PREMIUM PRF3XT (01) PDF DOCUMENT

Feature	Description
Door	Integrated Foaming Door with painting sheet metal and simple, beautiful recessed handle.
Gasket seal for the door	Recessed door gasket seal, easy to be discharged and cleaned.
Hinge	Plastic material, simple and practically.
Accessory	One shelf and one drip tray inside.
Structure	Front, Left and right side shell compose to whole “U” shape shell, with aluminum internal tank with cotton ginning, and unitary plastic linear mouth. It has inside hidden evaporator and condenser, and unitary foaming insulation.

Specification	PRF047XW	PRF071XW/PRF3X-3XT
Net Capacity (L)	47	71
Voltage (V)	115	115
Frequency (Hz)	60	50
Refrigerant	R134a	R134a
Refrigerant Amount (g)	38g	45g

To ensure safety during maintenance, you must obey the following basic attentions:

1) During service:

– Pay attention to the flame or ignition nearby, particularly after welding using gas. You must turn off the flame first, then you can do other maintenance work, because the refrigerant will produce toxic air when it touches flame, sparkle or capacitor.

– Do not do the welding work in an airtight or bad air circulation room.

– When discharging the refrigerant, you must keep the room in good air circulation condition.

– When cutting the suction pipe or discharging pipe of the compressor, pay attention to the surplus refrigerant and internal pressure in the cooling system pipe.

2) Unplug the unit:

– When you are ready to proceed with maintenance, you must first unplug the freezer to ensure safety.

3) Avoid electrical shock:

– Normally when proceeding with maintenance, you must open the power supply first. But if you must check the field wiring or the component of the unit with the power supply on, you must be very careful and not touch the live parts. If you find out the wiring is aged, please replace it in time.

4) Correct use of components:

– If the component is damaged and needs to be replaced, be sure to replace it with a component of the same model. Do not use other models or other brand components, and do not use a changed component.

5) Correct use of service tools:

– Ensure to use the appropriate service tool right. Otherwise, it will cause bad electrical contact or loose fixing, and an incident will happen.

6) Wiring connection:

– When re-connecting the cut wire, be sure to use a soldering method or terminal connection, and then wrap the connection point with insulation tape to ensure a good connection.

7) Insulation resistance measure:

– After completing the service and assembly, you must use a multi-meter to measure the insulation resistance. If it is greater than 1 million ohm, then you can plug in the unit.

8) Grounding test:

– After maintenance, use the multimeter to measure the grounding resistance to ensure the grounding resistance is less than 0.1 ohm.

9) Pay attention to the child or infant nearby:

– When performing maintenance, do not let the child or the infant nearby.

10) Cleaning:

– After service, do the necessary cleaning work and tell the customer the necessary precautions.

The electrical system consists of the following components connected as per the electrical diagram:

– Power Plug (L, E, N)

– Thermostat

– Overload Protector

– PTC Starter

– Compressor

Wiring connects these components, including ground wires (yellow/green). Please note, some units may be without a RUNNING CAPACITOR.

The cooling system circulates refrigerant to cool the unit. The main components and flow are:

1. The Compressor pressurizes the refrigerant.

2. The hot, high-pressure gas flows to the Condenser, where it releases heat and turns into a liquid.

3. The liquid refrigerant passes through a Dry Filter to remove moisture and impurities.

4. It then flows through a narrow Capillary tube, which lowers its pressure and temperature.

5. The cold, low-pressure liquid enters the Evaporator, where it absorbs heat from the inside of the fridge, causing it to boil and turn back into a gas.

6. The gas then flows back to the compressor through the Air Suction Pipe to start the cycle again.

Note: The arrow direction in the system diagram indicates the flowing direction of the refrigerant.

No.	Parts Name	PRF047XW	PRF071XW/PRF3X-3XT
1	Door	1	1
2	Hinge	2	2
3	Shelf	1	2
4	Freezer Cabinet	1	1
5	Thermostat cover	1	1
6	Compressor base	1	1
7	Condensate Water Drain cap	1	1
8	Fixing feet	2	2

When replacing components, you must unplug the unit first for safety.

1. Unscrew the fixing screw of the thermostat box.

2. Remove the thermostat box.

3. Remove the old thermostat.

4. Install the new thermostat with the same model.

5. Reinstall the whole thermostat box with the same fixing screw.

When replacing components, you must unplug the unit first for safety.

1. Remove the clamp of the connecting terminal cover of the compressor and the terminal cover.

2. Toward the vertical direction, remove the broken-down starter or overload protector.

3. Install back the new starter or overload protector.

4. Fix back the terminal box cover and its clamp.

When replacing components, you must unplug the unit first for safety.

