Carrier WeatherExpert 48N2 Controls, Start-Up, Operation, Service, And Troubleshooting page 87

• IQ.I.F = 2 (Fan On Occupied/Unoccupied) — IAQ de-
mand will always override normal indoor fan operation
and turn it on (if off) during both the occupied and unoccu-
pied period.
Economizer Min Position (Configuration  IAQ  DCV.C
 EC.MN)
This is the fully occupied minimum economizer position.
IAQ Demand Vent Min Pos. (Configuration  IAQ 
DCV.C  IAQ.M)
This configuration will be used to set the minimum damper po-
sition in the occupied period when there is no IAQ demand.
IAQ Econo Override Pos (Configuration  IAQ  AQ.SP 
IQ.O.P)
This configuration is the position that the economizer goes to
when override is in effect.
TOAQ 4-20 mA Sensor Config (Configuration  IAQ 
AQ.CF  OQ.A.C)
This is used to configure the type of outdoor sensor that will be
used for OAQ levels. It has the following configuration options:
• OQ.A.C = 0 (No Sensor) — No sensor will be used and the
internal software reference setting will be used.
• OQ.A.C = 1 (OAQ Sensor with DAQ) — An outdoor CO
sensor will be used.
• OQ.A.C = 2 (4 to 20 mA Sensor without DAQ).
OAQ Lockout Value (Configuration  IAQ  AQ.SP 
OAQ.L)
This is the maximum OAQ level above which demand con-
trolled ventilation will be disabled.
Diff. Air Quality Lo Limit (Configuration  IAQ  AQ.SP
 DAQ.L)
This is the differential CO
2
dampers will be initiated.
Diff. Air Quality Hi Limit (Configuration  IAQ  AQ.SP
 DAQ.H)
This is the differential CO
2
dampers will be at maximum and the dampers will be at the
Configuration  IAQ  DCV.C  EC.MN.
DAQ ppm Fan On Set Point (Configuration 
 IAQ  AQ.SP  D.F.ON)
This is the CO level at which the indoor fan will be turned on.
2
DAQ ppm Fan Off Set Point (Configuration  IAQ
 AQ.SP  D.F.OF)
This is the CO level at which the indoor fan will be turned off.
2
IAQ Low Reference (Configuration  IAQ  AQ.S.R  IQ.R.L)
This is the reference that will be used with a non-Carrier IAQ
sensor that may have a different characteristic curve. It rep-
resents the CO level at 4 mA.
2
IAQ High Reference (Configuration  IAQ  AQ.SR  IQ.R.H)
This is the reference that will be used with a non-Carrier IAQ
sensor that may have a different characteristic curve. It rep-
resents the CO level at 4 mA.
2
OAQ Low Reference (Configuration  IAQ  AQ.S.R  OQ.R.L)
This is the reference that will be used with a non-Carrier OAQ
sensor that may have a different characteristic curve. It rep-
resents the CO level at 4 mA.
2
OAQ High Reference (Configuration  IAQ  AQ.S.R 
OQ.R.H)
This is the reference that will be used with a non-Carrier OAQ
sensor that may have a different characteristic curve. It rep-
resents the CO level at 4 mA.
2
level at which IAQ control of the
level at which IAQ control of the
Diff. IAQ Responsiveness (Configuration  IAQ  AQ.SP
 IAQ.R)
This is the configuration that is used to select the IAQ response
curves as shown in Fig. 13.
PRE-OCCUPANCY PURGE
The control has the option for a pre-occupancy purge to refresh
the air in the space prior to occupancy.
This feature is enabled by setting Configuration  IAQ 
IAQ.P  IQ.PG to Yes.
The IAQ Purge will operate under the following conditions:
• IQ.PG is enabled
• the unit is in the unoccupied state
• Current Time is valid
• Next Occupied Time is valid
• time is within 2 hours of the next occupied period
• time is within the purge duration (Configuration 
IAQ  IAQ.P  IQ.P.T)
If all of the above conditions are met, the following logic is used:
If OAT  IQ.L.O and OAT  OCSP and economizer is avail-
able, then purge will be enabled, and the economizer will be
commanded to 100%.
2
Else, if OAT < IQ.L.O, then the economizer will be positioned
to the IAQ Purge LO Temp Min Pos (Configuration 
IAQ  IAQ.P  IQ.P.L)
If neither of the above are true, then the dampers will be posi-
tioned to the IAQ Purge HI Temp Min Pos (Configuration
 IAQ  IAQ.P  IQ.P.H)
If this mode is enabled the indoor fan and heat interlock relay
(VAV) will be energized.
IAQ Purge (Configuration  IAQ  IAQ.P  IQ.PG)
This is used to enable IAQ pre-occupancy purge.
IAQ Purge Duration (Configuration  IAQ  IAQ.P 
IQ.P.T)
This is the maximum amount of time that a purge can occur.
IAQ Purge Lo Temp Min Pos (Configuration  IAQ 
IAQ.P  IQ.P.L)
This is used to configure a low limit for damper position to be
used during the purge mode.
IAQ Purge Hi Temp Min Pos (Configuration  IAQ 
IAQ.P  IQ.P.H)
This is used to configure a maximum position for the dampers
to be used during the purge cycle.
IAQ Purge OAT Lockout Temp (Configuration  IAQ 
IAQ.P  IQ.L.O)
Nighttime lockout temperature below which the purge cycle
will be disabled.
OPTIONAL AIRFLOW STATION
The ComfortLink controls are capable of working with a factory-
installed optional airflow station that measures the amount of out-
door air entering the economizer. This flow station is intended to
measure ventilation airflows and has a limitation as to the maxi-
mum flow rate it can measure. The limits are 52,500 cfm for 75 to
105-ton units. The limit is 60,000 cfm for 120 to 150-ton units.
All configurations for the outdoor airflow station can be found
in the Configuration  ECON  CFM.C submenu. For this al-
gorithm to function, the Outdoor Air Cfm Sensor Configura-
tion (OCF.S.) must be enabled (set to 1 or 2).
There are 3 set point configurations:
O.C.MN — Econ OACFM DCV Min Flow
O.C.MX — Econ OACFM DCV Max Flow
O.C.DB — Econ OACFM MinPos Deadbd
87