39
THIRD PARTY CONTROL
Thermostat — The method of control would be through
the thermostat inputs:
Y1 = first stage cooling
Y1 and Y2 = first and second stage cooling
W1 = first stage heating
W1 and W2 = first and second stage heating
G = supply fan
Alarm Output — The alarm output (not available when
the unit is configured for hot gas reheat), TB201-12 and
TB201-11, will provide relay closure whenever the unit is
under an alert or alarm condition.
Remote Switch — The remote switch may be configured
for three different functions. Under Configuration
→
UNIT, set
RM.CF to one of the following:
0 = no remote switch
1 = occupied/unoccupied switch
2 = start/stop switch
3 = occupancy override switch
Under Configuration
→
SW.LG, RMI.L, the remote occu-
pancy switch can be set to either a normally open or normally
closed switch input. Normal is defined as either unoccupied,
start or “not currently overridden,” respective to the RM.CF
configuration.
With RM.CF set to 1, no time schedules are followed and
the unit follows the remote switch only in determining the state
of occupancy.
With RM.CF set to 2, the remote switch can be used to shut
down and disable the unit, while still honoring timeguards on
compressors. Time schedules, internal or external, may be run
simultaneously with this configuration.
With RM.CF set to 3, the remote input may override an
unoccupied state and force the control to go occupied mode. As
with the start/stop configuration, an internal or external time
schedule may continue to control occupancy when the switch
is not in effect.
VFD Control — On VFD equipped supply fans, supply
duct static pressure control may be left under unit control or be
externally controlled. To control a VFD externally with a 4 to
20 mA signal, set SP.CF to 0, under the Configuration
→
SP
menu. This will disable the ComfortLink™ controls from vary-
ing the VFD speed in response to duct pressure with its 4 to
20 mA output.
See Appendix D and the VFD literature supplied with the
unit for VFD configurations and field wiring connections to the
VFD.
Supply Air Reset — With the installation of the Control
Expansion Module (CEM), the ComfortLink controls are capa-
ble of accepting a 4 to 20 mA signal, to reset the supply-air
temperature up to a maximum of 20 F.
Under Configuration
→
EDT.R set RS.CF to 3 (external 4
to 20 mA supply air reset control). The 4 to 20 mA input to the
control system (TB203-4 and TB203-5), will be linearized and
range from 0º to 20 F. For example, 4 mA = 0º F reset, 12 mA
= 10º F reset and 20 mA = 20º F reset.
Demand Limit Control — The term Demand Limit
Control refers to the restriction of the machine’s mechanical
cooling capacity to control the amount of power that a machine
may use.
Demand Limiting is possible via two means:
Two discrete inputs tied to demand limit set point percentages.
OR
A 4 to 20 mA input that can reduce or limit capacity linearly to
a set point percentage.
In either case, it will be necessary to install a controls expan-
sion module (CEM).
DEMAND LIMIT DISCRETE INPUTS — First, set DM.L.S
in Configuration
→
DMD.L to 1 (2 switches).
When Inputs
→
GEN.I
→
DL.S1 (Demand Switch no. 1) is
OFF, the control will not set any limit to the capacity, and
when ON, the control sets a capacity limit to the Configura-
tion
→
DMD.L
→
D.L.S1 set point.
Likewise, when Inputs
→
GEN.I
→
DL.S2 (Demand Switch
no. 2) is OFF, the control will not set any limit to the capacity,
and when ON, the control sets a capacity limit to the Configu-
ration
→
DMD.L
→
D.L.S2 set point.
If both switches are ON, Inputs
→
GEN.I
→
DL.S2 is used
as the limiter of capacity.
Under Configuration
→
SW.LG, set the logic state appropri-
ately for the action desired. Set the DL1.L and DL2.L configu-
rations. They can be set normally open or normally closed. For
example, if DL1.L is set to OPEN, the user will need to close
the switch to cause the control to limit capacity to the demand
limit 1 set point. Likewise, if DL1.L is set to CLSE (closed),
the user will need to open the switch to cause the control to
limit capacity to the demand limit 1 set point.
DEMAND LIMIT 4 TO 20 mA INPUT — Under Configu-
ration
→
DMD.L, set configuration DM.L.S to 2 (2 = 4 to
20 mA control). Under the same menu, set D.L.20 to a value
from 0 to 100 to set the demand limit range. For example, with
D.L.20 set to 50, a 4 mA signal will result in no limit to the
capacity and 20 mA signal will result in a 50% reduction in
capacity.
Economizer/Outdoor Air Damper Control —
There are multiple methods for externally controlling the econ-
omizer damper.
IAQ DISCRETE INPUT CONFIGURATION — The IAQ
(indoor air quality) discrete input configuration requires a
CEM module (optional) to be installed and an interface to a
switch input at TB204-11 and TB204-12. The state of the input
on the display can be found at Inputs
→
AIR.Q
→
IAQ.I.
Before configuring the switch functionality, first determine
how the switch will be read. A closed switch can indicate either
a low IAQ condition or a high IAQ condition. This is set at
Configuration
→
SW.LG and IAQ.L. The user can set what a
low reading would mean based on the type of switch being
used. Setting 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 two possible configurations for the IAQ discrete
input. Select 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
→
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
station is installed and outdoor air cfm can be read, the econo-
mizer 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