Carrier 48LC Series Controls, Start-Up, Operation And Troubleshooting page 35

cooling or heating mode depending upon which input turned
on first. This alert resets automatically when Y1, Y2, and Y3
are not on simultaneously with W1 and W2.
Alert A191 – TSTAT IMPROPER COOL
This alert occurs in Thermostat mode when Y2 or Y3 is ener-
gized and Y1 is not. Verify thermostat and thermostat wiring.
When this occurs, the control will treat the inputs as a number
instead of specific input. Example a Y2 and Y3 would mean 2
cooling inputs so the control would treat that as is a Y1 and Y2
was active. This alert resets automatically when Y1 is turned
On.
Alert A192 – TSTAT IMPROPER HEAT
This alert occurs in Thermostat mode when W2 is energized
and W1 is not. Verify thermostat and thermostat wiring. When
W2 turns On, the software will behave as if W1 and W2 are
both On. When W2 turns Off, the software will behave as if
W1 and W2 are both Off. This alert resets automatically when
W1 is turned On.
Fault F200 – FIRE SHUTDOWN
This fault occurs when the fire shutdown input is either open or
closed, depending upon its configuration. This fault is usually
caused by an auxiliary device that is trying to shut down the
unit, e.g., smoke detector. This will cause a unit shutdown con-
dition. Verify that the configuration is set correct, verify the
wiring and auxiliary device. This fault resets automatically.
Fault F201 – CONDENSATE OVERFLOW
This fault occurs when the COFS input is either open or closed de-
pending upon its configuration. This fault is usually caused by wa-
ter reaching a high level in the drain pan. This will cause a cooling
lockout. Verify that the configuration is set correct, verify the wir-
ing and auxiliary device. This fault resets automatically.
Alert A203 – DIRTY FILTER
This alert occurs when the Filter Status switch senses a
plugged filter for 5 continuous seconds after the indoor fan has
been running for 10 seconds or if the fan has run for longer
than the change filter time. Because the Dirty Air Filter switch
can be configured normally opened or closed, the switch might
be open or closed. Verify that the configurations are set correct,
verify the wiring and filter status switch. The hose should be
connected to the low side of the switch. The alert resets auto-
matically if it was tripped due to the filter switch. If the alert is
tripped because of the timer, it will need to be reset after the fil-
ter has been replaced or inspected. Rest the time with the RE-
SET FILTER TIME point located under RUN STATUS 
GENERAL or INPUTS  GENERAL INPUTS.
Fault F204 – REMOTE SHUTDOWN
This fault occurs when the remote shutdown input is either
open or closed, depending upon its configuration and config-
ured to set a fault. This fault is usually caused by an auxiliary
emergency device that is trying to shut down the unit. This will
cause a unit shutdown condition. Verify that the configuration
is set correct, verify the wiring and auxiliary device. This fault
resets automatically.
Alert A210 – GENERAL STATUS
This alert occurs when the general status input is either open or
closed, depending upon its configuration and configured to set
a alert. This alert is usually caused by an auxiliary switch de-
vice that is trying to send a warning about the unit. Verify that
the configuration is set correct, verify the wiring and auxiliary
device. This alert resets automatically.
Fault F211 – GENERAL STATUS
This fault occurs when the general status input is either open or
closed, depending upon its configuration and configured to set a
fault. This fault is usually caused by an auxiliary switch device
that is trying to shut down the unit. This will cause a unit shut-
down condition. Verify that the configuration is set correct, verify
the wiring and auxiliary device. This fault resets automatically.
Fault F310 – CIRA DOWN DUE TO FAIL
This fault occurs when both compressors on circuit A have
3 strikes. Investigate the alerts that caused the strikes to occur,
and correct or test as needed. Manual alarm reset or power cy-
cle is required to reset this fault.
Fault F311 – CIRA LOW CHARGE
This alert occurs when the compressors are off and both the
discharge and suction pressure are less than the low charge lev-
el (LOW CHARGE LEVEL) and OAT is greater than the low
charge limit (NO LOW CHARGE OAT). The cause of the alert
is usually low refrigerant pressure or faulty pressure transduc-
ers. This alert only occurs when the compressor is OFF be-
cause the low refrigerant pressure alert will handle this situa-
tion when the compressor is operating. Manual alarm reset or
power cycle is required to reset this fault.
Alert A312 – CIR.A UNEXPECTED OFF
These alerts occur when the suction pressure raises the config-
ured amount and the pressure ratio drop the configured amount
both in a 10 second window during compressor operation.
When this occurs, the control turns off the compressors and
logs a strike for the compressor that was on. This alerts reset
automatically. The possible causes are: high-pressure switch
(HPS) open (the HPS is wired in series with compressor relays
on the MBB), compressor internal protection is open, or a wir-
ing error (a wiring error might not allow the compressor to
start).
Alert A313 – CIR.A HIGH DISCHARGE
This alert occurs when the discharge pressure is greater than
the configured CIR.A SDP LIMIT amount. This alert resets
automatically when the pressure falls 20 psig below the thresh-
old. When running both compressors, the control will remove
A1 and add a strike to it. The control will also set the ODFs to
the high cool speed. The cause of the alert is usually an over-
charged system, high outdoor ambient temperature coupled
with dirty outdoor coil, plugged filter drier, or ODF speeds be-
ing set too low.
Alert A314 – CIR.A HPS TRIP
This alert occurs when the discharge high pressure switch
opens. This alert resets automatically when the pressure falls
below the switch threshold and the switch closes for 3 minutes.
The control will add a strike for which ever compressors were
on. The control will also set the ODFs to the high cool speed.
The cause of the alert is usually an overcharged system, high
outdoor ambient temperature coupled with dirty outdoor coil,
plugged filter drier, or ODF speeds being set too low.
Alert A315 – CIR.A LOW DISCHARGE
This alert occurs when the discharge pressure is less than the
OAT plus the configured LOW DISCHARGE LEV amount.
This alert resets automatically. The control will add a strike for
whichever compressors were on. The cause of the alert is usu-
ally an undercharged system, low outdoor ambient temperature
coupled with dirty outdoor coil, plugged filter drier, or ODF
speeds being set too high.
Alert A316 – CIR.A LOW SUCTION
This alert occurs when the compressor is operating and the
evaporating temperature (converted from the suction pressure)
is less than configured low suction control levels, LOW SUC
LEVEL 1, LOW SUC LEVEL 2, or LOW SUC LEVEL 3. The
circuit SST value must be less than LOW SUC LEVEL 1 (for
5 minutes), LOW SUC LEVEL 2 (for 4 minutes), or LOW
SUC LEVEL 3 (for 3 minutes when using the economizer and
1.5 minutes when not using the economizer) for the alert to oc-
cur. When the outdoor temperature is less than 40°F, the above
values are reduced 1°F for every 2°F OAT is below 40°F. All
the above timers will reset if the suction temperature rises
above LOW SUC OK TEMP for 1 minute. This alert causes a
strike for the respective circuit. This alert will activate when
the coil becomes frosted. However, during the 15 minute reset
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