Carrier 50TCA04-A07 Wiring Diagrams, Pre-Start-Up, EconoMi$er IV Troubleshooting Completion

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2.Set the Enthalpy potentiometer to A. The Free Cool LED turns on. The actuator should drive to between 20 and 80% open.

3.Remove the 5.6 kilo-ohm resistor and jumper T to T1. The actuator should drive fully open.

4.Remove the jumper across T and T1. The actuator should drive fully closed.

5.Return EconoMi$er IV settings and wiring to normal after completing troubleshooting.

EconoMi$er IV Troubleshooting Completion

This procedure is used to return the EconoMi$er IV to operation. No troubleshooting or testing 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 previ- ous setting.

4.Set minimum position, DCV setpoint, and exhaust po- tentiometers to previous settings.

5.Remove 620-ohm resistor from terminals SR and +.

6.Remove 1.2 kilo-ohm checkout resistor from termin- als SO and +. If used, reconnect sensor from termin- als 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. Recon- nect wires at T and T1.

10.Remove jumper from P to P1. Reconnect device at P and P1.

11.Apply power (24 vac) to terminals TR and TR1.

WIRING DIAGRAMS

See Fig. 65-66 for typical wiring diagrams.

PRE-START-UP

!WARNING

PERSONAL INJURY HAZARD

Failure to follow this warning could result in personal injury or death.

1.Follow recognized safety practices and wear pro- tective goggles when checking or servicing refri- gerant system.

2.Do not operate compressor or provide any electric power to unit unless compressor terminal cover is in place and secured.

3.Do not remove compressor terminal cover until all electrical sources are disconnected.

4.Relieve all pressure from system before touching or disturbing anything inside terminal box if refri- gerant leak is suspected around compressor ter- minals.

5.Never attempt to repair soldered connection while refrigerant system is under pressure.

6.Do not use torch to remove any component. Sys- tem contains oil and refrigerant under pressure. To remove a component, wear protective goggles and proceed as follows:

a.Shut off electrical power to unit.

b.Recover refrigerant to relieve all pressure from system using both high-pressure and low pressure ports.

c.Cut component connection tubing with tubing cutter and remove component from unit.

d.Carefully unsweat remaining tubing stubs when necessary. Oil can ignite when exposed to torch flame.

Proceed as follows to inspect and prepare the unit for initial start-up:

1.Remove all access panels.

2.Read and follow instructions on all WARNING, CAUTION, and INFORMATION labels attached to, or shipped with, unit.

3.Make the following inspections:

a.Inspect for shipping and handling damages such as broken lines, loose parts, or disconnected wires, etc.

b.Inspect for oil at all refrigerant tubing connec- tions and on unit base. Detecting oil generally indicates a refrigerant leak. Leak-test all refri- gerant tubing connections using electronic leak detector, halide torch, or liquid-soap solution.

c.Inspect all field-wiring and factory-wiring con- nections. Be sure that connections are completed and tight. Be sure that wires are not in contact with refrigerant tubing or sharp edges.

d.Inspect coil fins. If damaged during shipping and handling, carefully straighten fins with a fin comb.

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