heaters to prevent damage and possible safety
hazards when draining, or when there is no liquid in the
system. Remove Fuse 1 to deenergize the heaters. Drain
the fluid from the system.
2. Isolate the cooler from the rest of the system with water
shut off valves.
3. Fill the cooler with an appropriate amount of unhibited
ethylene glycol solution (or other suitable corrosion-
inhibitive antifreeze) for 15° F (8.3° C) below the ex-
pected low ambient conditions.
4. Leave the cooler filled with the antifreeze solution for the
winter, or drain if desired. Be sure to deenergize heaters
(if installed) as explained in Step 1 to prevent damage.
Use an approved method of disposal when removing the
antifreeze solution.
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Troubleshooting
