Carrier Weathermaster 48P030-100 Controls, Start-Up, Operation, Service, And Troubleshooting page 73

ITEM
SP SUPPLY STATIC PRESS.CFG.
SP.CF Static Pressure Config
SP.SV Staged Air Volume Control
SP.S Static Pressure Sensor
SP.LO Static Press. Low Range
SP.HI Static Press. High Range
SP.SP Static Pressure Setpoint
SP.MN VFD Minimum Speed
SP.MX VFD Maximum Speed
HS.MN VFD MinSpeed in HeatMode
HS.MX VFD MaxSpeed in HeatMode
SP.FS VFD Fire Speed Over.
SP.RS Stat. Pres. Reset Config
SP.RT SP Reset Ratio (/dF)
SP.LM SP Reset Limit in iwc ()
SP.EC SP Reset Econo.Position
S.PID STAT.PRESS.PID CONFIGS
SP.TM Static Press. PID Run Rate
SP.P Static Press. Prop. Gain
SP.I Static Pressure Intg. Gain
SP.D Static Pressure Derv. Gain
When set to enable, this will enable the use of ComfortLink con-
trols for static pressure control via a supply fan VFD. On CV
units with VFD, staged air volume, this must be set to disable.
Staged Air Volume Control (SP.SV)
This variable enabled the use of a CV unit with VFD for staged air
volume control.
Static Pressure Sensor (SP.S)
This variable enables the use of a supply duct static pressure sen-
sor. This must be enabled to use ComfortLink controls for static
pressure control. If using a third-party control for the VFD or IGV,
this should be disabled. Do not use when SP.SV is enabled.
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 controls
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 controls will
map this value to a 20 mA sensor input.
Static Pressure Set Point (SP.SP)
This is the static pressure control point. It is the point against
which the ComfortLink controls compare 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 val-
ue 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 74, 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 maintain a minimum level of ventilation.
NOTE: Most VFDs have a built-in minimum speed adjustment
which must be configured for 0% when using ComfortLink con-
trols for static pressure control. When SP.SV is enabled, the range
is 0 to 100% with the default setting of 67%.
VFD Maximum Speed (SP.MX)
This is the maximum speed for the supply fan VFD. This is usual-
ly set to 100%.
As an example, the static pressure set point (SP.SP) = 1.5 in. wg.
The current static pressure reset is set to 0.5 in. wg. The settings
Table 61 — Static Pressure Control Configuration
EXPANSION
Enable/Disable
Enable/Disable
Enable/Disable
–10 to 0
0 to 10
0 to 5
0 to 100
0 to 100
0 to 100
0 to 100
0 to 100
0 to 4
0 to 2.00
0 to 2.00
0 to 100
5 to 120
0 to 5
0 to 2
0 to 5
RANGE UNITS
in. wg
in. wg
in. wg
%
%
%
%
%
%
sec
VFD MinSpeed in HeatMode 75% (HS.MN)
For SAV operation this is the speed the fan will operate for low
heat mode.
VFD MaxSpeed in HeatMode 100% (HS.MX)
For SAV Operation this is the speed the fan will operate at in
high heat mode.
VFD Fire Speed Override (SP.FS)
This is the speed that the supply fan VFD will use during the fire
modes; pressurization, evacuation and purge. This is usually set to
100%.
Static Pressure Reset Configuration (SP.RS)
This option is used to configure the static pressure reset function.
When SP.RS = 0, there is no static pressure reset via an analog
input. When SP.RS = 1, there is static pressure reset based on the
CEM 4-20MA input and ranged from 0 to 3 in. wg. When SP.RS
= 2, there is static pressure reset based on RAT and defined by
SP.RT and SP.LM. When SP.RS = 3, there is static pressure reset
based on SPT and defined by SP.RT and SP.LM. When SP.RS =
4, there is VFD speed control where 0 mA = 0% speed and 20 mA
= 100% (SP.MN and SP.MX will override).
Static Pressure Reset Ratio (SP.RT)
This option defines the reset ratio in terms of static pressure versus
temperature. The reset ratio determines how much the static pres-
sure is reduced for every degree below set point for RAT or SPT.
Static Pressure Reset Limit (SP.LM)
This option defines the maximum amount of static pressure reset
that is allowed. This is sometimes called a "clamp."
NOTE: Resetting static pressure via RAT and SPT is primarily a
constant volume application which utilizes a VFD. The reasoning
is that there is significant energy savings in slowing down a supply
fan as opposed to running full speed with supply air reset. Main-
taining the supply air set point and slowing down the fan has the
additional benefit of working around dehumidification concerns.
Static Pressure Reset Economizer Position (SP.EC)
This option effectively resets ECONOMIN to fully occupied ven-
tilation position, to account for the drop in static pressure during
static pressure reset control. The static pressure reset for the calcu-
lation cannot be larger than the supply air static set point (SP.SP).
The calculation is as follows:
(Static Pressure Reset/SP.SP) x (ECONOSPR – ECONOMIN)
for ECONOSPR = 50% and ECONOMIN = 20%.
73
CCN POINT DEFAULT
STATICFG Disable
STGAVCFG Disable
SPSENS Disable
SP_LOW 0
SP_HIGH 5
SPSP 1.5
STATPMIN 20
STATPMAX 100
HTSPMIN 75
HTSPMAX 100
STATPFSO 100
SPRSTCFG 0
SPRRATIO 0.2
SPRLIMIT 0.75
ECONOSPR 5
SPIDRATE 15
STATP_PG 0.5
STATP_IG 0.5
STATP_DG 0.3