Troubleshooting; Checking Display Codes; Unit Shutoff; Complete Unit Stoppage - Carrier ComfortLink 6 Series Controls, Start-Up, Operation, Service, And Troubleshooting

TROUBLESHOOTING

The 30GXN,R and 30HX screw chiller control has many
features to aid in troubleshooting. By using the Navigator
control, operating conditions of the chiller can be viewed while
the chiller is running. The Service Test function allows for
testing of all outputs and compressors. Verify that the chiller is
properly configured, including options and/or accessories,
using the Configuration mode. For checking specific items,
refer to the Mode/Sub-Mode directory (Table 11).
Checking Display Codes —
machine has been programmed to operate, check the diagnostic
information displayed in the Status function and the configura-
tion information displayed in the Service function.
Unit Shutoff —
To shut the unit off, move the Enable/
Off/Remote Contact switch to the Off position. Both circuits
will complete a pumpdown cycle and all compressors and sole-
noids will shut off. For extreme cases, move the Emergency
On/Off switch to the Off position. All compressors, solenoids
and other outputs will stop immediately.
Complete Unit Stoppage —
can be caused by any of the following conditions:
• cooling load satisfied
• remote on/off contacts open
• programmed schedule
• emergency stop command from CCN
• general power failure
• blown fuse in control power feed disconnect
• open control circuit fuse(s)
• Enable/Off/Remote Contact switch moved to Off
position
• freeze protection trip
• low flow protection trip
• open contacts in chilled water flow switch
• Open contacts in any auxiliary interlock. Terminals that
are jumpered from factory are in series with control
switch. Opening the circuit between these terminals
places unit in Stop mode, similar to moving the control
switch to Off position. Unit cannot start if these contacts
are open. If they open while unit is running, the unit
stops
• cooler entering or leaving fluid thermistor failure
• low/high transducer supply voltage
• loss of communications between the Main Base Board
(MBB) and either the EXV board, SCB board or either
CCP module
• low refrigerant pressure
• off-to-on delay is in effect
If a stoppage occurs more than once as a result of any of
the above safety devices, determine and correct the
cause before attempting another restart.
Single Circuit Stoppage —
can be caused by the following:
• low oil pressure
• open contacts in high pressure switch
• low refrigerant pressure
• thermistor failure
• transducer failure
• alarm condition from CCP module
Stoppage of one circuit by a safety device action does not
affect other circuit. When a safety device trips, the circuit is
To determine how the

Complete unit stoppage

Single circuit stoppage

shut down immediately and EXV closes. Refer to Table 31 for
typical stoppage faults and reset types.
If a stoppage occurs more than once as a result of any of
the preceding safety devices, determine and correct the
cause before attempting another restart.
Restart Procedure —
been corrected, restart is either automatic or manual, depending
on the fault. Manual reset requires that the alarm(s) be reset via
the Navigator. Select the RCRN item under the Alarms mode.
Press , and
ENTER ENTER
alerts. A password entry may be required. Some typical fault
conditions are described in Table 31. For a complete list of
fault conditions, codes and reset type, see Table 32.
POWER FAILURE EXTERNAL TO THE UNIT — Unit
restarts automatically when power is restored.
Alarms and Alerts —
or fault conditions and may cause either one circuit or the
whole unit to shut down. They are assigned code numbers and
a detailed description of each alarm/alert code error including
possible causes is shown in Table 32. The alarm descriptions
are displayed on the Navigator under the 'CRNT' or 'HIST'
sub-modes of the Alarms mode. The Main Base Board
also recognizes and reports illegal configurations as shown in
Table 32.
When an alarm or alert is activated configurable, the alarm
relay output (MBB relay K7, terminals TB5-11,12) is ener-
gized. The alarms and alerts indicate failures that cause the unit
to shut down, terminate an option (such as reset) or result in the
use of a default value such as a set point. Refer to Table 32 for
more information.
Up to 50 alarms/alerts can be stored at once. Use Alarm and
Alert tables to view and clear alarms. ComfortLink™ Com-
pressor Protection (CCP) module alarms require an additional
step to reset alarms. To clear these alarms, first find and correct
the cause of the alarm. Then press and hold the reset button on
the CCP board for 5 seconds. This action will reset only the
alarmed circuit or compressor, and clear the CCP. Next, reset
the alarm(s) using the Navigator as shown in Table 26. For
configuration header fault alarms from the CCP module, move
the Enable/Off/Remote Contact switch to the Off position.
Wait for all compressors to stop. Turn off the unit control pow-
er. Correct the configuration header problem and restore unit
control power.
Table 31 — Typical Stoppage Faults
and Reset Types
STOPPAGE FAULT
Loss of Condenser Flow (30HXC)
Cooler Freeze Protection (Chilled
Fluid, Low Temperature)
Cooler Pump Interlock
Control Circuit Fuse Blown
High-Pressure Switch Open
Low Sat. Suction Temperature
Low Oil Pressure
Loss of Communications with
WSM or CSM Controller
LEGEND
CSM — Chillervisor™ System Manager
WSM — Water System Manager
41
After the cause for stoppage has
again to reset all current alarms and
These are warnings of abnormal
RESET TYPE
Manual reset
Auto reset first time, manual if
repeated in same day
Manual reset
Unit restarts automatically
when power is restored
Manual reset
Manual reset after 1 hour
Manual reset
Automatic reset