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82
Building Pressure Control
The N Series
Comfort
Link controller supports several physical
rooftop configurations used to control building pressure. This
section will describe the various types used. See Table 56.
SETTING UP THE SYSTEM
The building pressure configs are found at the local display un
-
der
Configuration
BP
.
Building Pressure Configuration (BP.CF)
This configuration selects the type of building pressure control
in place.
•
BP.CF
= 0, No building pressure control
•
BP.CF
= 1, VFD controlling power exhaust to modulate
building pressure control based on building pressure sensor
•
BP.CF
= 2, VFD controlling return fan (VFD fan tracking)
Building Pressure Sensor (BP.S)
This configuration allows the reading of a building pressure
sensor when enabled. This sensor configuration is automatical
-
ly enabled when BP.CF = 1 or 2.
Building Pressure (+/-) Range (BP.R)
This configuration establishes the range in H
2
O that a 4 to 20
mA sensor will be scaled to. This configuration only allows
sensors that measure both “positive and negative” pressure.
Building Pressure Setpoint (BP.SP)
This set point is the building pressure control set point. If config
-
ured for a type of modulating building pressure control, then this
is the set point that the control will try to clamp or control to.
Building Pressure Setpoint Offset (BP.SO)
For building pressure configurations
BP.CF
=1, this is the offset
below the building pressure set point that the building pressure
must fall below to turn off and disable power exhaust control.
VFD/ Actuator Fire Speed/Pos. (BP.FS)
For
BP.CF
= 1 and 2, this configuration is the fire speed over
-
ride position when the control is in the purge and evacuation
smoke control modes.
VFD/ Actuator Minimum Speed/Pos. (BP.MN)
For
BP.CF
= 1 and 2, this configuration is the minimum VFD
speed/actuator position during building pressure operation be
-
low which the VFD/actuator may not control.
VFD Maximum Speed/Pos. (BP.MX)
For
BP.CF
= 1 and 2, this configuration is the maximum VFD
speed during building pressure operation above which the VFD
may not control.
Fan Track Learn Enable (FT.CF)
For
BP.CF
= 2, this return/exhaust control configuration selects
whether the “fan tracking” algorithm will make corrections over
time and add a “learned” offset to
FT.ST
. If this configuration is
set to NO, the unit will try to control the delta cfm value between
the supply and return VFDs only based on
FT.ST
.
Fan Track Learn Rate (FT.TM)
For
BP.CF
= 2, this return/exhaust control configuration is a
timer whereby corrections to the delta cfm operation are made.
The smaller this value, the more often corrections may be
made based on building pressure error. This configuration is
only valid when
FT.CF
= Yes.
Table 56 —
Building Pressure Control Table
* Some configurations are model number dependent.
ITEM
EXPANSION
RANGE
UNITS
CCN POINT
WRITE STATUS
BP
BUILDING PRESSURE CONFIGURATIONS
BP.CF
Building Pressure Configuration
0 to 2
BLDG_CFG
0*
BP.S
Building Pressure Sensor
Disable/Enable
BPSENS
Disable*
BP.R
Building Pressure (+/-) Range
0.10 to 0.25
H20
BP_Range
0.25
BP.SP
Building Pressure Setp.
–0.25 to 0.25
H20
BPSP
0.05
BP.SO
BP Setpoint Offset
0 to 0.5
H20
BPSO
0.05
B.V.A
VFD CONFIGURATION
BP.FS
VFD/Act. Fire Speed/Pos.
0 to 100
%
BLDGPFSO
100
BP.MN
VFD/Act. Min. Speed/Pos.
0 to 100
%
BLDGPMIN
10
BP.MX
VFD Maximum Speed
0 to 100
%
BLDGPMAX
100
FAN.T
FAN TRACKING CONFIG
FT.CF
Fan Track Learn Enable
No/Yes
DCFM_CFG
No
FT.TM
Fan Track Learn Rate
5 to 60
min
DCFMRATE
15
FT.ST
Fan Track Initial DCFM
–20,000 to 20,000
CFM
DCFMSTRT
2000
FT.MX
Fan Track Max Clamp
0 to 20,000
CFM
CDCFM_MAX
4000
FT.AD
Fan Track Max Correction
0 to 20,000
CFM
DCFM_ADJ
1,000
FT.OF
Fan Track Internal EEPROM
–20,000 to 20,000
CFM
DCFM_OFF
0
FT.RM
Fan Track Internal RAM
–20,000 to 20,000
CFM
DCFM_RAM
0
FT.RS
Fan Track Reset Internal
No/Yes
DCFMRSET
No
FAN.C
SUPPLY, RETURN FAN CFG
SCF.C
Supply Air CFM Config
1 to 2
SCFM_CFG
2
REF.C
Return/Exhaust Air CFM Config.
1 to 2
RCFM_CFG
2
SCF.S
Supply Air CFM Sensor
Disable/Enable
SCFMSENS
Disable*
RCF.S
Return Air CFM Sensor
Disable/Enable
RCFMSENS
Disable*
ECF.S
Exhaust Air CFM Sensor
Disable/Enable
ECFMSENS
Disable*
B.PID
BLDG. PRESS. PID CONFIGURATIONS
BP.TM
Bldg. Press. PID Run Rate
1 to 60
sec
BPIDRATE
10
BP.P
Bldg. Press. Prop. Gain
0 to 5
BLDGP_PG
0.5
BP.I
Bldg. Press. Integ. Gain
0 to 2
BLDGP_IG
0.5
BP.D
Bldg. Press. Deriv. Gain
0 to 5
BLDGP_DG
0.3
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 ...