34
Service Configuration Selection —
The Service
Configuration Selection screen is used to configure the service
set points of the fan coil controller. See Fig. 40.
TWO-PIPE CHANGEOVER — The Two-Pipe Changeover
configuration defines if the Fan Coil is on a two-pipe system. If
the fan coil is on a two-pipe system, then it must use the same
supply and return lines for both the heating and cooling source.
A changeover temperature sensor is required.
Two-Pipe
Changeover:
Units
ASCII
Range
Disable/Enable
Default Value
Disable
FAN OPERATION — The Fan Operation configuration is
used to define how the fan will operate during occupied peri-
ods. The fan can operate in a continuous mode or cycle on a de-
mand for heat or cool. If this decision is set to continuous (1)
the fan will operate continuously during the occupied periods
and operate only during heating, cooling, and dehumidification
during unoccupied periods. If the configuration is set to auto-
matic (0), the fan will only operate only if heating, cooling or
dehumidification is required (and heating or cooling is
available).
Fan Operation:
Range
0 to 1
Default Value
1 (continuous)
NUMBER OF FAN SPEEDS — The Number of Fan Speeds
configuration is used to define the number of fan speeds wired
on the fan coil. If the fan is in automatic control, the fan will
operate at the lowest speed (0%) if dehumidification is re-
quired. The fan will operate at the highest speed (Maximum
Output %) if any stage of electric heat is operating and the sup-
ply air temperature exceeds 130 F or if any stage of DX cool-
ing is operating and the supply air temperature falls below
55 F. The fan speed will resume normal operation after all stag-
es of electric heat are deactivated and the supply air tempera-
ture falls below 100 F and if all stages of DX cooling are dis-
abled. The fan will operate as a single speed fan at the speed
desired by the user if a T57 sensor has selected manual speed
control operation.
Number of
Fan Speeds (1-3): Range
0 to 3
Default Value
3
AUTOMATIC FAN SPEED CONTROL — Automatic fan
speed control is based on a PID control which calculates the
fan speed as a value between 0 and the Maximum Output %
based upon the amount of error (P) and time (I) that the space
temperature has deviated from set point. The zone controller
evaluates the fan speed every minute. The calculated value is
displayed in the maintenance table. The Fan PID includes the
following set points: Proportional Gain, Integral Gain, Deriva-
tive Gain, and Starting Value.
Proportional Gain:Range
0.0 to 40.0
Default Value
10.0
Integral Gain:
Range
0.0 to 10.0
Default Value
3.0
Derivative Gain: Range
0.0 to 20.0
Default Value
0.0
Starting Value:
Units
%
Range
0.0 to 100.0
Default Value
0.0
COOLING TYPE — The Cooling Type configuration sets the
type of cooling that the fan coil will use. Cooling type has four
selections available: 0 = None, 1 = Modulating Valve, 2 = Two-
Position Valve, 3 = Direct Expansion Cooling.
Cooling Type:
Range
0 to 3
Default Value
0
COOLING CONTROL — The fan coil controller reads the
space temperature sensor and compares the temperature to
the current high set point. If it exceeds the set point, and cool-
ing is configured and available, the zone controller then calcu-
lates the required supply-air temperature to satisfy the given
conditions.
A Proportional / Integral / Derivative (PID) loop is used.
The modulating control function compares the submaster refer-
ence from the PID loop to the supply-air temperature and then
calculates the direction and time to position the valve. The
Cooling PID includes the following set points: Proportional
Gain, Integral Gain, Derivative Gain, and Starting Value.
Proportional Gain:Range
0.0 to 40.0
Default Value
8.0
Integral Gain:
Range
0.0 to 10.0
Default Value
0.3
Derivative Gain: Range
0.0 to 20.0
Default Value
0.0
Starting Value:
Units
Degrees F
Range
50.0 to 90.0
Default Value
65.0
NOTE: Default values are shown for Type 1 modulating
Cooling. For other cooling types, refer to the following:
Variable
2 Position and 1 Stage DX
2 Stage DX
PG
24.0
12.0
IG
0.0
0.5
Starting
65.0
65.0
Value
Fig. 39 — Set Point Screen