1. Remove the old door gasket seal from the groove of the door liner.

2. Install the new gasket seal into the four sides of the groove, installing it as evenly as possible.

3. Open and close the door several times to ensure that the door is sealed.

When replacing components, you must unplug the unit first for safety.

a) First, cut the welding point of the technical pipe of the compressor to discharge the refrigerant inside the cooling system. Then, weld the old point to disconnect the pipe to the compressor. Remove the compressor to replace it with a new one. Pay attention to replace it with a new refrigerant dry filter.

b) Install the new compressor. Weld the high pressure side and low pressure side pipe to the compressor. Check the system for leakage. After completing, vacuum the cooling system. Charge the correct amount of refrigerant into the system from the low pressure side pipe. After this, run the unit to check if the cooling performance is ok or not, then weld and close the technical pipe.

If there is no frost, perform a leakage detection.

A) If a leakage point is found, first cut off the low pressure pipe to discharge the remaining refrigerant. Then, clean the pipe, replace it with a new dry filter, weld it again, recharge the refrigerant, and perform leakage detection again.

B) If no leakage can be found, cut off the low pressure pipe. If no refrigerant is omitted, recharge the refrigerant and perform leakage detection again. If refrigerant is omitted, it means the compressor suction is normal. Cut off the high pressure pipe and charge the condenser pipe with pressurized nitrogen. If no air is present at the low pressure side, the pipe is blocked; replace the blocked parts and clean the system pipe. If there is no air suction at the compressor low pressure side when the high pressure pipe is cut, it means the air compression of the compressor is not good; please replace the compressor.

First, perform a leakage detection.

A) If the leakage point is confirmed, cut off the low pressure pipe. If a little refrigerant air spurts out, it means the system is leaking slowly. You should repair the welding of the cut pipe and the leakage point, clean the system pipe with high pressure nitrogen, and replace the dry filter. After completing this work, re-vacuum, recharge the refrigerant, and finally, perform the leakage detection again.

B) If a large quantity of refrigerant spurts out, cut off the high pressure pipe to check the suction of the compressor’s low pressure pipe. If there is no suction or weak suction, it means there is not good compression and you need to replace the compressor. If suction is normal, charge the clean and warm nitrogen to the condenser pipe. If you find the returned nitrogen on the low pressure side is not sufficient, it means the system pipe is slightly clogged; please replace the clogged parts and clean the pipe.

Check the temperature of the high pressure side pipe and the compressor. You will find it is too high. Check the low pressure pipe with frost. If this is the case, it means there is too much refrigerant in the system. Please recharge with the appropriate quantity of refrigerant once more.

The system may be clogged with ice. Please replace the dry filter and clean the system with clean and warm nitrogen.

Check the electrical parts, such as the PTC starter, capacitor, overload protector, thermostat, etc. If you find the parts are malfunctioning, replace them with a new one of the same type and specification. If all of these parts are good, measure the resistance of the compressor winding. If the resistance is abnormal, you must replace the compressor. Otherwise, check if the overload protector is activated. If so, it means there is an over-large current and the compressor is malfunctioning; please replace the compressor.

Check other appliances to see if they are working.

– If there is no power supply in the neighbor’s house, the field power supply may be cut off.

– If all other appliances in the house do not work, the main fuse may be cut off.

– If only this freezer does not work, the power outlet may have a problem.

Thermostat: If the cooling thermostat is shorted or turned to the coldest point, the compressor can run. If there is a sound when turning the knob of the thermostat, the knob may be broken or not installed properly. If not, the thermostat may be broken down.

Thermal protector: Check if it is cutoff using a multi-meter. If it is cutoff, it is broken down.

PTC Starter: Check if it is cutoff or open using a multi-meter. If it is open, it is broken down.

Wiring: Check the circuit wiring according to the electrical diagram. Look for a broken point or a loose connection.

Compressor problem: Measure the winding resistance of the compressor. If abnormal, the winding is broken or burnt. Also, measure the insulation resistance with a meg-ohm meter. If the resistance is less than 1 MΩ, the winding is burnt, and the unit cannot be used for a long time.

Power Supply Voltage: If the voltage is too low (maybe lower than 175V), the compressor cannot start.

Cooling System:

– If there is no sound of refrigerant flowing and you see oil on a welding point, there is a refrigerant leakage.

– If there is no sound of refrigerant flowing and no oil on welding points, there could be an inside leakage of a cooling pipe or the pipe is blocked.

Compressor:

– If no air is discharged from the discharging mouth of the compressor, the compressor valve is broken down.

– If there is an abnormal sound inside the compressor, the compressor is broken down.

Operational Issues:

– Thermostat Setting: If the thermostat is set at a higher temperature (lower digit), set it to a lower temperature.

– Food Load: Too much food in the cooling compartment or food that is too crowded can prevent good air circulation. Remove some food.

– Hot Food: Placing high-temperature food, like hot soup, inside the freezer will let the inside temperature rise. Let food cool first.

– Door Opening: Opening the door too many times will affect the cooling effect.

– Door Gasket: Check if the door gasket sealing strip is broken or deformed. Also, check if the door is warped by food and not closing tightly.

