Справочник Пользователя для Honeywell W7750A
EXCEL 10 W7750A,B,C CONSTANT VOLUME AHU CONTROLLER
27
74-2958—1
Dirty Filter Monitor
The air filter in the air handler can be monitored by the W7750
and an alarm is issued when the filter media needs
replacement. The two methods of monitoring the filter are:
and an alarm is issued when the filter media needs
replacement. The two methods of monitoring the filter are:
1.
Connecting a differential pressure switch to a digital
input on the W7750A or W7750B,C.
input on the W7750A or W7750B,C.
2.
Wiring a 2 to 10V differential pressure sensor to a
voltage input on the W7750B,C. If the analog input
sensor is used, its measured value 0 to 5 inw (0 to 1.25
kPa) is compared to a user-selectable setpoint
(FltrPressStPt—valid range: 0 to 5 inw (0 to 1.25 kPa)),
and the Dirty Filter alarm is issued when the pressure
drop across the filter exceeds the setpoint.
voltage input on the W7750B,C. If the analog input
sensor is used, its measured value 0 to 5 inw (0 to 1.25
kPa) is compared to a user-selectable setpoint
(FltrPressStPt—valid range: 0 to 5 inw (0 to 1.25 kPa)),
and the Dirty Filter alarm is issued when the pressure
drop across the filter exceeds the setpoint.
Indoor Air Quality (IAQ) Override
The Excel 10 W7750 Controller provides IAQ ventilation
control using one of two different methods of detecting poor
air quality. The first is with an IAQ switch device connected to
a digital input on the W7750 Controller, where a contact
closure indicates poor air quality, and initiates the IAQ
Override mode. The device can detect poor air quality using
any desired measure such as CO
control using one of two different methods of detecting poor
air quality. The first is with an IAQ switch device connected to
a digital input on the W7750 Controller, where a contact
closure indicates poor air quality, and initiates the IAQ
Override mode. The device can detect poor air quality using
any desired measure such as CO
2
, VOC, CO, etc. The
second method, which is only available on the W7750B,C, is
through an analog input that connects to a CO
through an analog input that connects to a CO
2
sensor (2 to
10V). The measured value of CO
2
from this sensor (0 to 2000
PPM) is compared to the setpoint (IAQSetpt). When the CO
2
level is higher than the setpoint (800 PPM adjustable), the
IAQ Override is initiated. The IAQSetpt hysteresis is 50 PPM,
IAQ Override is deactivated at a CO
IAQ Override is deactivated at a CO
2
level less than 50 PPM
below setpoint.
The effect of initiating the IAQ Override mode is that the
economizer dampers are allowed to open above the standard
minimum position setting to allow more fresh air to enter the
building. See Appendix B—Sequences of Operation, for
further control details.
economizer dampers are allowed to open above the standard
minimum position setting to allow more fresh air to enter the
building. See Appendix B—Sequences of Operation, for
further control details.
Smoke Control
The Excel 10 W7750 Controller supports smoke-related
control strategies that are initiated either via a network
command (DestEmergCmd) or from a local (physically
connected) smoke detector digital input. The details of the
W7750 smoke-related control operation are described in
Appendix B—Sequences of Operation.
control strategies that are initiated either via a network
command (DestEmergCmd) or from a local (physically
connected) smoke detector digital input. The details of the
W7750 smoke-related control operation are described in
Appendix B—Sequences of Operation.
Freeze Stat
A freeze stat can be monitored by the W7750 and issue a
freeze stat alarm indicating the CVAHU is in danger of
freezing its coil. The details of the W7750 freeze stat related
control operation are described in Appendix B—Sequences of
Operation.
freeze stat alarm indicating the CVAHU is in danger of
freezing its coil. The details of the W7750 freeze stat related
control operation are described in Appendix B—Sequences of
Operation.
Modes of Operation
The possible modes of operation for the W7750 Controller are
listed in Table 5.
listed in Table 5.
Table 5. Modes Of Operation For The Excel 10 W7750 Controller .
Mode
Description
Events causing a controller to switch to this mode
Effective Occupancy (User Address: StatusOcc)
OCCUPIED
Controller is in Occupied mode
Any of the following: Network input (DestSchedOcc) containing a
time-of-day schedule flag from either the Excel 10 Zone Manager or an
L
time-of-day schedule flag from either the Excel 10 Zone Manager or an
L
ON
W
ORKS
Bus Controller; Time Clock DI, Occupancy Sensor DI; or
from Network input (DestManMode) for manual override to OCC mode.
DestManMode has the highest priority, followed by the Time Clock DI,
and then DestSchedOcc.
DestManMode has the highest priority, followed by the Time Clock DI,
and then DestSchedOcc.
STANDBY
Controller is in Standby mode
Either: (A) Network input (DestSchedOcc) containing a time-of-day
schedule flag from the Excel 10 Zone Manager or other L
schedule flag from the Excel 10 Zone Manager or other L
ON
W
ORKS
Bus node is STANDBY, or (B) Network input (DestSchedOcc) is
OCCUPIED and the Occupancy Sensor DI is UNOCCUPIED.
OCCUPIED and the Occupancy Sensor DI is UNOCCUPIED.
UNOCCUPIED Controller is in Unoccupied mode
Network input (DestSchedOcc) containing a time-of-day schedule flag
from the Excel 10 Zone Manager or L
from the Excel 10 Zone Manager or L
ON
W
ORKS
Bus, or the network
input DestManOcc has a value of UNOCCUPIED.
BYPASS
OCCUPIED
OCCUPIED
Controller is in Occupied mode through
a Bypass command
a Bypass command
This mode is derived from the schedule occupancy (DestSchedOcc)
having a state of UNOCCUPIED and a manual request for occupancy
from one of three sources. Two of these are signals originated external
to the unit, and received by DestManOcc and DestBypass. The third
source for an occupancy request is from an override button located on
a wall module. These three sources are arbitrated in a scheme
determined by the configuration parameter (Network Wins or Last-in
Wins from OvrdPriority).
having a state of UNOCCUPIED and a manual request for occupancy
from one of three sources. Two of these are signals originated external
to the unit, and received by DestManOcc and DestBypass. The third
source for an occupancy request is from an override button located on
a wall module. These three sources are arbitrated in a scheme
determined by the configuration parameter (Network Wins or Last-in
Wins from OvrdPriority).
Override Modes (User Address: StatusOvrd)
OCCUPIED
Controller occupancy mode was
overridden to Occupied mode
overridden to Occupied mode
Network input (DestManOcc) containing a time-of-day schedule
override signal of OCCUPIED from the Excel 10 Zone Manager or
other L
override signal of OCCUPIED from the Excel 10 Zone Manager or
other L
ON
W
ORKS
Bus device.
STANDBY
Controller occupancy mode was
overridden to Standby mode
overridden to Standby mode
Network input (DestManOcc) containing a time-of-day schedule
override signal of STANDBY from the Excel 10 Zone Manager or other
L
override signal of STANDBY from the Excel 10 Zone Manager or other
L
ON
W
ORKS
Bus device.