NAVAC NR7 Recovery Unit User Manual

Table of Contents

General Safety

Information Usage: To extend the service life of the recovery unit, please read the manual carefully before use to fully understand safety, specifications, and operating procedures.

• Verify the received product matches your order.
• Check for any damage incurred during transport.
• Contact your local distributor if you encounter any issues.
• Read the manual carefully and operate the unit according to the product's operating procedures.

! Warning: This mark indicates procedures that must be strictly observed to prevent risks to people.

Note: This mark indicates procedures that must be strictly followed to avoid damage or destruction of the unit.

General Safety Precautions:

• Only authorized rechargeable refrigerant cylinders may be used. The pressure limiting device setting should not be less than 45 bar (653 psi).
• Do not overfill the recovery tank; keep it at a maximum of 80% capacity to ensure sufficient space for liquid expansion. Overfilling can lead to violent explosion.
• Always wear safety glasses and protective gloves when working with refrigerants to protect your skin and eyes from injury caused by refrigerant gases or liquids.
• Do not use this equipment near flammable liquids or gasoline.
• A digital scale is required to prevent overfilling.
• Ensure the work area is well-ventilated.

Notes on Usage:

• Ensure the unit operates under the correct power supply.
• When using an extension cord, it must be a minimum of 14 AWG and not exceed 25 feet in length to prevent voltage drop and compressor damage.
• The unit's inlet pressure should not exceed 26 bar (377.0 psi).
• The unit must be placed horizontally; otherwise, it may cause unexpected vibrations, noise, or abrasion.
• Do not expose the unit to prolonged sunlight or rain.
• The unit's ventilation opening must not be obstructed.
• If the overload protector trips, reset it after 5 minutes.
• During the auto-purge operation, slowly turn the knob to "PURGE" to ensure the inlet pressure is below 5 bar (72.5 psi).
• If a slugging occurs during recovery, slowly turn the knob to the "SLOW" position and do not let the reading pressure drop to zero.
• When selecting the fast mode to start work, monitor the outlet pressure. If the outlet pressure rapidly increases to 27 bar (391.6 psi), slowly switch to slow mode and monitor that the outlet pressure does not exceed 35 bar (507.6 psi).
• The equipment is intended for servicing air conditioning and refrigeration systems containing less than 200 lbs of high-pressure refrigerant.
• The tank and hose used must comply with local regulations.

User Manual

1. Connect the power supply. The toggle switch is in the "-" position, and the indicator light is on for 2 seconds then off. Press and hold the "<0xF0><0x9F><0x94><0x8B>" button for more than 0.2 seconds and release to start the unit. After an interval of more than 0.5s, press and hold the "<0xF0><0x9F><0x94><0x8B>" button for more than 0.2 seconds and release to shut down the unit. After an interval of more than 2 seconds, press the "<0xF0><0x9F><0x94><0x8B>" button to start the unit.
2. Do not mix different refrigerants in the same tank, as they cannot be separated or reused.
3. Before recovering refrigerant, the tank must reach a vacuum level of -29.6 inches of mercury to purge non-condensable gases. Each tank is filled with nitrogen at the factory; therefore, evacuate the nitrogen before first use.
4. The knob must be in the "CLOSED" position before operation. All valves must be closed, and inlet/outlet connections should be protected with dust caps when the unit is not in operation. Air/moisture are detrimental to recovery results and will shorten the unit's lifespan.
5. A desiccant filter must always be used and replaced regularly. Each type of refrigerant requires its own filter. To ensure proper unit performance, use a specified high-quality desiccant filter. A high-quality desiccant filter will help protect the machine.
6. Special attention is required when recovering from the system, and two desiccant filters are necessary.
7. The unit is equipped with an internal high-pressure protector. If the system pressure exceeds the rated cutoff pressure (refer to specifications), the compressor will automatically shut down, and "HP CUTOFF" will be displayed. To restart the compressor, reduce the internal pressure (outlet gauge shows pressure below 35 bar/507.6 PSI), and after the HP CUTOFF flashes, press the "START" button to restart the compressor. When the high-pressure protection is triggered, determine the cause and rectify it before restarting the unit.
• The refrigerant tank inlet valve is closed - opening the valve will help resolve the issue.
• The connection hose between the recovery unit and the refrigerant tank is blocked - close all valves and replace the connection hose.
• The refrigerant tank temperature is too high, causing high pressure - cool the tank.
8. The unit is equipped with an O.F.P. port and can be connected to a cylinder with a complete liquid shut-off using the O.F.P. cable. When the O.F.P. cable is not plugged in, the unit automatically blocks the O.F.P. function.
9. When recovering a large amount of liquid refrigerant, the "push-pull" mode is recommended.
10. To ensure no refrigerant remains in the equipment after recovery, carefully read the "self-purge procedure" in this manual. Residual liquid refrigerant in the condenser can expand and damage components.
11. The low-pressure gauge on this equipment indicates the pressure at the compressor inlet within the recovery machine; the high-pressure gauge indicates the pressure at the outlet.
12. After using the equipment, turn the knob to the "CLOSED" position.

