Enthalpy Settings; Checkout; Troubleshooting; Rtu Open Control System - Bryant Preferred Series Installation Instructions Manual

ENTHALPY SETTINGS

When the OA temperature, enthalpy and dew point are below
the respective set points, the Outdoor Air can be used for econ-
omizing. Figure 51 shows the new single enthalpy boundaries
in the W7220. There are 5 boundaries (set points ES1 through
ES5), which are defined by dry bulb temperature, enthalpy and
dew point.
Refer to Table 17 for ENTH CURVE set point values.
The W7220 calculates the enthalpy and dew point using the
OA temperature and humidity input from the OA enthalpy sen-
sor. When the OA temperature, OA humidity and OA dew
point are all below the selected boundary, the economizer sets
the economizing mode to YES, economizing is available.
When all of the OA conditions are above the selected bound-
ary, the conditions are not good to economize and the mode is
set to NO.
Figure 51 shows the 5 current boundaries. There is also a high
limit boundary for differential enthalpy. The high limit bound-
ary is ES1 when there are no stages of mechanical cooling en-
ergized and HL (high limit) when a compressor stage is
energized.

CHECKOUT

Inspect all wiring connections at the economizer module's ter-
minals, and verify compliance with the installation wiring dia-
grams. For checkout, review the Status of each configured pa-
rameter and perform the Checkout tests.
NOTE: For information about menu navigation and use of the
keypad, see Interface Overview on page 29.
Power Up
After the W7220 module is mounted and wired, apply power.
Initial Menu Display
On initial start up, Honeywell displays on the first line and
economizer W7220 on the second line. After a brief pause, the
revision of the software appears on the first line and the second
line will be blank.
Power Loss (Outage or Brownout)
All set points and advanced settings are restored after any pow-
er loss or interruption.
NOTE: All settings are stored in non-volatile flash memory.
Status
Use the Status menu (see Table 11) to check the parameter val-
ues for the various devices and sensors configured.
NOTE: For information about menu navigation and use of the
keypad, see Interface Overview on page 29.
Checkout Tests
Use the Checkout menu (see page 33) to test the damper opera-
tion and any configured outputs. Only items that are config-
ured are shown in the Checkout menu.
NOTE: For information about menu navigation and use of the
keypad, see Interface Overview on page 29.
To perform a Checkout test:
1. Scroll to the desired test in the Checkout menu using the
▲ and ▼ buttons.
2. Press the (Enter) button to select the item. RUN?
appears.
3. Press the (Enter) button to start the test. The unit
pauses and then displays IN PROGRESS. When the test is
complete, DONE appears.
4. When all desired parameters have been tested, press the
(Menu Up) button to end the test.
The Checkout tests can all be performed at the time of installa-
tion or at any time during the operation of the system as a test
that the system is operable.
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage.
Be sure to allow enough time for compressor start-up and
shutdown between checkout tests so that you do not short-
cycle the compressors.

TROUBLESHOOTING

Alarms
The economizer module provides alarm messages that display
on the 2-line LCD.
NOTE: Upon power up, the module waits 60 minutes before
checking for alarms. This allows time for all the configured devic-
es (e.g. sensors, actuator) to become operational. The exception is
the SAT sensor which will alarm immediately.
If one or more alarms are present and there has been no keypad
activity for at least 5 minutes, the Alarms menu displays and
cycles through the active alarms.
You can also navigate to the Alarms menu at any time.
Clearing Alarms
Once the alarm has been identified and the cause has been re-
moved (e.g. replaced faulty sensor) the alarm can be cleared
from the display.
To clear an alarm, perform the following:
1. Navigate to the desired alarm.
2. Press the (Enter) button. ERASE? displays.
3. Press the (Enter) button. ALARM ERASED displays.
4. Press the (Menu up/Exit) button to complete the
action and return to the previous menu.
If the alarm still exists after clearing it, it is redisplayed within
5 seconds.

RTU Open Control System

For details on operating units equipped with the factory-in-
stalled RTU Open controller, refer to the "Factory-Installed
RTU Open Multi-Protocol Controller Control, Start-Up, Oper-
ation and Troubleshooting" manual.

Smoke Detectors

Smoke detectors are available as factory-installed options on
581J models. Smoke detectors may be specified for supply air
only, for return air without or with economizer, or in combina-
tion of supply air and return air. Return-air smoke detectors are
arranged for vertical return configurations only. All components
necessary for operation are factory-provided and mounted. The
unit is factory-configured for immediate smoke detector shut-
down operation; additional wiring or modifications to unit termi-
nal board may be necessary to complete the unit and smoke de-
tector configuration to meet project requirements.
Units equipped with factory-optional return-air smoke detec-
tors require a relocation of the sensor module at unit installa-
tion. See Fig. 52 for the as-shipped location.
COMPLETING RETURN-AIR
INSTALLATION
1. Unscrew the two screws holding the Return Air Smoke
Detector assembly. See Fig. 53, Step 1. Save the screws.
2. Turn the assembly 90 degrees and then rotate end to end.
Make sure that the elbow fitting is pointing down. See
Fig. 53, Step 2.
3. Screw the sensor and detector plate into its operating posi-
tion using screws from Step 1. See Fig. 53, Step 3.
4. Connect the flexible tube on the sampling inlet to the sam-
pling tube on the basepan.
37
CAUTION
SMOKE SENSOR