Specifications

38
Strainer — Periodic cleaning of the required field-installed
strainer is required. Pressure drop across strainer in excess of
3 psi (21 kPa) indicates the need for cleaning. Normal (clean)
pressure drop is approximately 1 psi (6.9 kPa). Open the
blowdown valve to clean the strainer. If required, shut the chill-
er down and remove the strainer screen to clean. When strainer
has been cleaned, enter ‘YES’ for Strainer Maintenance Done
(Run Status
 PM  S.T.MN).
Replacing Defective Modules — The Comfort-
Link replacement modules are shown in Table 30. If the main
base board (MBB) has been replaced, verify that all configura-
tion data is correct. Follow the Configuration mode table and
verify that all items under sub-modes UNIT, OPT1 and OPT2
are correct. Any additional field-installed accessories or op-
tions (RSET, SLCT sub-modes) should also be verified as well
as any specific time and maintenance schedules.
Refer to the Start-Up Checklist for 30MP 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 information in the Config-
uration mode on a new checklist. Tailor the various options and
configurations as needed for this particular installation.
1. Check that all power to unit is off. Carefully disconnect
all wires from the defective module by unplugging its
connectors.
2. Remove the defective module by removing its mounting
screws with a Phillips screwdriver, and removing the
module from the control box. Save the screws later use.
3. Verify that the instance jumper (MBB) or address switch-
es (all other modules) exactly match the settings of the
defective module.
NOTE: Handle boards by mounting standoffs only to
avoid electrostatic discharge.
4. Package the defective module in the carton of the new
module for return to Carrier.
5. Mount the new module in the unit’s control box using a
Phillips screwdriver and the screws saved in Step 2.
6. Reinstall all module connectors. For accessory Naviga-
tor™ device replacement, make sure the plug is installed
at TB3 in the LEN connector.
7. Carefully check all wiring connections before restoring
power.
8. Verify the ENABLE/OFF/REMOTE CONTACT switch
is in the OFF position.
9. Restore control power. Verify that all module red LEDs
blink in unison. Verify that all green LEDs are blinking
and that the scrolling marquee or Navigator™ display is
communicating correctly.
10. Verify all configuration information, settings, set points
and schedules. Return the ENABLE/OFF/REMOTE
CONTACT switch to its previous position.
Table 30 — Replacement Modules
MAINTENANCE
Recommended Maintenance Schedule —
The
following are only recommended guidelines. Jobsite condi-
tions may dictate that maintenance schedule is performed
more often than recommended.
Routine
:
Every month:
• Check moisture indicating sight glass for possible refrig-
erant loss and presence of moisture.
Every 3 months (for all machines):
• Check refrigerant charge.
• Check all refrigerant joints and valves for refrigerant
leaks, repair as necessary.
• Check chilled water flow switch operation.
• Check compressor oil level.
Every 12 months (for all machines):
• Check all electrical connections, tighten as necessary.
• Inspect all contactors and relays, replace as necessary.
• Check accuracy of thermistors, replace if greater than
± 2° F (1.2° C) variance from calibrated thermometer.
• Check to be sure that the proper concentration of anti-
freeze is present in the chilled water loop, if applicable.
• Verify that the chilled water loop is properly treated.
• Check refrigerant filter driers for excessive pressure
drop, replace as necessary.
• Check chilled water and condenser strainers, clean as
necessary.
• Perform Service Test to confirm operation of all
components.
• Check for excessive cooler approach (Leaving Chilled
Water Temperature — Saturated Suction Temperature)
which may indicate fouling. Clean evaporator if
necessary.
WARNING
Electrical shock can cause personal injury and death. Shut
off all power to this equipment during installation. There
may be more than one disconnect switch. Tag all discon-
nect locations to alert others not to restore power until work
is completed.
MODULE
REPLACEMENT
PART NO.
(with Software)
Main Base Board (MBB) 30MP500346
Scrolling Marquee Display HK50AA031
Energy Management Module (EMM) 30GT515218
Navigator Display HK50AA033