Carrier 48HC 04-28 - Page 48

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T412
Thermostat W2 Input Activated
without W1 Activated
Run unit as if W2 and W1 are
On
Automatic Bad Thermostat or Thermostat Wiring
T413
Thermostat Y and W Inputs
Activated Simultaneously
Run unit in mode activated
first
Automatic Bad Thermostat or Thermostat Wiring
T414
Economizer Damper Actuator Out of
Calibration
Alert Generated Automatic
Calibrate economizer (E.CAL). If problem still exist then
determine what is limiting economizer rotation.
Economizer Damper Actuator
Torque Above Load Limit
Alert Generated Automatic Actuator load too high. Check damper load.
Economizer Damper Actuator
Hunting Excessively
Alert Generated Automatic Damper position changing too quickly.
Economizer Damper Stuck or
Jammed
Alert Generated Automatic
No economizer motion. Check damper blades, gears,
and actuator.
Economizer Damper Actuator
Mechanical Failure
Alert Generated Automatic Check actuator and replace if necessary.
Economizer Damper Actuator
Direction Switch Wrong
Alert Generated Automatic Actuator direction control switch (CCW, CW) wrong.
Excess Outdoor Air Alert Generated Automatic
Economizer Economizing When It
Should Not
Alert Generated Automatic
Economizer not Economizing When
it Should
Alert Generated Automatic
Damper Not Modulating Alert Generated Automatic
T415 IAQ Input Out of Range No IAQ Operations Automatic
Bad sensor, bad wiring, or sensor configured
incorrectly.
T416 OAQ Input Out of Range No OAQ Operations Automatic
Bad sensor, bad wiring, or sensor configured
incorrectly.
T418
OAU Motor Failure Alert generated Automatic Check OAU motors for failure
OAU Dirty Filter Alert generated Automatic Check/change OAU filters
OAU Low CFM Alert generated Automatic Check OAU air flow
OAU General Alarm Alert generated Automatic Check OAU
A420 Supply VFD Fault Unit shutdown Automatic VFD fault occurred, review VFD faults.
LEGEND
ECB — Economizer Control Board
IGC — Integrated Gas Controller
IAQ — Indoor Air Quality
MBB — Main Base Board
OAQ — Outdoor Air Quality
OAT — Outdoor-Air Thermistor
OAU — Outdoor Air Unit
VFD — Variable Frequency Drive
Table 14 — ComfortLink Alarm Codes (cont)
ALARM
OR
ALERT
NUMBER
DESCRIPTION
ACTION TAKEN BY
CONTROL
RESET
METHOD
PROBABLE CAUSE