Specifications

Flow Rate (lb/min)

Flow Rate vs. Inlet Pressure

Graph showing the relationship between vapor flow rate and inlet pressure for the NR7 unit.

Note: Vapor flow rate is proportional to inlet pressure.

Control Panel Introduction

Start-up Switch: Start/stop the unit. Press and hold for 0.3 seconds to start, press again after 2 seconds to stop.

• Overload: Overload warning indicator.
• O.F.P. CUTOFF: Illuminates when the recovery cylinder is 80% full or the O.F.P. cable is short-circuited. The machine will stop operating.
• HP CUTOFF: Illuminates when the high-pressure switch is activated above 560 psi.
• CLOSED: Inlet valve closed.
• RECOVER: Inlet valve partially open.
• FAST: Inlet valve fully open.
• PURGE: Inlet valve closed, outlet valve open, allowing refrigerant in the equipment to be recovered.

Parts Diagram

Exploded view of the NAVAC NR7 recovery unit, showing all components with corresponding numbers.

List of parts:

• 1. Left Side Panel
• 2. Start Switch
• 3. Toggle Switch
• 4. O.F.P. Cable
• 5. Power Supply
• 6. Condenser
• 7. Upper Panel
• 8. Rear Panel
• 9. Inlet Hose
• 10. Outlet Hose
• 11. Compressor
• 12. Motor
• 13. Fan Blade Cover
• 14. Fan Blade
• 15. Right Side Panel
• 16. Button
• 17. Hose
• 18. Control Assembly
• 19. Motor Control Board
• 20. Base
• 21. Inlet Gauge
• 22. Outlet Gauge
• 23. Indicator Board
• 24. Front Panel

Electrical Diagram

Schematic of the electrical connections for the NAVAC NR7 recovery unit, showing components like MCB, motor, switches, and indicators.

Component Key:

• M: Motor
• MCB: Motor Control Board
• XS: Cable
• DCB: Indicator Board
• LS: Low Pressure Sensor
• OFP: Overfill Protector
• TP: Temperature Protector
• HP: High Pressure Switch
• TS: Temperature Sensor
• PS: Start/Stop Switch
• RS: Toggle Switch
• L1: High Pressure Alarm Indicator
• L2: Full Liquid Alarm Indicator
• L3: Overload Alarm Indicator

Operating Instructions

Step A: Hose Evacuation

Follow the diagram for proper hose connection.

