Carrier WeatherExpert 48N2 Controls, Start-Up, Operation, Service And Troubleshooting Instructions page 124


SENS RRH.S) setting, and the measured level is below the
configurable RH Low Alert Limit (Configuration
 
IAQ ALLM R.RH.L) for 5 minutes, then the alert will oc-
cur. The unit will continue to run and the alert will automatical-
ly 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

SENS RRH.S) setting, and the measured level is above the
configurable RH High Alert Limit (Configuration
 
IAQ ALLM R.RH.H) for 5 minutes, then the alert will oc-
cur. Unit will continue to run and the alert will automatically
reset.
T310 (Supply Duct Pressure Below Limit) — If the unit is a
VAV unit with a supply duct pressure sensor and the measured
supply duct static pressure (Pressures
the configurable SP Low
  
tion IAQ ALLM SP.L) for 5 minutes, then the alert will
occur. The unit will continue to run and the alert will automati-
cally reset.
T311 (Supply Duct Pressure Above Limit) — If the unit is a
VAV unit with a supply duct pressure sensor and the measured
supply duct static pressure (Pressures
the configurable SP Low
 IAQ  ALLM  SP.H) for 5 minutes, then the alert will oc-
tion
cur. The unit will continue to run and the alert will automatically
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
the measured pressure (Pressures
limit for 5 minutes 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
measured pressure (Pressures
it for 5 minutes, then the alert will occur.
T314 (IAQ Above Limit) — If the unit is configured to use a
CO sensor and the level (Inputs
2
configurable IAQ High Alert Limit (Configuration
 
IAQ ALLM IAQ.H) for 5 minutes then the alert will oc-
cur. The unit will continue to run and the alert will automatical-
ly reset.
T316 (OAT Below Limit) — If the outside-air temperature
measured by the OAT thermistor (Temperatures
OAT) is below the configurable OAT Low Alert Limit (Con-
  
figuration IAQ ALLM
alert will be broadcast.
T317 (OAT Above Limit — If the outside-air temperature
measured by the OAT thermistor (Temperatures
OAT) is above the configurable OAT High Alert Limit
 
(Configuration IAQ ALLM
the alert will be broadcast.
T318 (SP Not Holding Setpoint) — If the static pressure (Pres-
 AIR.P  SP)
sures is outside
 SP  SP.SP ± Configuration  IAQ  PROG  PG.SP this
tion
alert will be logged. Recovery is automatic. The reason for the alert
is that the static pressure set point is not being held by the supply.
T319 (BP Not Holding Setpoint) — If the building pressure
 AIR.P  BP) is outside the range Configura-
(Pressures
 BP  BP.SP
tion ±
PG.BP this alert will be logged. Recovery is automatic. The
reason for the alert is that the building pressure set point is
not being held by the power exhaust fan.
T320 (DELTACFM Not Holding Setpoint) — If the delta
 
cfm (Inputs CFM S.CFM - Inputs
outside the range

UNIT
 
AIR.P SP) is below
Alert Limit (Configura-
 AIR.P  SP) is above
Alert Limit (Configura-
  
IAQ ALLM BP.L). If
 
AIR.P BP) is below the
  
IAQ ALLM BP.H). If the
 
AIR.P BP) is above the lim-
 
AIR.Q IAQ) is above the

AIR.T
OAT.L) for 5 minutes then the

AIR.T

OAT.H) for 5 minutes then
the range Configura-
 IAQ  PROG 
Configuration
 
CFM R.CFM) is
 
Inputs CFM D.CFM

Configuration

logged. Recovery is automatic. The reason for the alert is that
the delta cfm is not being held by the return.
T321 (SH_A1 Not Holding Setpoint)
T322 (SH_A2 Not Holding Setpoint) — If the circuit A su-
perheat (Temperatures
the range Run Status
 
tion IAQ PROG

ery is automatic. The reason for this alert is that the superheat
set point is not being held by EXV.

T323 (SH_B1 Not Holding Setpoint)
T324 (SH_B2 Not Holding Setpoint) — If the circuit B super-
heat (Temperatures
range Run Status
 
tion IAQ PROG
ery is automatic. The reason for this alert is that the superheat
set point is not being held by EXV.
T325 (Circuit A High Pressure Drop Detected –
Check Filter Drier)
T326 (Circuit B High Pressure Drop Detected –
Check Filter Drier) — Alert codes 325 and 326 are for circuits
A and B respectively. If the pressure difference DP.A-LP.A (or
DP.B-LP.B) on the corresponding circuit is outside of ± Con-

figuration IAQ
Recovery is automatic. This alert is an indication the filter drier
may be dirty and need to be changed.
T327 (Heat Not Holding Setpoint) — If the leaving air tem-
perature (Temperatures

Run Status VIEW

PROG PG.MH this alert will be logged. Recovery is auto-
matic. The reason for the alert is that the heat control point is
not being held.
T329 (Possible MLV/HGBP Failure Detected) — If the cir-
cuit A discharge pressure (Pressures
reduced by Configuration
will be logged. Recovery is automatic. The reason for the alert
is that the MLV/HGBP may not be functioning properly.
T335 (Excess Outdoor Air) — When the control detects a
stuck or jammed actuator, it shall compare the stuck position to
the command position to log additional alerts. If the stuck po-
sition > commanded position, the alert is set.
A400 (Hydronic Freezestat Trip) — If the freezestat for the

hydronic coil trips, the unit goes into emergency mode and
does not allow cooling or heating. The economizer goes to 0%
open. Supply fan operation is enabled. Recovery is automatic
when the switch goes off.
A404 (Fire Shut Down Emergency Mode [fire-smoke]) —

If the fire shutdown input is energized (fire shutdown is in ef-
fect), or if two fire smoke modes are incorrectly energized at
the same time, a Fire Shutdown 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.

A405 (Evacuation Emergency Mode) — If the evacuation in-
put on the CEM is energized, an evacuation 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) — If the pressuriza-
tion input on the CEM is energized, a pressurization 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, clos-
ing the return-air damper, shutting down power exhaust, and
±
124
 
IAQ PROG PG.DC this alert will be
 
REF.T SH_A1, SH_A2) is outside
  
EXVS CTRL C.SHS ± Configura-

PG.SH this alert will be logged. Recov-
 
REF.T SH.B1, SH.B2) is outside the
  
EXVS CTRL C.SHS ± Configura-

PG.SH this alert will be logged. Recov-
 
PROG PG.FD this alert will be logged.
 
AIR.T S.G.LS) is outside the range

HT.C.P ± Configuration

REF.P
  
IAQ PROG
 
IAQ

DP.A) is not
PG.ML this alert