Table 35 — Durablade Economizer Troubleshooting
|
| PROBLEM | CAUSE |
| REMEDY | |
Damper does not open. | Indoor (evaporator) fan is off. | 1. | Check to ensure that 24 vac is present at terminal C1 on the IFC or that | |||
|
|
|
|
|
| 24 vac is present at the IFO terminal. Check whether 24 vac is present at |
|
|
|
|
|
| |
|
|
|
|
|
| ing (see unit label diagram). |
|
|
|
|
| 2. | Check proper thermostat connection to G on the connection board. |
|
|
|
| No power to economizer motor. | 1. | Check that SW3 is properly making contact with the damper blade. Check |
|
|
|
|
|
| that SW1 is in the NC (normally closed) position. |
|
|
|
|
| 2. | Check diode D18. If diode is not functioning properly, replace D18. |
|
|
|
|
| 3. | Confirm that the economizer control board is grounded properly at |
|
|
|
|
|
| (brown wire) and at brown terminal of the economizer control board (brown |
|
|
|
|
|
| wire). The economizer motor must also be grounded properly at the negative |
|
|
|
|
|
| motor terminal (brown wire). |
|
|
|
|
| 4. | Verify SW1 and SW3 are working and wired properly (see unit label diagram). |
|
|
|
|
| 5. | Check for 24 vac input at both |
|
|
|
|
|
| 24 vac not present, check unit wiring (see unit label diagram). If 24 vac is |
|
|
|
|
|
| found in both places, check for 24 vac at the yellow terminal of the econo- |
|
|
|
|
|
| mizer control board (yellow wire). If 24 vac power is not present, replace the |
|
|
|
|
|
| economizer control board. |
|
|
|
| Economizer motor failure. | If the indoor (evaporator) fan and economizer motor are energized, verify that | |
|
|
|
|
| there is a minimum of 18 vdc at the positive motor terminal. If the motor is not | |
|
|
|
|
| operating, replace the motor. | |
Economizer operation | OAT or EC set too high. | 1. | Set at correct temperature (3 F below indoor space temperature). | |||
limited to minimum |
| 2. | Check OAT or EC by setting above outdoor temperature or humidity level. If | |||
position. |
|
| the OAT or EC switches do not close, replace OAT or EC. | |||
|
|
|
| Verify economizer control board | 1. | Perform the following tests when OAT or EC is closed, Y1 is called for and |
|
|
|
| is correctly wired and works |
| damper is at minimum position. Confirm 24 vac on gray terminal of the econ- |
|
|
|
| properly. |
| omizer control board (gray wire). If 24 vac is not present, check wiring (see |
|
|
|
|
|
| unit label diagram). |
|
|
|
|
| 2. | Verify that SW1 and SW3 are wired correctly and working properly (see unit |
|
|
|
|
|
| label diagram). |
|
|
|
|
| 3. | Check to ensure that 24 vac exists at |
|
|
|
|
|
| present, check wiring (see unit wiring label diagram). |
|
|
|
|
| 4. | Check 24 vac output at |
|
|
|
|
|
| economizer control board. |
|
|
|
| Check SAT. | 1. | After verifying that the OAT and EC settings and the economizer control |
|
|
|
|
|
| board wiring are correct, check to ensure that the 24 vac terminal of the SAT |
|
|
|
|
|
| has 24 vac (white wire). If OAT, EC, and control board are functioning and |
|
|
|
|
|
| wired properly and no 24 vac exists, check wiring (see unit label diagram). |
|
|
|
|
| 2. | If |
|
|
|
|
|
| terminal T2 on the SAT (pink wire). If 24 vac is not present, replace SAT. |
Damper does not close. | Incorrect wiring of economizer. | 1. | Verify that SW2 and SW4 are wired and working properly (see unit label | |||
|
|
|
|
|
| diagram.). |
|
|
|
|
| 2. | Check diode D19. If diode is not functioning properly, replace D19. |
|
|
|
| Verify economizer control board | 1. | After verifying that the wiring is correct, modulate the damper to the minimum |
|
|
|
| is functioning properly. |
| position. Remove the calls for G. |
|
|
|
|
| 2. | If the damper does not move, check for 24 vac at |
|
|
|
|
|
| not present, check wiring (see unit label diagram). |
|
|
|
|
| 3. | If damper still does not move, check for 24 vac at blue terminal of economizer |
|
|
|
|
|
| control board (blue wire). If 24 vac is not present, replace the economizer cir- |
|
|
|
|
|
| cuit board. |
|
|
|
| Check SAT. | 1. | After verifying that the wiring is correct and the economizer control board is |
|
|
|
|
|
| functioning properly, place the OAT or EC switch in the closed position. Place |
|
|
|
|
|
| a call for Y1 and open the damper to the fully open position. Confirm that the |
|
|
|
|
|
| 24 vac terminal of the SAT has 24 vac (white wire). If 24 vac is not present, |
|
|
|
|
|
| check wiring (see unit label diagram). |
|
|
|
|
| 2. | If |
|
|
|
|
|
| T1 on the SAT (violet wire). If 24 vac not found, replace SAT. |
|
|
|
| Economizer motor failure. | If economizer control board and SAT are functioning properly, verify that there is | |
|
|
|
|
| a minimum of 18 vdc at the positive motor terminal. If a minimum of 18 vdc is | |
|
|
|
|
| present and the motor is still not operating, replace the motor. | |
Economizer damper does | Verify that | 1. | Check voltage potential across batteries. If lower than 14 vdc, replace close- | |||
not close on power loss. | and economizer control board |
| ||||
|
|
|
| are functioning properly. |
| you check this emergency power supply on a regular basis or whenever the |
|
|
|
|
|
| filters are changed. |
|
|
|
|
| 2. | If the |
|
|
|
|
|
| properly, check for 14 vdc or higher at the blue terminal of the economizer |
|
|
|
|
|
| control board (blue wire) when power is disconnected from unit. If 14 vdc is |
|
|
|
|
|
| not present, replace the control board. |
|
| LEGEND |
|
|
| |
C1 | — | Common Power |
|
|
| |
EC | — | Enthalpy Control |
|
|
| |
IFC | — Indoor (Evaporator) Fan Contactor |
|
| |||
IFO — Indoor (Evaporator) Fan On |
|
| ||||
OAT — |
|
| ||||
PL | — | Plug |
|
|
| |
SAT — |
|
| ||||
SW | — | Economizer Position Switch |
|
|
46