Carrier 48AJ Operating And Service Manual page 92

T221 (Outdoor Air Quality Sensor Failure) — The indoor air
→
quality sensor (Inputs AIR.Q
the 4 to 20 mA sensor is below 2 mA. If the outdoor air quality
sensor fails, OAQ defaults to 400 ppm and demand control
ventilation will continue. Recovery is automatic. Reason for
error is either a faulty sensor, wiring error, or damaged input on
the CEM control board.
T229 (Economizer Minimum Position Override Input Fail-
ure) — If the unit is configured to use the remote position
override for the economizer and the input Econo Min. Pos.
→
Override (Configuration IAQ
20 mA reading is less than 2 mA then an alert will occur and
the default software minimum position will be used for the
economizer. The alert will automatically reset.
T300 (Space Temperature Below Limit) — If the space tem-
perature is below the configurable SPT Low Alert
Limits (occupied [Configuration
5 minutes or unoccupied [Configuration
for 10 minutes), then an alert will be broadcast. The alert will
automatically reset.
T301 (Space Temperature Above Limit) — If the space tem-
perature is above the configurable SPT High Alert
Limits (occupied [Configuration
5 minutes or unoccupied [Configuration
for 10 minutes), then an alert will be broadcast. The alert will
automatically reset.
T302 (Supply Temperature Below Limit) — If the supply-air
temperature measured by the supply temperature sensor is
below the configurable SAT LO Alert Limit/Occ (Configura-
→ →
tion ALLM SA.L.O) for 5 minutes or the Low Supply air
temperature alert limit unoccupied mode (Configuration-
→ →
ALLM SA.L.U) for 10 minutes, then an alert will be
broadcast.
T303 (Supply Temperature Above Limit) — If the supply
temperature is above the configurable SAT HI Alert Limit Occ
→ →
(Configuration ALLM SAH.O) for 5 minutes or the SAT
HI Alert Limit/Unocc (Configuration
10 minutes, then an alert will be broadcast. The alert will
automatically reset.
T304 (Return Air Temperature Below Limit) — If the return-
air temperature measured by the RAT sensor is below the
configurable RAT LO Alert Limit/Occ (Configuration
→
ALLM RA.L.O) for 5 minutes or RAT HI Alert Limit/Occ
→ →
(Configuration ALLM RA.L.U) for 10 minutes, then an
alert will be broadcast.
T305 (Return Air Temperature Above Limit) — If the return-
air temperature is below the RAT HI Alert Limit/Occ (Config-
→ →
uration ALLM RA.H.O) for 5 minutes or RAT HI
Alert Limit/Occ (Configuration
10 minutes, then an alert will be broadcast. The alert will
automatically reset.
T308 (Return Air Relative Humidity Below Limit) — If the
unit is configured to use a return air relative humidity sensor
through the Return Air RH Sensor (Configuration
→ → →
UNIT SENS RRH.S) setting, and the measured level is
below the configurable RH Low Alert Limit (Configuration
→ →
ALLM R.RH.L) for 5 minutes, then the alert will occur.
The unit will continue to run and the alert will automatically
reset.
T309 (Return Air Relative Humidity Above Limit) — If the
unit is configured to use a return air relative humidity sensor
through the Return Air RH Sensor (Configuration
→ → →
UNIT SENS RRH.S) setting, and the measured level is
above the configurable RH High Alert Limit (Configuration
→ →
ALLM R.RH.H) for 5 minutes, then the alert will occur.
Unit will continue to run and the alert will automatically reset.
T310 (Supply Duct Static Pressure Below Limit) — If the unit
is a VAV unit with a supply duct pressure sensor and the
→
OAQ) fails if the signal from
→ →
AQ.SP IQ.O.P) input 4 to
→ →
ALLM SP.L.O] for
→ →
ALLM SP.L.U]
→ →
ALLM SP.H.O] for
→ →
ALLM SP.H.U]
→ →
ALLM SA.H.U) for
→ →
ALLM RA.H.U) for
measured supply
→
AIR.P SP) is below the configurable SP Low Alert Limit
→
(Configuration
will occur. The unit will continue to run and the alert will auto-
matically reset.
T311 (Supply Duct Static Pressure Above Limit) — If the unit
is a VAV unit with a supply duct pressure sensor and the
measured supply
→
AIR.P SP) is above the configurable SP Low Alert Limit
→
(Configuration
will occur. The unit will continue to run and the alert will auto-
matically reset.
T312 (Building Static Pressure Below Limit) — If the unit is
configured to use modulating power exhaust then a building
static pressure limit can be configured using the BP Low Alert
Limit (Configuration
→
sure (Pressures
then the alert will occur.
T313 (Building Static Pressure Above Limit) — If the unit is
configured to use modulating power exhaust then a building
static pressure limit can be configured using the BP HI Alert
Limit (Configuration
pressure (Pressures
5 minutes, then the alert will occur.
T314 (IAQ Above Limit) — If the unit is configured to use an
CO sensor and the level (Inputs
2
configurable IAQ High Alert Limit (Configuration
→
ALLM IAQ.H) for 5 minutes then the alert will occur. The
unit will continue to run and the alert will automatically reset.
A404 (Fire Shutdown Emergency Mode) — This alarm occurs
when the fire shutdown input is active (either open or closed
depending upon its configuration). If the fire shut down input is
energized (fire shutdown is in effect), or if two fire smoke
modes are incorrectly energized at the same time, a fire shut-
down mode will occur. This is an emergency mode requiring
the complete shutdown of the unit. Recovery is automatic
when the inputs are no longer on.
This alarm is usually caused by an auxiliary device that is
trying to shut down the unit (e.g., smoke detector). The input
for Fire Shutdown is at Inputs
logic configuration for this switch input can be found at
→
variable Configuration
configuration is set correctly, verify the wiring and auxiliary
device. This alarm resets automatically.
A405 (Evacuation Emergency Mode) — Unit has been placed
in the fire evacuation mode by means of the external command
for evacuation (Inputs
If the evacuation input on the CEM is energized, an evacua-
tion mode occurs which flags an alarm. This mode attempts to
lower the pressure of the space to prevent smoke from moving
into another space. This is the reverse of the Pressurization
mode. Closing the economizer, opening the return air damper,
turning on the power exhaust, and shutting down the indoor fan
will decrease pressure in the space. Recovery is automatic
when the input is no longer on.
A406 (Pressurization Emergency Mode) — Unit has been
placed in the fire pressurization mode by means of the External
command for pressurization (Inputs
If the pressurization input on the CEM is energized, a pres-
surization mode occurs which flags an alarm. This mode
attempts to raise the pressure of a space to prevent smoke
infiltration from another space. The space with smoke should
be in an Evacuation mode attempting to lower its pressure.
Opening the economizer, closing the return air damper, shut-
ting down power exhaust, and turning the indoor fan on will
increase pressure in the space. Recovery is automatic when the
input is no longer on.
92
duct static pressure
→
ALLM SP.L) for 5 minutes, then the alert
duct static pressure
→
ALLM SP.H) for 5 minutes, then the alert
→ →
ALLM BP.L). If the measured pres-
→
AIR.P BP) is below the limit for 5 minutes
→ →
ALLM BP.H). If the measured
→ →
AIR.P BP) is above the limit for
→ →
AIR.Q IAQ) is above the
→ →
FIRE FSD. The switch
→ →
SW.LG FSD.L. Verify that the
→ →
FIRE EVAC).
→ →
FIRE
→
(Pressures
→
(Pressures
→
PRES).