Controls Operation; Modes - Carrier WEATHERMASTER 48/50Z030-105 Operation And Service Manual

If the switch is closed, the IAQ reading will be high and the
economizer will be commanded to the Economizer Minimum
Position. If the outdoor airflow station is installed and outdoor
air cfm can be read, the economizer will move to the Econo-
mizer Minimum Flow CFM control setting.
These settings may be adjusted and are located here:
→ →
Configuration IAQ DCV.C
→ →
Configuration IAQ DCV.C
IQ.I.C = 2 (IAQ Discrete Override) — If the user sets IQ.I.C
to 2 (IAQ Discrete Override), and Configuration
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
IQ.O.P.
FAN CONTROL FOR THE IAQ DISCRETE INPUT —
→
Under Configuration IAQ
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
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 kilo-ohms 0 to 100% economizer minimum
position control
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
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
→
EC.MN
→
O.C.MX
→
SW.LG
→ →
IAQ AQ.SP
→
AQ.CF, the IQ.I.F (IAQ Dis-
→ → →
IAQ AQ.CF IQ.A.C.
→ →
AQ.CF IQ.A.F (IAQ 4 to
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 TB12 and
TB11 is scaled to an equivalent indoor CO
parameters IQ.R.L and IQ.R.H located under the Configura-
→
→ →
tion IAQ AQ.SR menu. The parameters are defined such
that 4 mA = IQ.R.L and 20 mA = IQ.R.H. When the differen-
tial air quality DAQ (IAQ – OAQ.U) exceeds the DAQ.H set
point (Configuration
fan is on, the economizer minimum vent position (Configura-
→ →
tion IAQ DCV.C
→
is moved to the IQ.P.O configuration. When the DAQ falls be-
low the DAQ.L set point (Configuration
menu), the economizer damper is moved back to the minimum
vent position (EC.MN).
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 TB12 and TB11. The input is
processed as 4 mA = 0% and 20 mA = 100%, thereby giving
complete range control of the effective minimum position.
The economizer sequences can be disabled by removing the
enthalpy switch input at TB201-4 and not enabling any other
economizer changeover
→
ECON E.SEL. 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 kilo-ohm 0 to 100%
economizer minimum position control via configuration deci-
sions at Configuration
To disable the standard enthalpy control input function,
remove the enthalpy switch input connection at TB201-4 and
provide a jumper from TB201-3 to TB201-4 (see wiring
diagrams in Major System Components section on page 102).
IQ.A.C = 4 (10 Kohm Potentiometer Damper Control)
This configuration will provide input for a 10 kilo-ohm linear
potentiometer that acts as a remotely controlled analog input
for economizer minimum damper position. The input is pro-
cessed as 0 ohms = 0% and 10,000 ohms = 100%, thereby giv-
ing complete range control of the effective minimum position.
NOTE: For complete economizer control, the user can make
the economizer inactive by removing the enthalpy switch
connection from terminal TB201-4.

CONTROLS OPERATION

The ComfortLink™ controls operate under a
Modes —
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 Control mode is essentially the control type of the unit
→
(Configuration
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
40
→ →
IAQ AQ.SP menu) and the supply
→
EC.MN) is overridden and the damper
→
sequence at Configuration
→ →
IAQ IQ.A.C.
→
UNIT C.TYP). This defines from where
(IAQ) by the
2
→
IAQ AQ.SP
→
—