Carrier 48HE003---006 Installation Instructions Manual

Contents

59TROUBLESHOOTINGStep 1 —Unit TroubleshootingRefer to Tables 35-39 for unit troubleshooting details.Step 2 —Economi$er IV TroubleshootingSee Table 40 for EconoMi$er IV logic.A functional view of the EconoMi$er IV is shown in Fig. 69.Typical settings, sensor ranges, and jumper positions are alsoshown. An EconoMi$er IV simulator program is available fromCarrier to help with EconoMi$er IV training andtroubleshooting.Economi$er IV preparationThis procedure is used to prepare the EconoMi$er IV fortroubleshooting. No troubleshooting or testing is done byperforming the following procedure.NOTE: This procedure requires a 9-v battery, 1.2 kilo-ohmresistor, and a 5.6 kilo-ohm resistor which are not supplied withthe EconoMi$er IV.IMPORTANT: Be sure to record the positions of allpotentiometers before starting troubleshooting.1. Disconnect power at TR and TR1. All LEDs should beoff. 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 S R and +.9. Set minimum position, DCV set point, and exhaustpotentiometers 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 enthalpyTo check differential enthalpy:1. Make sure EconoMi$er IV preparation procedure has beenperformed.2. Place 620-ohm resistor across S O and +.3. Place 1.2 kilo-ohm resistor across S R and +. The FreeCool LED should be lit.4. Remove 620-ohm resistor across S O and +. The Free CoolLED should turn off.5. Return EconoMi$er IV settings and wiring to normalafter completing troubleshooting.single enthalpyTo check single enthalpy:1. Make sure EconoMi$er IV preparation procedure has beenperformed.2. Set the enthalpy potentiometer to A (fully CCW). TheFree Cool LED should be lit.3. Set the enthalpy potentiometer to D (fully CW). The FreeCool LED should turn off.4. Return EconoMi$er IV settings and wiring to normalafter completing troubleshooting.dcv (demand controlled ventilation) and power exhaustTo check DCV and Power Exhaust:1. Make sure EconoMi$er IV preparation procedure has beenperformed.2. Ensure terminals AQ and AQ1 are open. The LED forboth DCV and Exhaust should be off. The actuator shouldbe fully closed.3. Connect a 9-v battery to AQ (positive node) and AQ1(negative node). The LED for both DCV and Exhaustshould turn on. The actuator should drive to between 90and 95% open.4. Turn the Exhaust potentiometer CW until the ExhaustLED turns off. The LED should turn off when thepotentiometer is approximately 90%. The actuator shouldremain in position.5. Turn the DCV set point potentiometer CW until the DCVLED turns off. The DCV LED should turn off when thepotentiometer is approximately 9v. The actuator shoulddrive fully closed.6. Turn the DCV and Exhaust potentiometers CCW until theExhaust LED turns on. The exhaust contacts will close 30to 120 seconds after the Exhaust LED turns on.7. Return EconoMi$er IV settings and wiring to normalafter completing troubleshooting.dcv minimum and maximum positionTo check the DCV minimum and maximum position:1. Make sure EconoMi$er IV preparation procedure has beenperformed.2. Connect a 9-v battery to AQ (positive node) and AQ1(negative node). The DCV LED should turn on. Theactuator should drive to between 90 and 95% open.3. Turn the DCV Maximum Position potentiometer tomidpoint. The actuator should drive to between 20 and80% open.4. Turn the DCV Maximum Position potentiometer to fullyCCW. The actuator should drive fully closed.5. Turn the Minimum Position potentiometer to midpoint.The actuator should drive to between 20 and 80% open.6. Turn the Minimum Position Potentiometer fully CW. Theactuator should drive fully open.7. Remove the jumper from TR and N. The actuator shoulddrive fully closed.8. Return EconoMi$er IV settings and wiring to normalafter completing troubleshooting.supply--air inputTo check supply-air input:1. Make sure EconoMi$er IV preparation procedure has beenperformed.2. Set the Enthalpy potentiometer to A. The Free Cool LEDturns on. The actuator should drive to between 20 and80% open.3. Remove the 5.6 kilo-ohm resistor and jumper T to T1. Theactuator should drive fully open.4. Remove the jumper across T and T1. The actuator shoulddrive fully closed.5. Return EconoMi$er IV settings and wiring to normalafter completing troubleshooting.economi$er IV troubleshooting completionThis procedure is used to return the EconoMi$er IV to operation.No troubleshooting or testing is done by performing thefollowing procedure.1. Disconnect power at TR and TR1.2. Set enthalpy potentiometer to previous setting.48HE,HJ