1. Limits and objectives
This technical manual is intended for technical services performing support for air compression compressor units. The purpose of this manual is to ensure the effective execution of work involving checking the refrigerant charge, testing the discharge valve and cleaning the heat exchanger in order to maintain optimal system operation. The technician must perform these tasks during periodic technical maintenance, as well as when an increase in moisture in the air or a decrease in system efficiency is detected.
2. Safety and Conditions
Warning: Access denied to equipment that is not disconnected and locked out.Before starting any work, perform the lockout/tagout (LOTO) process to eliminate the risk of contact with energy or moving parts. Use personal protective equipment (PPE): gloves, goggles, hearing protection, hard hats, as well as clothing that protects against liquids and refrigerants.
Do not perform work at high pressure or temperature in the system. Before starting work, disconnect the electrical supply and open the ventilation openings for air release.
3. Required Tools and Materials
| Tool Name | Specification | Quantity |
|---|---|---|
| Torque wrench | Range 10-60 Nm | 1 |
| Multimeter | Range 0-250 V, 0-10 A, 0-500 MOhm | 1 |
| Laser Aluminum Alierator | Accuracy ±0.02 mm | 1 |
| Pressure Gauge | Range 0-10 bar | 1 |
| Set of keys | Size 6–24 mm | 1 |
| Thermometer | Range -20 to 120 °C | 1 |
| Air dryer | Pump, fine filters | 1 |
| Cleaning tools | Tweezers, paper for drying, cleaning fluid | 1 |
4. Pre-maintenance inspection checklist
| Item | Check | Acceptance/Rejection Criteria | Notes |
|---|---|---|---|
| 1 | Power supply disconnection check | Electricity supply must be disconnected | Apply the LOTO method |
| 2 | Pressure check in the system | The pressure must be less than 0.5 bar | Open ventilation openings |
| 3 | Check for absence of refrigerant | Absence of noticeable seals | Use the pressure gauge |
| 4 | Valve discharge check | The valve must be open | Use the pressure gauge |
| 5 | Inspection of the heat exchanger status | Absence of deposits or contamination | Use tweezers |
5. Step-by-step procedure
Disconnection of power supply and checking the pressure in the system
Perform the LOTO procedure and disconnect the power supply. Open the ventilation openings to release air and reduce the pressure to less than 0.5 bar.
Error: Failure to disconnect the power supply may result in injury.
Checking the refrigerant level using a manometer
Install the pressure gauge at the inlet and outlet of the system. Raise the temperature to 30 °C to ensure stable readings. The refrigerant level should be within the range of 1.5–2.5 bar.
Error: incorrect installation of the pressure gauge may lead to incorrect measurement.
Testing the exhaust valve using a manometer
Open the vent valve and measure the pressure at the outlet. After closing the valve, the pressure must drop to 0.1 bar within 10 seconds.
Error: absence of valve opening may lead to moisture accumulation.
Cleaning the heat exchanger using a dryer and paper
Disconnect the heat exchanger and use a dryer to remove moisture. Use paper to remove deposits. Check that no moisture remains.
Error: improper cleaning may lead to reduced efficiency.
Installation of heat exchanger and removal of dryer
Install the heat exchanger in place and secure it. Turn off the dryer and check that no moisture remains.
Error: Incorrect installation may cause damage.
Pressure and Temperature Check using a pressure gauge and thermometer
Measure the pressure at the inlet and outlet. The temperature should be within the range of 30–40 °C. Record the readings.
Error: incorrect verification may lead to incorrect measurement.
Restoration of power supply and system check
Turn on the power supply, perform the work according to the instruction. Measure the pressure and temperature again to ensure stability.
Error: absence of verification may lead to malfunction.
6. Post-maintenance inspection checklist
| Test | Expected result | Actual Result | Pass/Fail |
|---|---|---|---|
| 1 | System pressure | 0.5-1.0 bar | |
| 2 | Outlet temperature | 30-40 °C | |
| 3 | Outlet valve | Closed | |
| 4 | Moisture in the system | Missing | |
| 5 | Electrical Supply | Inclusion |
7. Technical Assistance
| Symptom | Possible cause | Restorative effect |
|---|---|---|
| Increase in air humidity | Incorrect refrigerant measurement | Check the refrigerant level |
| Reduction of efficiency | Contaminated heat exchanger | Clean the heat exchanger |
| Improper operation of the vent valve | Valve mounting | Check and secure the valve |
| System malfunctions | Incorrect pressure measurement | Check the pressure gauge |
| Overheating of the system | Blocked heat exchanger | Clean the heat exchanger |
8. Recommended Maintenance Schedule
| Task | Frequency | Estimated duration | Skill Level |
|---|---|---|---|
| Refrigerant Check | Monthly | 30 min | Average |
| Valve discharge test | Monthly | 15 min | Average |
| Heat exchanger cleaning | Quarter | 45 min | High |
| Pressure and Temperature Check | Monthly | 20 min | Average |
| General inspection | Annual | 2 years | High |
9. Special Components
| Component Description | Typical specifications | Category UNITEC-D |
|---|---|---|
| Pressure gauge | Range 0–10 bar | Category 313 |
| Outlet valve | Stainless steel | Category 314 |
| Air dryer | Pump, fine filters | Category 315 |
| Heat Exchanger | Stainless steel | Category 316 |
| Refrigerant | Type R-134a | Category 317 |
10. References
These works must be carried out in accordance with the standards DSTU, EN, ISO, as well as in accordance with the manufacturer's documentation. All works must be carried out using CE, UkrSEPRO certification.
Additional recommendations
This is a practical guide for technical services performing maintenance on air compression compressor units. Carrying out these tasks will ensure the efficient operation of the system and increase its service life.
