Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53500252-01
Printed in U.S.A.
Form IIK-CRECOMZR67-05
Pg 24
12-21 Replaces: IIK-CRECOMZR67-04
© 2021 Carrier
TROUBLESHOOTING
For a list of common operating issues and concerns see Table 15.
Power Loss (Outage or Brownout)
All setpoints and advanced settings are restored after any power
loss or interruption, as all settings are stored in the economizer
controller’s non-volatile flash memory.
NOTE: If power goes below 18 Vac, the W7220 module assumes
a power loss and the 5-minute power up delay will become
functional when power returns above 18 vac.
Alarms
The economizer module provides alarm messages that display on
the 2-line LCD.
NOTE: Upon power up, the module waits several seconds before
checking for alarms. This allows time for all the configured
devices (e.g. sensors, actuator) to become operational.
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.
The Alarms menus can be navigated at any time. See Table 11 for
the Alarms menu.
Clearing Alarms
Once the alarm has been identified and the cause has been re
-
moved (e.g. replaced faulty sensor). They can be cleared from the
display.
To clear an alarm, perform the following:
1. Navigate to the desired alarm.
2. Press the
button.
3. ERASE? displays.
4. Press the
button.
5. ALARM ERASED displays.
6. Press the
(Menu Up/Exit) button to complete the action
and return to the previous menu.
NOTE: If the alarm still exists after being cleared, it will redisplay
within 5 seconds.
Table 15 —
Operating Issues and Concerns
ISSUE OR CONCERN
POSSIBLE CAUSE AND REMEDY
My outdoor temperature reading on the STATUS menu is not
accurate
Check the sensor wiring:
• Enthalpy sensors are to be wired to the S-Bus terminals.
• Temperature sensors are to be wired to the OAT and MAT terminals.
If my enthalpy sensor drifts in accuracy over time, can I
recalibrate it?
The sensor cannot be re-calibrated in the field; however, a menu item under the
ADVANCED menu allows input of a limited offset in temperature and humidity for each
sensor connected to the economizer.
Will I be able to see the LCD screen when it is in the unit?
The LCD screen has a backlight that is always illuminated.
What is a good setpoint for the Mixed Air Temperature (MAT)?
The mixed air temperature is the temperature of air to supply to the space. In a
commercial building, this is between 50 and 55°F (10 to 13°C). The mixed air is the
mixing of the return air and the outdoor air.
I am using enthalpy sensors. Why did the control ask me to
input a dry bulb changeover temperature?
In the event the humidity sensor in the enthalpy sensors fails, the backup algorithm in
the control is to default to the temperature sensor in the enthalpy sensor.
In checkout, the outdoor damper closes when I command it to
open.
Check the actuator linkage or rotation. In the CHECKOUT mode, the outdoor damper
should drive open or closed with the return air damper having the opposite effect.
How do I set my minimum position when using a CO
2
sensor?
The minimum position is set using the VENTMIN and VENTMAX setup in the
SETPOINTS menu. VENTMIN is the minimum ventilation required when using an
occupancy sensor and VENTMAX is the minimum ventilation when not using an
occupancy sensor for Demand Controlled Ventilation. The VENTMAX position is set
the same as with the potentiometer on the analog economizers and is the output
voltage to the damper actuator. The range is 2 Vdc closed OA damper and 10 Vdc
open OA damper.
What if my damper does not go completely closed in the
checkout operation?
Check the damper linkage or hub to make sure the damper is able to close completely.
Does the economizer save my program values if the unit
loses power?
Yes, once the changes are stored in the controller they will be stored until they are
changed by the operator.
If the unit is left in checkout, how long will the unit stay in
checkout mode without input?
The unit will remain in checkout for 10 minutes, then return to normal operation.
