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38
IAQ.L
to OPEN means that when the switch is open, the input
will read LOW. When the switch is closed, the input will read
HIGH. Setting
IAQ.L
to CLSE (closed) means that when the
switch is closed, the input will read LOW, and therefore, when the
switch is open, the switch will read HIGH.
There are 2 possible configurations for the IAQ discrete input. Se
-
lect item
Configuration
IAQ
AQ.CF
IQ.I.C
and configure
for either 1 (IAQ Discrete) or 2 (IAQ Discrete Override).
IQ.I.C = 1 (IAQ Discrete)
If the user sets
IQ.I.C
to 1 (IAQ Discrete), and the switch logic
(
Configuration
IAQ
SW.LG
IAQ.L
) is set to OPEN,
then an open switch reads LOW and a closed switch reads
HIGH.
If the switch is open, the economizer will be commanded to the
IAQ Demand Vent Minimum Position. If the outdoor flow sta
-
tion is installed and outdoor air cfm can be read, the economiz
-
er will move to the IAQ Demand Vent Minimum Flow CFM
control setting.
These settings may be adjusted and are located here:
Configuration
IAQ
DCV.C
IAQ.M
Configuration
IAQ
DCV.C
O.C.MN
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
EC.MN
Configuration
IAQ
DCV.C
O.C.MX
IQ.I.C = 2 (IAQ Discrete Override)
If the user sets
IQ.I.C
to 2 (IAQ Discrete Override), and
Con
-
figuration
IAQ
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 3
configurations for
IQ.I.F
.
Select the configuration that will be
used for fan operation. This configuration allows the user to
decide whether the IAQ discrete switch will start the fan (if the
supply fan is not already running), and in which state of occu
-
pancy the fan will start.
IAQ ANALOG INPUT CONFIGURATION
This is an analog input located on the main base board (MBB).
There are 4 different functions for this input. The location of this
configuration 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 10,000 ohms 0 to 100% economizer minimum posi
-
tion 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 Econ
-
omizer Override Position). The
IQ.O.P
configuration is adjust
-
able from 0 to 100%. These configurations are also used in
conjunction with
Configuration
IAQ
AQ.CF
IQ.A.F
(IAQ 4 to 20 mA Fan Configuration). There are 3 configura
-
tions for
IQ.A.F
, and they follow the same logic as for the dis
-
crete 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
occupancy the fan will start.
.
If
IQ.A.F
is configured to request the supply fan, then configu
-
rations
D.F.ON
and
D.F.OF
need to be set. These configura
-
tion settings are located under
Configuration
IAQ
AQ.SP
,
and configure the fan override operation based on the differen
-
tial air quality (DAQ). If DAQ rises above
D.F.ON
,
the control
will request the fan on until DAQ falls below
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 TB201-8 and
TB201-7 is scaled to an equivalent indoor CO
2
(IAQ) by the pa
-
rameters
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 differential air
quality DAQ (IAQ –
OAQ.U
) exceeds the
DAQ.H
set point (
Con
-
figuration
IAQ
AQ.SP
menu) and the supply fan is on, the
economizer
minimum
vent
position
(
Configura
-
tion
IAQ
DCV.C
EC.MN
) is overridden and the damper is
moved to the
IQ.O.P
configuration. When the DAQ falls below
the
DAQ.L
set point (
Configuration
IAQ
AQ.SP
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 configuration will provide full 4 to 20 mA remotely con
-
trolled analog input for economizer minimum damper position.
The 4 to 20 mA signal is connected to terminals TB201-8 and
TB201-7. 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 unplugging the
enthalpy switch input and not enabling any other economizer
changeover sequence at
Configuration
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 10,000-ohm 0 to 100% economizer minimum
position control via configuration decisions at
Configura
-
tion
IAQ
AQ.CF
IQ.A.C
.
To disable the standard enthalpy control input function, unplug
the enthalpy switch and provide a jumper from TB201-6 to
TB201-5 (see wiring diagrams in Major System Components
section on page 134).
IQ.A.C = 4 (10,000 ohm Potentiometer Damper Control)
This configuration will provide input for a 10,000-ohm linear
potentiometer that acts as a remotely controlled analog input for
economizer minimum damper position. The input is processed
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 unoccupied modes
IQ.A.F
= 0 IAQ analog sensor input cannot start the sup
-
ply 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
Summary of Contents for WeatherExpert 48N2
Page 135: ...135 Fig 18 48 50N Typical Power Schematic Nominal 075 Ton Unit Shown ...
Page 136: ...136 Fig 19 48 50N Typical Power Schematic Nominal Ton 90 150 Units Shown ...
Page 137: ...137 Fig 20 48 50N Main Base Board Input Output Connections ...
Page 138: ...138 Fig 21 48 50N RXB EXB CEM Input Output Connections a48 9307 ...
Page 139: ...139 Fig 22 48 50N EXV SCB Input Output Connections a48 9308 ...
Page 140: ...140 Fig 23 48N Typical Modulating Gas Heat Unit Control Wiring ...
Page 141: ...141 Fig 24 50N Typical Electric Heat Unit Control Wiring ...
Page 144: ...144 Fig 27 48N Typical Gas Heat Section Wiring Nominal Ton 120 to 150 Units ...
Page 145: ...145 Fig 28 48 50N Typical Power Component Control Wiring 460 v ...
Page 146: ...146 Fig 29 48 50N Component Control Wiring 575 v Nominal Ton 075 to 150 Units ...
Page 147: ...147 Fig 30 48 50N Component Arrangement Power Box ...
Page 148: ...148 Fig 31 48 50N Component Arrangement Control Box ...
Page 240: ...240 APPENDIX D VFD INFORMATION CONT Fig G VFD Bypass Wiring Diagram WHEN USED ...