68
PROCESSOR MODULE (PSIO-1)
Inputs — Each input channel has 3 terminals; only 2 of the ter-
minals are used. Application of machine determines which ter-
minals are used. Always refer to the individual unit wiring for
terminal numbers.
Outputs — Output is 20 vdc or 4 to 20 mA. There are 3 termi-
nals, only 2 of which are used, depending on the application.
Refer to unit the wiring diagram.
NOTE: The 12/6 Input/Output module (PSIO-2) has identical
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 chan-
nel 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 microproces-
sor (PSIO-1). The relays switch the circuit to which they are
connected. No power is supplied to these connections by
DSIO-HV module.
Replacing Defective Processor Module —
The
PSIO-1 module replacement part numbers are shown in
Table 47. 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 replace-
ment module. Therefore, when ordering a replacement proces-
sor module (PSIO-1), specify the replacement part number, full
unit model number, and serial number. The replacement mod-
ules are downloaded with default configuration values that
must be verified for proper operation. Using Table 25, enter
from the HSIO and correct any of the configuration
codes that do not match those in Table 25 for the corresponding
chiller size. 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 check-
list does not exist, fill out the current factory and service con-
figuration codes (
) sections on a new check-list. Tailor
the various options and configurations as needed for this partic-
ular installation.
1. Check that all power to unit is off. Carefully disconnect all
wires from defective module by unplugging the 6 connec-
tors. It is not necessary to remove any of the individual
wires from the connectors. Remove the screws securing
the green ground wire and communication drain wire.
Save the screws.
2. Remove the defective PSIO-1 module by removing its
mounting screws with a Phillips screwdriver, and remov-
ing 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 rotating
display.
Using the keypad and display module, press
to
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 recorded
on checklist. These codes must exactly match the codes
stored in the previous PSIO-1 module for proper unit oper-
ation. 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 factory service
code section of Table 25.
11. Once all codes have been verified, and all configurations,
set points, and schedules re-entered, return the LOCAL/
OFF/REMOTE switch to its previous position.
Winter Shutdown Preparation —
At the end of
each cooling season the fluid should be drained from the sys-
tem. However, due to the cooler circuiting, some fluid will
remain 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, deenergize
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 inhibited ethyl-
ene glycol solution (or other suitable corrosion-inhibitive
antifreeze) for 15
°
F (8.3
°
C) below the expected low ambi-
ent 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.
Table 47 — Replacement Processor
Module Part Numbers
Electrical shock can cause personal injury. Disconnect all
electrical power before servicing.
UNIT
REPLACEMENT MODULE
30GX080-150,160
30GX502892
30GX151,161,175
30GX502891
30GX176
30GX502890
30GX205-265
30GX502842
30GX281-350
30GX503172
30HX076-186
30HX501216
30HX206-271
30HX501215