Specifications
48
Table 57 — Static Pressure Control Configuration
*Some defaults are model number dependent.
Static Pressure Configuration (SP.CF) — This variable is
used to configure the use of ComfortLink™ control for static
pressure control. It has the following options:
0(None)
— No static pressure control by ComfortLink
control. This would be used for a constant volume (CV)
application when static pressure control is not required or for a
VAV application if there will be third-party control of the VFD
or IGV. In this latter case, a suitable means of control must be
field installed.
1 (VFD Control)
— This will enable the use of ComfortLink
for static pressure control via a supply fan VFD.
Static Pressure Fan Control? (
SP.FN) — This is automatical-
ly set to Yes when SP.CF = VFD Control. When the user
would like the 4 to 20 mA output to trigger a VFD on, as op-
posed to the fan relay, SP.FN may be set to Yes when SP.CF =
none. When the control turns the fan ON, the control will send
an “SP.MX”% of the 4 to 20 mA signal to the third party VFD
control.
Static Pressure Sensor (
SP.S) — This variable enables the use
of a supply duct static pressure sensor. This must be enabled to
use ComfortLink control for static pressure control. If using a
third-party control for the VFD, this should be disabled.
Static Pressure Low Range (
SP.LO) — This is the minimum
static pressure that the sensor will measure. For most sensors
this will be 0 in. wg. The ComfortLink control will map this
value to a 4 mA sensor input.
Static Pressure High Range (
SP.HI) — This is the maximum
static pressure that the sensor will measure. Commonly this
will be 5 in. wg. The ComfortLink control will map this value
to a 20 mA sensor input.
Static Pressure Set Point (
SP.SP) — This is the static pres-
sure control point. It is the point against which the
ComfortLink control compares the actual measured supply
duct pressure for determination of the error that is used for PID
control. Generally one would set SP.SP to the minimum value
necessary for proper operation of air terminals in the condi-
tioned space at all load conditions. Too high of a value will
cause unnecessary fan motor power consumption at part-load
conditions and/or noise problems. Too low a value will result in
insufficient airflow. Additional information will be found on
page 49, under Static Pressure Reset.
VFD Minimum Speed (
SP.MN) — This is the minimum speed
for the supply fan VFD. Typically the value is chosen to main-
tain a minimum level of ventilation.
NOTE: Most VFDs have a built-in minimum speed adjustment
which must be configured for 0% when using ComfortLink
control for static pressure control.
VFD Maximum Speed (
SP.MX) —Thisisthemaximum
speed for the supply fan VFD. This is usually set to 100%.
VFD Fire Speed Override (
SP.FS) — This is the speed that
the supply fan VFD will use during the fire modes; pressuriza-
tion, evacuation and purge. This is usually set to 100%.
Static Pressure PID Config (
S.PID) — Static pressure PID
configuration can be accessed under this heading in the Con-
figuration
→
SP submenu. Under most operating conditions the
control PID factors will not require any adjustment and the
factory defaults should be used. If persistent static pressure
fluctuations are detected, small changes to these factors may
improve performance. Decreasing the factors generally reduce
the responsiveness of the control loop, while increasing the
factors increase its responsiveness. Note the existing settings
before making changes, and seek technical assistance from
Carrier before making significant changes to these factors.
Static Pressure PID Run Rate (S.PID
→
SP.TM)—This is the
number of seconds between duct static pressure readings taken
by the ComfortLink PID routine.
Static Pressure Proportional Gain (S.PID
→
SP.P)—This is
the proportional gain for the static pressure control PID control
loop.
Static Pressure Integral Gain (S.PID
→
SP.I)—This is the
integral gain for the static pressure control PID control loop.
Static Pressure Derivative Gain (S.PID
→
SP.D)—This is the
derivative gain for the static pressure control PID control loop.
STATIC PRESSURE RESET — The configuration for Static
Pressure Reset is found under Configuration
→
Unit.
ITEM TEXT DESCRIPTION RANGE UNITS CCN POINT DEFAULT
SP
SUPPLY STATIC PRESS.CFG.
SP.CF
Static Pres. VFD Control? 0, 1 STATICFG 0*
SP.FN
Static Pres. Fan Control? Yes/No STATPFAN Yes*
SP.S
Static Pressure Sensor Enable/Disable SPSENS Disable*
SP.LO
Static Press. Low Range –10 - 0 in. W.C. SP_LOW 0
SP.HI
Static Press. High Range 0 - 10 in. W.C. SP_HIGH 5
SP.SP
Static Pressure Setpoint 0 - 5 in. W.C. SPSP 1.5
SP.MN
VFD Minimum Speed 10 - 50 % STATPMIN 20
SP.MX
VFD Maximum Speed 50 - 100 % STATPMAX 100
SP.FS
VFD Fire Speed Override 0 - 100 % STATPFSO 100
S.PID
STAT.PRESS.PID CONFIGS
SP.TM
Static Press. PID Run Rate 1 - 200 sec SPIDRATE 2
SP.P
Static Press. Prop. Gain 0 - 100 STATP_PG 20
SP.I
Static Press. Intg. Gain 0 - 50 STATP_IG 2
SP.D
Static Press. Derv. Gain 0 - 50 STATP_DG 0
SP.SG
Static Press. System Gain 0 - 50 STATP_SG 1.0
ITEM EXPANSION RANGE
CCN
POINT
DEFAULT
→SENS→SP.RS
Static Press.
Reset Sensor.
Enable/
Disable
SPRSTSEN Disable