Carrier CRECOMZR077A00 Installation Instructions Manual

Also see for CRECOMZR077A00: Installation instructions

Contents

25TROUBLESHOOTINGFor a list of common operating issues and concerns, seeTable 15.Power Loss (Outage or Brownout)All set points and advanced settings are restored after any pow-er loss or interruption, as all settings are stored in the Econo-mizer controller’s non-volatile flash memory.NOTE: If the power goes below 18 vac, the W7220 controllermodule assumes a power loss and the 5 minute power up delaywill become functional when power returns above 18 vac.AlarmsThe economizer module provides alarm messages that displayon the 2-line LCD.NOTE: Upon power up, the module waits several seconds beforechecking for alarms. This allows time for all the configured devic-es (e.g., sensors, actuator) to become operational.If one or more alarms are present and there has been no keypadactivity for at least 5 minutes, the Alarms menu displays andcycles through the active alarms.The Alarms menus can be navigated at any time. See Table 11for the Alarms menu.CLEARING ALARMSOnce the alarm has been identified and the cause has been re-moved (e.g., replaced faulty sensor), the alarm can be clearedfrom 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 theaction and return to the previous menu.NOTE: If an alarm still exists after it has been cleared, it will re-display within 5 seconds.Table 15 — Operating Issues and ConcernsISSUE OR CONCERN POSSIBLE CAUSE AND REMEDYMy outdoor temperature reading on the STATUS menu isnot accurateCheck 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 Irecalibrate it?The sensor is not able to be re-calibrated in the field. However, there is a menu itemunder the ADVANCED menu to input a limited offset in temperature and humidity foreach sensor that is connected to the economizer.Can I go back to factory defaults and start over? Under the SYSTEM SETUP menu, you can change the set points to the factorydefaults.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 set point for the Mixed Air Temperature(MAT)?The Mixed Air Temperature is the temperature of air to supply to the space. In acommercial building, this is between 50°F and 55°F (10°C and 13°C). Mixed air is thecombination of return air and outdoor air.I am using enthalpy sensors. Why did the control ask me toinput a dry bulb changeover temperature?If the humidity sensor in the enthalpy sensors fails, the backup algorithm in the control isto default to the temperature sensor in the enthalpy sensor.In checkout, the outdoor damper closes when I command itto open.Check the actuator linkage or rotation. In the CHECKOUT mode, the outdoor dampershould drive open or closed with the return air damper having the opposite effect.How do I set my minimum position when using a CO2sensor?The minimum position is set using the VENTMIN and VENTMAX setup in theSETPOINTS menu. VENTMIN is the minimum ventilation required when using anoccupancy sensor and VENTMAX is the minimum ventilation when not using anoccupancy sensor for Demand Control Ventilation. The VENTMAX position is set thesame as with the potentiometer on the analog economizers and is the output voltage tothe damper actuator. The range is 2 vdc closed OA damper and 10 vdc open OAdamper.What if my damper does not go completely closed in thecheckout 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 settings for the OCC setting: INPUT and ALWAYS. INPUT is from thespace thermostat, if it has an occupancy output. ALWAYS is the unit in the occupiedmode, if the economizer is powered (fan on).Does the economizer save my program values if the unitloses power? Yes, once the changes are stored in the controller they will be stored until they arechanged by the operator.If the unit is left in checkout, how long will the unit stay incheckout mode without input? The unit will remain in checkout for 10 minutes, then return to normal operation.

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