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TROUBLESHOOTING
The 30GX,HX screw chiller control has many features to
aid in troubleshooting. By using the keypad and display mod-
ule and the Status function, operating conditions of the chiller
are displayed while the unit is running. The Test function
allows for operational checkout of compressor loaders, fans,
EXVs, solenoids, and other components while the chiller is
stopped. The Service function displays how configurable items
are configured and provides a manual control mode where the
compressors can be started and loaded. If an operating fault is
detected, an alarm is generated and an alarm code is displayed
under the subfunction
along with an explanation of
the fault. Up to 10 current alarm codes are stored under this
subfunction. For checking specific items, see Table 14.
Checking Display Codes —
To determine how the
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 LOCAL/
OFF/REMOTE switch to OFF position. All compressors and
solenoids stop immediately.
Complete Unit Stoppage —
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)
• LOCAL/OFF/REMOTE switch moved to OFF position
• freeze protection trip
• low flow protection trip
• open contacts in chilled water flow switch (optional)
• 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 processor module and
other control modules
• low refrigerant pressure
• off-to-on delay is in effect
Single Circuit Stoppage —
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 CPM module
Stoppage of one circuit by a safety device action does not
affect other circuit. When a safety device trips, the circuit is
shut down immediately and EXV closes.
Restart Procedure —
After the cause for stoppage has
been corrected, restart is either automatic or manual, depending
on the fault. Manual reset requires that the alarm(s) be reset via
the HSIO. Press
and then
to clear manual
reset alarms. If the Alarm Reset Select feature is selected
(
), a manual reset alarm can also be reset by switching
the LOR switch from LOCAL/REMOTE to OFF and back to
LOCAL/REMOTE again. If an alarm was from the CPM mod-
ule, depress the reset button located on the control/fuse panel
for 5 seconds before clearing the alarm through the HSIO.
Some typical fault conditions are described in Table 35. For a
complete list of fault conditions, codes, and reset type, see
Table 36.
POWER FAILURE EXTERNAL TO THE UNIT — Unit
restarts automatically when power is restored.
Table 35 — Typical Stoppage Faults
and Reset Types
Alarms and Alerts —
These are warnings of abnormal
or fault conditions, and may cause either one circuit (alert) or
the whole unit (alarm) to shut down. They are assigned code
numbers as described in Table 36. The alarm descriptions are
displayed on the HSIO when the
subfunction is en-
tered. When a communication loss occurs to a hardware point,
an alert or alarm may be generated. Refer to Table 37. The
PSIO also recognizes illegal configurations. Illegal configura-
tions are shown in Table 38.
When an alarm or alert is activated, the relay K3 (for 30GX
units) or K6 (for 30HX units) will close. See Field Wiring sec-
tion on page 70 for wiring details.
Table 36 contains a detailed description of each alarm and
alert code error and possible cause.
ALARM/ALERT RESET — Automatic alarms will reset
without operator intervention if the condition corrects itself.
One or more of the following methods must be used to reset
manual alarms:
To reset PSIO alarms, first find and correct the cause of the
alarm. Then from the HSIO press
and
to
clear the alarm. If the Alarm Reset Select in
is set to
“1,” the default value, the LOCAL-OFF-REMOTE switch can
be switched from “Local” or “REMOTE” to “OFF” for 5 sec-
onds and back to its original position to reset the alarm.
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.
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.
STOPPAGE FAULT
RESET TYPE
Loss of Condenser Flow (30HXC)
Manual reset
Cooler Freeze Protection (Chilled
Fluid, Low Temperature)
Auto reset first time, manual if repeated
in same day
Cooler Fluid Pump Interlock
Automatic reset (Manual for closed
contacts when pump is off)
Control Circuit Fuse Blown
Unit restarts automatically when power
is restored
High-Pressure Switch Open
Manual reset
Low Sat. Suction Temperature
Manual reset
Low Oil Pressure
Manual reset
Loss of Communications with
WSM or FSM Controller
Automatic reset
LEGEND
FSM
— Flotronic™ System Manager
WSM — Water System Manager
ENTER
ENTER