– Unit Placement: The unit may be in direct sunshine, which prevents it from dissipating heat. The back of the unit may be too close to the wall, or there may be a heat source near the unit, both of which affect heat dissipation.

Frost: Check the thickness of the frost. If it is thicker than 5mm, it is too thick and needs defrosting.

This is caused by an abnormal action of the thermostat.

– Check if the sensor head of the thermostat is loosening or not. This can cause incorrect temperature sensing.

– The thermostat may not be of good quality or may have broken down.

This can happen if the environment is too wet, causing the relative humidity to be too high.

Insulation:

– Confirm if the insulation resistance is lower than 1 MΩ using a meg-ohm meter. If so, the insulation is not good.

– Check if the electrical parts of the unit are wet. If so, the insulation is not good.

Wiring/Grounding:

– Check if electrical parts are touching the metal enclosure or not.

– Check that the grounding lead is grounded properly.

Static Electricity:

– Check if the unit has a static electricity influence.

– Compressor: Check if the compressor has an abnormal sound or not.

– Pipes: Check if a pipe is touching another or not, which can produce resonance.

– Placement: Check if the installation ground is flat and the feet are adjusted to the proper position. If the unit is not placed evenly, it can vibrate.

Refrigerant R134a and its lubricating oil have strong water absorbability and oxidation ability. During service, you must pay more attention to the water, oxide, chloride, oil, and impurity quantities in the cooling system and control them strictly.

1) Requirement of the cooling system parts:

a) If cooling system parts (condenser, evaporator, compressor, dry filter, etc.) need to be replaced, the replaced parts should be stored charged with dry nitrogen at a pressure of 0.2~0.3Mpa. If these parts have leakage of nitrogen, they must be dried in a high-temperature chamber and have water removed before use.

b) The molecular dry desiccant inside the dry filter must be controlled strictly, guaranteed that the left water quantity is lower than 1.5WT%. Normally, after the dry filter is opened from its vacuum package, it must be welded to the pipe system within 5 minutes. In wet conditions (relative humidity > 50%), you must take measures to protect it from humidity, and the dry filter must be connected to the system pipe at once after removing it from the package.

2) Requirement of the service equipment:

① No need for recycling equipment, except for a charging machine. If the equipment is special for the R134a refrigerant system, you must mark it clearly to avoid use with other refrigerants (except welding machine, pliers, electronic balance).

② The vacuum machine and charging machine are specially used for the R134a refrigerant system.

3) Service Procedure – Special requirements:

(a) The duration from opening the compressor to the vacuuming process must be less than 10 minutes, and for other parts, not more than 12 minutes.

(b) Vacuuming duration should not be less than 20 minutes.

(c) If refrigerant leakage happens, you need to replace the compressor. Before welding, dry the cooling system with nitrogen air.

(d) If dust blockage happens in the cooling system pipe and can be blown out by the nitrogen, you do not need to replace the compressor. Otherwise, the cabinet is not useful (and the evaporator is not useful).

(e) If ice blockage happens in the system pipe, you must replace the compressor.

(f) Change the dry filter only if the system is opened.

4) Main points of service:

① The replaced compressor must be returned to the compressor manufacturer to be treated.

② The compressor cannot be tested through direct absorbing atmosphere; it will damage the compressor.

③ If the system pipe is opened for a long time or leakage happens, you can dry the system by nitrogen during service.

④ All of the welding material must be protected from wet conditions. Ensure to use as little as possible.

⑤ Check if the compressor is pressurized or not when opening.

⑦ When storing the R134a refrigerant, you must keep it sealed and not in direct contact with the atmosphere.

After completing the service, it is normally necessary to perform a test run for 1-2 days. Once it is proven to be safe and have good cooling performance, it can be moved to the customer or user. During the test run, we suggest you do the following:

1) Insulation and safety: Before plugging in, use a DC 500 meg-ohm meter to measure the insulation resistance between the live parts and the dead metal enclosure. Ensure the result is not lower than 1 meg-ohm.

2) Starting capability: The compressor should be able to start smoothly and can start or stop normally. If the unit cannot start or stop normally, you must find the root cause and delete it, then you can plug it in to let it run.

3) Cooling performance: After running for 24 hours, check that the frost on the surface of the cabinet liner is even or not, and there is no frost on the suction pipe.

4) Electrical structure and safety: After service, check all of the electrical parts. Ensure the connection terminal of the electrical parts is not loose and the grounding wire is ok.

5) Leakage checking: After running for 24 hours, check one by one the welding points by using a halogen leakage detecting device or suds. If leakage happens again, then service should be performed again.

No.	Parts name	PCS/unit
1	Compressor	1
2	Thermal protector of compressor	1
3	PTC starter	1
4	Feet of compressor	4
5	Refrigerant dry filter	1
6	Thermostat	1
7	Power cord assembly	1
8	Adjustable feet	4
9	Door gasket sealing strip	1
9	Running indicator	0
10	Power indicator	0