Hanbell RC2-AVI Series, Manual

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● Check electrical cable connections and tightness
Procedures for RC2-AVI series’ operation
Start the compressor:
1. For loading and unloading the compressor with the inverter, it’s recommended to increase or decrease its
frequency by 1Hz at an interval of 1 to 2 seconds.
2. After starting the compressor, load the compressor to 30Hz.
3. During the period of loading to 30Hz, make sure the tendency of change in high/ low pressure is correct.
4. If there is any abnormal vibration or noise from the compressor during starting, please recheck inverter settings
until the situation has been improved.
5. Check whether the compressor oil is sufficient or not through sight glasses.
Load/unload the compressor:
1. After running at 30Hz for 2~3 minutes, changing the frequency of inverter to load/unload the compressor.
2. When changing frequency, the expansion valve should be adjusted simultaneously to meet the new flow rate.
Stop the compressor:
1. Adjust the inverter to 20Hz, and then shut down the compressor after 30 seconds of operation.
6.2 Troubleshooting
The table below shows some problems that might happen in the jobsite during commissioning or operation of the
compressor. This table will only serve as a guide for engineers to understand the situation when the problem occurs in
the job site.
PROBLEMS POSSIBLE CAUSES REMEDY / CORRECTIVE ACTION
Sudden trip of
motor thermistor
/ sensor
Low suction pressure cause low refrigerant flow rate Install liquid injection to motor coil
Refrigerant shortage Charge refrigerant
Suction filter clogged Clean filter
High suction temperature Install liquid injection to motor coil
High suction superheat Adjust the superheat less than 10K
Unstable electricity system or failure Check electricity power supply
Motor overload
Bad motor coil causing temperature rising rapidly
Poor insulation
of motor
Bad compressor motor coil. Check the coil or change the motor stator
Motor power terminal or bolt wet or frosty.
Check if the VFD settings are correct or not.
Motor power terminal or bolt bad or dusty.
Bad insulation of magnetic contactors.
Acidified internal refrigeration system.
Motor coil running long time continuously under high temperature.
Compressor restart counts too many times.
Compressor
starting failure
Voltage incorrect. Check the power supply
Voltage drop too big when starting the compressor or magnetic contactor
failure or phase failure. Check the power supply and the contactor.
Motor broken down Change the motor
Motor thermister trip. See “sudden trip of motor sensor” above
Incorrect supply power connection. Check and re-connect
Discharge or suction stop valve closed. Open the stop valve
Rotor locked Check and repair
Earth fault Check and repair
Protection device trip Check
Damaged bearings. Change bearing.
Abnormal
vibration and
noise of
compressor
Phenomenon of liquid compression. Adjust proper suction superheat
Friction between rotors or between rotor and compression chamber. Change screw rotors or/and compression chamber.
Insufficient lubrication oil.
Check the oil supply of the compressor is enough, add
some oil if necessary.
Loose internal parts.
Dismantle the compressor and change the damaged
parts.
System harmonic vibration caused by improper piping system.
Check the system piping and if possible improve it using
copper pipe.
External debris fallen into the compressor.
Dismantle the compressor and check the extent of the
damage.
Friction between slide valve and rotors.
Dismantle the compressor and change the damaged
parts.
Motor rotor rotates imbalance. Check and repair.
Motor line open Check
Compressor
does not run
Tripped overload Check the electrical connection
Screw rotors seized Replace screw rotors, bearings etc….
Motor broken Change motor.
Insufficient refrigerant.
Check for leaks. Charge additional refrigerant and adjust
suction superheat less than 10K
High discharge
temperature
Bad heat exchange in condenser Check and clean condenser
Refrigerant overcharge. Reduce the refrigerant charge
Air / moisture in the refrigerant system Recover and purify refrigerant and vacuum system