1. Ensure system and recovery tank vapor and liquid valves are closed.
2. Open the collector gauge vapor and liquid valves.
3. Loosen the refrigerant tank connection hoses.
4. Open the hose control valve.
5. Connect the power and turn on the unit.
6. Turn the knob to "FAST".
7. Press the "<0xF0><0x9F><0x94><0x8B>" button to start the unit and begin pumping air from the hose.
8. Observe the low-pressure gauge; the needle should be between "-76 cmHg to 0" for 30s.
9. Turn the knob to "CLOSED", then slowly to "PURGE" to remove remaining air.
10. Observe the low-pressure gauge; the needle should be between "-76 cmHg to 0" for 30s.
11. Connect the refrigerant hose to the tank.
12. Turn the knob to "CLOSED".
13. Press the "<0xF0><0x9F><0x94><0x8B>" button to stop the recovery machine.

Step B: Recovery Mode

Note: An electric scale is necessary to monitor the recovery process and prevent overfilling.

Connect hoses firmly as shown in the diagram.

1. Open the system's vapor and liquid valves.
2. Open the collector gauge's vapor valve.
3. Turn the knob to "FAST".
4. Slightly loosen the tank connection hose to vent air, then immediately tighten the connection.
5. Close the collector gauge's vapor valve.
6. Open the corresponding tank connection (vapor recovery to liquid port, liquid recovery to vapor port).
7. Press the "<0xF0><0x9F><0x94><0x8B>" switch to start the unit.
8. If recovering liquid refrigerant, open the collector gauge's liquid valve.
9. If recovering vapor refrigerant, open the collector gauge's vapor valve.
10. Run until the desired vacuum level is reached. Then, turn the knob to "PURGE" to start the purge process.

Note: If slugging occurs during recovery, slowly turn the knob to "SLOW" and monitor the low-pressure gauge until slugging stops. Do not let the reading pressure drop to zero, as the inlet port will not pump once pressure reaches zero.

If starting is difficult, turn the knob to "CLOSED" when handling liquid, turn to "PURGE" when handling vapor, then press "<0xF0><0x9F><0x94><0x8B>" to restart the machine and turn it to the required position.

Step C: PURGE Mode

Note: The unit must be purged after each use. Residual refrigerant can expand, damage components, and pollute the environment.

1. Once the desired vacuum level is reached, turn the knob to "PURGE" and begin purging.
2. Observe the low-pressure gauge; let it run until the desired vacuum level is achieved.
3. Press the "<0xF0><0x9F><0x94><0x8B>" switch to stop the recovery machine.
4. Close the tank's vapor valve.
5. Disconnect the outlet hoses. (Note: residual refrigerant remains in the hose)
6. Turn the knob to "CLOSED".
7. Turn off the power switch. Disconnect the power cord.
8. Disconnect all hoses.

Liquid Push-Pull Mode

Note: An electric scale is necessary to control the recovery process and prevent overfilling.

Connect hoses firmly as shown in the diagram. Ensure all valves are closed.

First, evacuate air from the recovery machine: loosen the outlet hose, turn on the recovery machine, turn the knob to "FAST", then turn the knob to "PURGE", turn off the recovery machine.

1. Open the system's vapor valve, rapidly release some refrigerant, and tighten the outlet hose.
2. Open the system's liquid valve, slightly loosen the liquid hose connected to the tank, rapidly release some refrigerant, and retighten it.
3. Open the tank's vapor and liquid valves.
4. Turn the knob to "FAST".
5. Press the "<0xF0><0x9F><0x94><0x8B>" button to start the recovery machine.
6. Once liquid is recovered, slowly turn the knob to "PURGE" to start purging.
7. Close the system's vapor and liquid valves.
8. Close the tank's vapor and liquid valves.
9. Disconnect and reconnect all hoses for Step B - Recovery Mode.
10. Turn the knob to "CLOSED".

Troubleshooting

Correct Disposal of this Product:

This marking indicates that this product should not be disposed of with other household wastes. To prevent possible harm to the environment or human health from uncontrolled waste disposal, recycle it responsibly to promote the sustainable reuse of material resources. To return your used device, please use the return and collection systems or contact the retailer where the product was purchased. They can take this product for environmentally safe recycling.