Carrier 50VL-A Performance Installation Instructions Manual

Also see for Performance 50VL-A: Owner's information manual Installation instructions Installation instructions Installation instructions

Contents

46TROUBLESHOOTINGSee Table 16 for Economizer logic. An Economizer simulatorprogram is available to help with Economizer training andtroubleshooting.Economizer Preparation —This procedure is used to prepare theEconomizer for troubleshooting. No troubleshooting or testing isdone by performing the following procedure.NOTE: This procedure requires a 9--v battery, 1.2 kilo--ohmresistor, and a 5.6 kilo--ohm resistor which are not supplied withthe Economizer.1. Disconnect power at TR and TR1. All LEDs should be off.Exhaust fan contacts should be open.2. Disconnect device at P and P1.3. Jumper P to P1.4. Disconnect wires at T and T1. Place 5.6 kilo--ohm resistoracross T and T1.5. Jumper TR to 1.6. Jumper TR to N.7. If connected, remove sensor from terminals S o and +.Connect 1.2 kilo--ohm 4074EJM checkout resistor acrossterminals S o and +.8. Put 620--ohm resistor across terminals SR and +.9. Set minimum position, DCV set point, and exhaust poten-tiometers fully CCW (counterclockwise).10. Set DCV maximum position potentiometer fully CW(clockwise).11. Set enthalpy potentiometer to D.12. Apply power (24 vac) to terminals TR and TR1.Differential Enthalpy — To check differential enthalpy:1. Make sure Economizer preparation procedure has beenperformed.2. Place 620--ohm resistor across S o and +.3. Place 1.2 kilo--ohm resistor across SR and +. The Free CoolLED should be lit.4. Remove 620--ohm resistor across S o and +. The Free CoolLED should turn off.5. Return Economizer settings and wiring to normal aftercompleting troubleshooting.Single Enthalpy—To check single enthalpy:1. Make sure Economizer preparation procedure has beenperformed.2. Set the enthalpy potentiometer to A (fully CCW). The FreeCool LED should be lit.3. Set the enthalpy potentiometer to D (fully CW). The FreeCool LED should turn off.4. Return Economizer settings and wiring to normal aftercompleting troubleshooting.DCV (Demand Controlled Ventilation) and PowerExhaust—To check DCV and Power Exhaust:1. Make sure Economizer IV preparation procedure has beenperformed.2. Ensure terminals AQ and AQ1 are open. The LED for bothDCV and Exhaust should be off. The actuator should befully closed.3. Connect a 9--v battery to AQ (positive node) and AQ1(negative node). The LED for both DCV and Exhaustshould turn on. The actuator should drive to between 90and 95% open.4. Turn the Exhaust potentiometer CW until the Exhaust LEDturns off. The LED should turn off when the potentiometeris approximately 90%. The actuator should remain inposition.5. Turn the DCV set point potentiometer CW until the DCVLED turns off. The DCV LED should turn off when thepotentiometer is approximately 9--v. The actuator shoulddrive fully closed.6. Turn the DCV and Exhaust potentiometers CCW until theExhaust LED turns on. The exhaust contacts will close 30to 120 seconds after the Exhaust LED turns on.7. Return Economizer settings and wiring to normal aftercompleting troubleshooting.DCV Minimum and Maximum Position —To check the DCVminimum and maximum position:1. Make sure Economizer preparation procedure has beenperformed.2. Connect a 9--v battery to AQ (positive node) and AQ1(negative node). The DCV LED should turn on. The actu-ator should drive to between 90 and 95% open.3. Turn the DCV Maximum Position potentiometer tomidpoint. The actuator should drive to between 20 and 80%open.4. Turn the DCV Maximum Position potentiometer to fullyCCW. The actuator should drive fully closed.5. Turn the Minimum Position potentiometer to midpoint. Theactuator should drive to between 20 and 80% open.6. Turn the Minimum Position Potentiometer fully CW. Theactuator should drive fully open.7. Remove the jumper from TR and N. The actuator shoulddrive fully closed.8. Return Economizer settings and wiring to normal aftercompleting troubleshooting.Supply--Air Input—To check supply--air input:1. Make sure Economizer preparation procedure hasbeenperformed.2. Set the Enthalpy potentiometer to A. The Free Cool LEDturns on. The actuator should drive to between 20 and 80%open.3. Remove the 5.6 kilo--ohm resistor and jumper T to T1. Theactuator should drive fully open.4. Remove the jumper across T and T1. The actuator shoulddrive fully closed.5. Return Economizer settings and wiring to normal aftercompleting troubleshooting.Economizer Troubleshooting Completion —This procedure isused to return the Economizer to operation. No troubleshooting ortesting is done by performing the following procedure.1. Disconnect power at TR and TR1.2. Set enthalpy potentiometer to previous setting.3. Set DCV maximum position potentiometer to previoussetting. Set DVC Max potentiometer to fully closed (CCW)when not using a CO 2 sensor.4. Set minimum position, DCV set point, and exhaust poten-tiometers to previous settings.5. Remove 620--ohm resistor from terminals SR and +.6. Remove 1.2 kilo--ohm checkout resistor from terminals SOand +. If used, reconnect sensor from terminals SO and +.7. Remove jumper from TR to N.8. Remove jumper from TR to 1.9. Remove 5.6 kilo--ohm resistor from T and T1. Reconnectwires at T and T1.10. Remove jumper from P to P1. Reconnect device at P andP1.11. Apply power (24 vac) to terminals TR and TR1.50VL-- A