Carrier 38AUM Series, Инструкция по установке, эксплуатации и обслуживанию, Страница: 19 / 44

START-UP
38AUM Units: The compressor crankcase heater must be on for 24 hours before start-up. After the heater has been
on for 24 hours, the unit can be started. If no time elapsed since the preliminary charge step was completed, it is
unnecessary to wait the 24-hour period.
Preliminary Checks
1. Check that electric power supply agrees with unit nameplate data.
2. Verify that the compressor crankcase heater is securely in place.
3. Check that the compressor crankcase heater has been on at least 24 hours.
4. Recheck for leaks using the procedure outlined in the Pre-Start-Up section, Leak Test and Dehydration. If any leaks
are detected, repair as required. Evacuate and dehydrate as described in the Leak Test and Dehydration section.
5. Ensure that the preliminary charge has been added as described in the Pre-Start-Up section, Preliminary Charge.
6. All internal wiring connections must be tight, and all barriers and covers must be in place.
Note: The 38AUM units are factory charged with the required amount of oil. If recharging in required, use Emkarate
RL 32-3MAF for the 38AUM units.
Compressor Rotation —
On 3-phase units with scroll compressors, it is important to be certain that the compressor
is rotating in the proper direction. 38AUM units are equipped with a Comfort Alert Diagnostic Module (CADM). Alert
Code 7 indicates reverse power phasing.
To correct phase order:
1. Turn off power to the unit, tag disconnect.
2. Reverse any two of the unit power leads.
3. Reapply power to the compressor, verify correct pressures.
To verify the compressor is rotating in the proper direction:
1. Connect service gages to the suction and liquid pressure fittings.
2. Energize the compressor.
3. The suction pressure should drop and the liquid pressure should rise, as is normal on any start-up.
Compressor Overload — This overload interrupts power to the compressor when either the current or internal motor
winding temperature becomes excessive, and automatically resets when the internal temperature drops to a safe
level. This overload may require up to 60 minutes (or longer) to reset. If the internal overload is suspected of being
open, disconnect the electrical power to the unit and check the circuit through the overload with an ohmmeter or
continuity tester.
Advanced Scroll Temperature Protection (ASTP) — A label located above the terminal box identifies Copeland
Scroll compressor models that contain this technology. See Fig: - Advanced Scroll Temperature Protection (ASTP) is
a form of internal discharge temperature protection, that unloads the scroll compressor when the internal temperature
reaches approximately 149°C (300°F). At this temperature, an internal bi-metal disk valve opens and causes the scroll
elements to separate, which stops compression. Suction and discharge pressures balance while the motor continues
to run. The longer the compressor runs unloaded, the longer it must cool before the bi-metal disk resets. See Fig: -
Recommended Minimum Cool-Down Time After Compressor is Stopped.
To manually reset ASTP, the compressor should be stopped and allowed to cool. If the compressor is not stopped, the
motor will run until the motor protector trips, which occurs up to 90 minutes later. Advanced Scroll Temperature
Protection will reset automatically before the motor protector resets, which may take up to 2 hours.
Fig: - Advanced Scroll Temperature Protection Label
Page 19