IQ.I.C = 2 (IAQ Discrete Override) — If the user sets IQ.I.C
to 2 (IAQ Discrete Override), and Configuration→SW.LG→ IAQ.L is set to OPEN, then an open switch reads low and a closed switch reads high.
If the switch reads low, no action will be taken. If the switch reads high, the economizer will immediately be commanded to the IAQ Economizer Override Position. This can be set from 0 to 100% and can be found at Configuration→IAQ→AQ.SP→ IQ.O.P.
FAN CONTROL FOR THE IAQ DISCRETE INPUT — Under Configuration→IAQ→AQ.CF, the IQ.I.F (IAQ Dis- crete Input Fan Configuration) must also be set. There are three configurations for IQ.I.F. Select the configuration which will be used for fan operation. This configuration allows the user to decide (if the supply fan is not already running), whether the IAQ discrete switch will start the fan, and in which state of occupancy the fan will start.
IQ.I.F = 0 Minimum Position Override Switch input will not start fan
IQ.I.F = 1 Minimum Position Override Switch input will start fan in occupied mode only
IQ.I.F = 2 Minimum Position Override Switch input will start fan in both occupied and unoccu- pied modes
IAQ ANALOG INPUT CONFIGURATION — This input is an analog input located on the main base board (MBB). There are 4 different functions for this input. The location of this con- figuration is at Configuration→IAQ→AQ.CF→IQ.A.C.
The functions possible for IQ.A.C are:
•0 = no IAQ analog input
•1 = IAQ analog input
•2 = IAQ analog input used to override to a set position
•3 = 4 to 20 mA 0 to 100% economizer minimum position control
•4 = 0 to 10
Options 2, 3, and 4 are dedicated for third party control. IQ.A.C = 2 (IAQ Analog Input Used to Override) — Under Configuration→IAQ→AQ.SP, set IQ.O.P (IAQ Economizer Override Position). The IQ.O.P configuration is adjustable from 0 to 100%. These configurations are also used in conjunc- tion with Configuration→IAQ→AQ.CF→IQ.A.F (IAQ 4 to 20 mA Fan Configuration). There are three configurations for IQ.A.F and they follow the same logic as for the discrete input. This configuration allows the user to decide (if the supply fan is not already running), if the IAQ Analog Minimum Position Override input will start the fan, and in which state of occupan- cy the fan will start.
IQ.A.F = 0 IAQ analog sensor input cannot start the supply fan
IQ.A.F = 1 IAQ analog sensor input can start the supply fan in occupied mode only
IQ.A.F = 2 IAQ analog sensor input can start the supply fan in both occupied and unoccupied modes
If IQ.A.F is configured to request the supply fan, then configurations D.F.ON and D.F.OF need to be set. These configuration settings are located under Configuration→ IAQ→AQ.SP and configure the fan override operation based on the differential air quality (DAQ). If DAQ rises above D.F.ON, the control will request the fan on until DAQ falls be- low D.F.OF.
NOTE: If D.F.ON is configured below DAQ.H, the unit is in occupied mode, and the fan was off, then DAQ rose above D.F.ON and the fan came on, the economizer will go to the economizer minimum position (EC.MN).
The 4 to 20 mA signal from the sensor wired to
NOTE: Configuration OAQ.U is used in the calculation of the trip point for override and can be found under Configura- tion→ IAQ→AQ.SP.
IQ.A.C = 3 (4 to 20 mA Damper Control) — This configura- tion will provide full 4 to 20 mA remotely controlled analog in- put for economizer minimum damper position. The 4 to 20 mA signal is connected to terminals
The economizer sequences can be disabled by setting Con- figuration→ECON→E.SEL to 0. Complete control of the economizer damper position is then possible by using a 4 to 20 mA economizer minimum position control or a 0 to 10
IQ.A.C = 4 (10
—This configuration will provide input for a 10
CONTROLS OPERATION
Modes — The ComfortLink™ controls operate under a hierarchy of command structure as defined by three essential elements: the System mode, the HVAC mode and the Control mode. The System mode is the top level mode that defines three essential states for the control system: OFF, RUN and TEST.
The HVAC mode is the functional level underneath the System mode which further defines the operation of the control. The mode selection process is shown in Appendix D.
The Control mode is essentially the control type of the unit (Configuration→UNIT→C.TYP). This defines from where the control looks to establish a cooling or heating mode and whether 2 stages or multiple stages of cooling capacity opera- tion are controlled.
Furthermore, there are a number of modes which operate concurrently when the unit is running. The operating modes of the control are located at the local displays under Operating Modes. See Table 42.
Currently Occupied (OCC) — This variable displays the cur- rent occupied state of the unit.
Timed Override in Effect (T.OVR) — This variable displays if the state of occupancy is currently occupied due to an override.
DCV Resetting Minimum Position (DCV) — This variable displays if the economizer position has been lowered from its maximum vent position.
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