65
D = K *
BP.D
* (error – error computed last time through
the PID)
VFD speed reference (clamped between
BP.MN
and
BP.MX
%) = P + I + D
Smoke Control Modes —
There are four smoke con-
trol modes that can be used to control smoke within areas ser-
viced by the unit: Pressurization mode, Evacuation mode,
Smoke Purge mode, and Fire Shutdown. Evacuation, Pressur-
ization and Smoke Purge modes require the controls expansion
module (CEM). The Fire Shutdown input is located on the
main base board (MBB) on terminals TB5-10 and 11. The unit
may also be equipped with a factory-installed return air smoke
detector that is wired to TB5-10 and 11 and will shut the unit
down if a smoke condition is determined. Field-monitoring
wiring can be connected to terminal TB5-8 and 9 to monitor
the smoke detector. Inputs on the CEM board can be used to
put the unit in the Pressurization, Evacuation, and Smoke
Purge modes. These switches or inputs are connected to TB6 as
shown below. Refer to Major System Components section on
page 103 for wiring diagrams.
Pressurization — TB5-12 and 13
Evacuation — TB5-12 and 14
Smoke Purge — TB5-12 and 15
Each mode must be energized individually on discrete in-
puts and the corresponding alarm is initiated when a mode is
activated. The fire system provides a normally closed dry con-
tact closure. Multiple smoke control inputs, sensed by the con-
trol will force the unit into a Fire Shutdown mode.
FIRE-SMOKE INPUTS — These discrete inputs can be
found on the local display under
Inputs
FIRE
.
Fire Shutdown Mode — This mode will cause an immediate
and complete shutdown of the unit.
Pressurization Mode — This mode attempts to raise the pres-
sure of a space to prevent smoke infiltration from an adjacent
space. Opening the economizer (thereby closing the return air
damper), shutting down power exhaust and turning the indoor
fan on will increase pressure in the space.
Evacuation Mode — This mode attempts to lower the pres-
sure of the space to prevent infiltrating an adjacent space with
its smoke. Closing the economizer (thereby opening the return-
air damper), turning on the power exhaust and shutting down
the indoor fan decrease pressure in the space.
Smoke Purge Mode — This mode attempts to draw out
smoke from the space after the emergency condition. Opening
the economizer (thereby closing the return-air damper), turning
on both the power exhaust and indoor fan will evacuate smoke
and bring in fresh air.
AIRFLOW CONTROL DURING THE FIRE-SMOKE
MODES — All non-smoke related control outputs will get
shut down in the fire-smoke modes. Those related to airflow
will be controlled as explained below. The following matrix
specifies all actions the control shall undertake when each
mode occurs (outputs are forced internally with CCN priority
number 1 - “Fire”).
*“FSO” refers to the supply VFD fire speed override configurable
speed.
RELEVANT ITEMS
The economizer’s commanded output can be found in
Outputs
ECON
ECN.C
.
The configurable fire speed override for supply fan VFD is in
Configuration
SP
SP.FS
.
The supply fan relay’s commanded output can be found in
Outputs
FANS
S.FAN
.
The supply fan VFD’s commanded speed can be found in
Outputs
FANS
S.VFD
.
Indoor Air Quality Control
The indoor air quality
(IAQ) function will admit fresh air into the space whenever
space air quality sensors detect high levels of CO
2
.
When a space or return air CO
2
sensor is connected to the
unit control, the unit’s IAQ routine allows a demand-based
control for ventilation air quantity, by providing a modulating
outside air damper position that is proportional to CO
2
level.
The ventilation damper position is varied between a minimum
ventilation level (based on internal sources of contaminants
and CO
2
levels other than from the effect of people) and the
maximum design ventilation level (determined at maximum
populated status in the building). Demand controlled ventila-
tion (DCV) is also available when the
Comfort
Link unit is con-
nected to a CCN system using ComfortID™ terminal controls.
This function also provides alternative control methods for
controlling the amount of ventilation air being admitted,
including fixed outdoor air ventilation rates (measured as cfm),
external discrete sensor switch input and externally generated
proportional signal controls.
The IAQ function requires the installation of the factory-
option economizer system. The DCV sequences also require
the connection of accessory (or field-supplied) space or return
air CO
2
sensors. Fixed cfm rate control requires the factory-
installed outdoor air cfm option. External control of the
ventilation position requires supplemental devices, including a
4 to 20 mA signal, a 10,000 ohms potentiometer, or a discrete
switch input, depending on the method selected. Outside air
CO
2
levels may also be monitored directly and high CO
2
economizer restriction applied when an outdoor air CO
2
sensor
is connected. (The outdoor CO
2
sensor connection requires
installation of the CEM.)
The
Comfort
Link control system has the capability of DCV
using an IAQ sensor. The indoor air quality (IAQ) is measured
using a CO
2
sensor whose measurements are displayed in parts
per million (ppm). The IAQ sensor can be field-installed in the
return duct. There is also an accessory space IAQ sensor that
can be installed directly in the occupied space. The sensor must
provide a 4 to 20 mA output signal and must include its own
24-v supply. The sensor connects to terminal TB5-6 and 7. Be
sure to leave the 182-ohm resistor in place on terminals 6 and 7.
ITEM
EXPANSION
RANGE
CCN
POINT
WRITE
STATUS
FIRE
FIRE-SMOKE INPUTS
FSD
Fire Shutdown Input
ALRM/NORM FSD
forcible
PRES
Pressurization Input
ALRM/NORM PRES forcible
EVAC
Evacuation Input
ALRM/NORM EVAC forcible
PURG
Smoke Purge Input
ALRM/NORM PURG forcible
DEVICE
PRESSURIZATION PURGE EVACUATION
FIRE
SHUTDOWN
Economizer
100%
100%
0%
0%
Indoor Fan —
VFD
ON/FSO*
ON/FSO*
OFF
OFF
Power Exhaust
OFF
ON/FSO*
ON/FSO*
OFF
Heat Interlock
Relay
ON
ON
OFF
OFF
Содержание Carrier Weathermaker 48A2
Страница 105: ...105 Fig 20 Typical Main Control Box Wiring Schematic 48 50A2 A3 A4 A5 Units...
Страница 106: ...106 Fig 21 Typical Auxiliary Control Box Wiring Schematic...
Страница 107: ...107 Fig 22 Typical 2 Stage Gas Heat Wiring Schematic Size 060 Units Shown a48 8357...
Страница 108: ...108 TO NEXT PAGE Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown A48 7296...
Страница 109: ...109 Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown cont A48 8358...
Страница 110: ...110 Fig 24 Typical Electric Heat Control Schematic 50 Series Size 060 Units Shown a50 8228...
Страница 111: ...111 Fig 25 Typical Power Schematic 48 50A2 A3 A4 A5 060 Unit Shown...
Страница 112: ...112 Fig 26 Typical Low Ambient Controls Option Wiring...
Страница 113: ...113 Fig 27 Typical Small Chassis Component Location Size 020 035 Units...
Страница 114: ...114 Fig 28 Typical Large Chassis Component Locations Size 040 060 Units...
Страница 118: ...118 Fig 30 Economizer Control Board ECB1 and VAV Control Board ECB2 A48 7706...
Страница 142: ...142 A48 3733 Fig 56 Main Burner Removal...
Страница 176: ...176 APPENDIX C VFD INFORMATION cont Fig F Internal Enclosure Fan Replacement A48 7716...
