Bryant 582J 04-06, Installation Instructions Manual

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37
Fig. 49 — Single Enthalpy Curve Boundaries
Enthalpy Settings
When the OA temperature, enthalpy and dew point are below the
respective setpoints, the Outdoor Air can be used for economiz-
ing. Figure 49 shows the new single enthalpy boundaries in the
W7220. There are 5 boundaries (setpoints ES1 through ES5),
which are defined by dry bulb temperature, enthalpy and dew
point.
Refer to Table 17 for ENTH CURVE setpoint values.
The W7220 calculates the enthalpy and dew point using the OA
temperature and humidity input from the OA enthalpy sensor.
When the OA temperature, OA humidity and OA dew point are
all below the selected boundary, the economizer sets the econo-
mizing mode to YES, economizing is available.
When all of the OA conditions are above the selected boundary,
the conditions are not good to economize and the mode is set to
NO.
Figure 49 shows the 5 current boundaries. There is also a high lim-
it boundary for differential enthalpy. The high limit boundary is
ES1 when there are no stages of mechanical cooling energized and
HL (high limit) when a compressor stage is energized.
Checkout
Inspect all wiring connections at the economizer module’s termi-
nals, and verify compliance with the installation wiring diagrams.
For checkout, review the Status of each configured parameter and
perform the Checkout tests.
NOTE: For information about menu navigation and use of the
keypad see Interface Overview on page 28.
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 econo-
mizer 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 setpoints and advanced settings are restored after any power
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 values
for the various devices and sensors configured.
NOTE: For information about menu navigation and use of the
keypad see Interface Overview on page 28.
Checkout Tests
Use the Checkout menu (see Table 11) to test the damper opera-
tion and any configured outputs. Only items that are configured
are shown in the Checkout menu.
NOTE: For information about menu navigation and use of the
keypad see Interface Overview on page 28.
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 installation
or at any time during the operation of the system as a test that the
system is operable.
ECONOMIZING
AVAILABLE
NOT AVAILABLE
ENTHALPY
RA
HUM (%RH)
RA
TEMP
TEMPERATURE
ABSOLUTE HUMIDITY
ES5
ES4 ES3 ES2 ES1 HL
P1
(T,RH)
P2 (T,RH)
SINGLE ENTHALPY
DUAL ENTHALPY
HIGH LIMIT
WARNING
UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal injury,
property damage, or death.
Before performing service or maintenance operations on unit,
always turn off main power switch to unit and install lock(s)
and lockout tag(s). Unit may have more than one power
switch. Ensure electrical service to rooftop unit agrees with
voltage and amperage listed on the unit rating plate.
If any wiring changes are required, first be sure to remove
power from the economizer module before starting work. Pay
particular attention to verifying the power connection (24 vac).
CAUTION
Failure to follow this caution may result in damage to equip-
ment. Be sure to allow enough time for compressor start-up
and shutdown between checkout tests so that you do not short-
cycle the compressors.