18
TROUBLESHOOTING
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 ash memory.
NOTE If the power goes below 18 Vac, the W7220 controller
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 congured 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.
You can also navigate to the Alarms menus at any time.
See Table 3 for the Alarms menu.
Clearing Alarms
Once the alarm has been identied and the cause has been
removed (e.g. replaced faulty sensor). The 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 you clear it, it is redisplayed
within 5 seconds.
Table 11 - 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 re-calibrate it?
The sensor is not able to be re-calibrated in the eld. However there is a menu
item under the ADVANCED menu where you are able to input a limited off set in
temperature and humidity for each sensor you have connected to the economizer.
Can I go back to factory defaults and
start over?
Under the SYSTEM SETUP menu you can change the setpoints to the factory
defaults.
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 are temperature is the temperature of air that you want to supply to the
space. In a commercial building, this is between 50 to 55
o
F (10 to 13
o
C). The mixed
are 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 even 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? 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 Control Ventilation. The VENTMAX position is set the
dame 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 com-
pletely closed in the checkout operation?
Check the damper linkage or hub to make sure the damper is able to close
completely.
How do I set the OCC? There are two setting for the OCC setting, INPUT and ALWAYS, INPUT is from the
space thermostat, if it has an occupancy output. ALWAYS is the unit in the occupied
mode, if the economizer is powered (fan on).
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 with-
out input?
The unit will remain in checkout for 10 minutes, then return to normal operation.
Manufacturer reserves the right to discontinue, or change at any time, specications, designs and prices without notice and without incurring obligations.
Form No. 18349-2P-A / JCI Form No. 1135765 Copyright MicroMetl Corporation 2014. All rights reserved.
MicroMetl Indianapolis
3035 N. Shadeland Ave., Suite 300
Indianapolis, IN 46226
1.800.MMC.HVAC (EST)
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Sparks, NV 89431
1.800.884.4662 (PST)
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Longview, TX 75602
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