Economizer Troubleshooting

Use the unit Scrolling Marquee display or a CCN device to view the economizer status display and the economizer diagnostic display (see Appendix A) for information on the economizer operation. Check the current alarms and alarm history for any economizer alarm codes and correct any causes. (See Table 11.)

Verify any unique control configurations per installed site requirements or accessories. If alarms conditions are corrected and cleared, operation of the economizer may be verified by using the Service Test mode (see Service Test section and Table 5). The following steps specify how to test the economizer using the Scrolling Marquee display. See Table 11 for general economizer service analysis.

1.Enter the Service Test main menu on the display.

2.Enter TEST and turn ON test mode. A password may be needed in order to turn ON the Service Test. The default password is 1111.

3.Return to the main level of Service Test.

4.Enter the INDP submenu and enter an initial value for ECON. This will drive the economizer damper to the specified position. Continue to adjust the ECON value to make sure the economizer opens and closes.

5.Because of a mechanical problem with the economizer, the actuator might acquire a new degree of rotation which is less than M.ANG. If this occurs, a “T414 Economizer Damper Actuator Out of Calibration” alert will be generated. This alert can only occur if the economizer is

using digital communications (Configuration ECONE.CTL = 1 or 2). The economizer calibration procedure (Service TestIND.PE.CAL) will reconfigure the actuator to the new fully closed and fully open positions. To implement the calibration procedure, change E.CAL from OFF to ON. E.CAL will remain ON as long as the calibration procedure is being implemented (as long as 5 minutes). During the calibration procedure the actuator will close fully and then open fully. After the calibration is complete, the degree of rotation should be greater than M.ANG, causing the T414 alert to clear. If the T414 alert does not clear, check the economizer damper for other mechanical problems.

6.Return to Service TestTEST and turn OFF test mode. This will cause the unit to return to normal operation.

48/50PD

Table 11 — Economizer Service Analysis

 

 

 

 

 

 

 

PROBLEM

POSSIBLE CAUSE

REMEDY

Damper Does Not Move.

Indoor Fan is off.

Check for proper VFD connections. Check that

 

 

 

 

VFD is illuminated and in Auto mode.

 

 

 

 

Unit is not configured for continuous fan operation

 

 

 

 

and there are no cooling or heating demands.

 

 

 

 

Unit is in Unoccupied mode and there is no call for

 

 

 

 

heating or cooling.

 

 

 

 

Tripped circuit breaker.

 

 

 

 

No power to the unit.

 

 

 

 

Unit is off via CCN command.

 

 

 

Actuator is unplugged at motor or at economizer board.

Check wiring connections.

 

 

 

Unit is not configured for economizer.

Configure unit for economizer per the

 

 

 

 

instructions.

 

 

 

Outdoor---air temperature is above economizer

Adjust the high temperature lockout setting if it is

 

 

 

high temperature lockout.

incorrect, otherwise, economizer is operating

 

 

 

 

correctly.

 

 

 

Outdoor---air temperature is below economizer low

Adjust the low temperature lockout setting if it is

 

 

 

temperature lockout.

incorrect, otherwise, economizer is operating

 

 

 

 

correctly.

 

 

 

Communication loss to economizer board.

Check wiring connections.

 

 

 

Damper is jammed.

Identify the obstruction and safely remove.

Economizer Operation is Limited

Minimum position is set incorrectly.

Adjust minimum position setting.

to Minimum Position.

 

 

Outdoor---air temperature is above economizer

Adjust the high temperature lockout setting

 

 

 

high temperature lockout.

if it is incorrect, otherwise, economizer is

 

 

 

 

operating correctly.

 

 

 

Outdoor---air temperature is below economizer

Adjust the low temperature lockout setting

 

 

 

low temperature lockout.

if it is incorrect, otherwise, economizer is

 

 

 

 

operating correctly.

 

 

 

Outdoor---air thermistor is faulty.

Replace outdoor---air thermistor.

 

 

 

Low suction pressure problem with a compressor.

Economizer is operating correctly, identify

 

 

 

 

compressor problem.

Economizer Position is Less

IAQ is controlling minimum damper position.

Adjust the IAQ settings if incorrect,

Than Minimum Position.

 

otherwise, the economizer is operating correctly.

 

 

 

Unit is in Unoccupied mode.

Adjust unit occupied schedule if incorrect,

 

 

 

 

otherwise, economizer is operating correctly.

 

 

 

Damper is jammed.

Identify the obstruction and safely remove.

Economizer Does Not Return

Unit is operating under free cooling.

Economizer is operating correctly.

to Minimum Position.

 

 

Damper Does Not Close on Power

Damper is jammed or spring return is backwards.

Identify the obstruction and safely remove.

Loss.

 

 

 

Remove actuator, flip it over and re---install.

Outdoor Damper Does Not Fully Close

Economizer actuator is out of calibration.

Enter Service Test mode and run the Calibrate

at 0% or Fully Open at 100%.

 

Economizer (E.CAL) procedure.

Economizer is not a configured

Unit is operating under free cooling.

Economizer is operating correctly.

minimum position

 

 

Unit fan speed is offsetting the economizer minimum

Economizer is operating correctly.

 

 

 

position to maintain proper ventilation.

 

LEGEND

 

 

 

CCN

-

Carrier Comfort Network

 

 

IAQ

-

Indoor Air Quality

 

 

VFD

-

Variable Frequency Drive

 

 

33

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Carrier 48/50PD05 manual Economizer Troubleshooting, Economizer Service Analysis

48/50PD05 specifications

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