516 01 3604 04
Specifications subject to change without notice.
39
TWO-SPEED FAN OPERATION
The W7220 controller has the capability to work with a sys
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tem using a 2-speed supply fan. The W7220 does not con
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trol the supply directly but uses the following input status to
determine the speed of the supply fan and controls the OA
damper to the required position.
The W (heating mode) is not controlled by the W7220 but it
requires the status to know where to position the OA damp
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er for minimum position for the fan speed.
The 2-speed fan delay is available when the system is pro
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grammed for 2-speed fan (in the System Setup menu item).
The 2-speed fan delay is defaulted to 5 minutes and can be
changed in the Advanced Setup menu item. When the unit
has a call for Y1 In and in the free cooling mode and there is
a call for Y2 In, the 2-speed fan delay starts and the OA
damper will modulate 100% open, the supply fan should be
set to high speed by the unit controller.
After the delay one of two actions will happen:
• The Y2 In call will be satisfied with the damper 100%
open and fan on high speed and the call will turn off
OR
• If the call for additional cooling in the space has not
been satisfied then the first stage of mechanical cool
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ing will be enabled through Y1 Out or Y2 Out.
CHECKOUT
Inspect all wiring connections at the economizer module’s
terminals, and verify compliance with the installation wiring
diagrams. For checkout, review the Status of each config
-
ured parameter and perform the Checkout tests.
For information about menu navigation and use of the key
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pad 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 is 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 12) 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 29.
Checkout Tests
Use the Checkout menu (see page 34) to test the damper
operation 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 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/Exit) button to end the test.
The Checkout tests can all be performed at the time of in
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stallation or at any time during the operation of the system
as a test that the system is operable.
TROUBLESHOOTING
Alarms
The economizer module provides alarm messages that dis
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play 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
devices (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 dis
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plays 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
removed (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.
NOTE: If the alarm still exists after clearing it, it is redis
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played within 5 seconds.
STATE
FAN SPEED
OCC
Low
Y1
Low
Y2
High
W
High
WARNING
ELECTRIC SHOCK HAZARD
Failure to follow this warning could result in personal in
-
jury, 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 rat
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ing plate.
If any wiring changes are required, first be sure to re
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move power from the economizer module before starting
work. Pay particular attention to verifying the power con
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nection (24 vac).
CAUTION
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.
