1. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning Topics covered in this presentation: Gauge set and refrigerant Service ports and valves Discharging, evacuating and recharging Climate Control Systems Service ClassAct SRS enabled.

2. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning Introduction Pressure tests (using the service ports), can be made to help determine faults. Faults can occur making the pressure too high or too low. The hot part of the a/c system has high pressure. The cold part of the system has low pressure. Cold Cool Hot Warm Hot Next >

3. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning 1 The cold side of an a/c system has low pressure. Is this true or false? Answer True or False. Question

4. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning Gauge Set Low pressure gauge High pressure gauge Low side valve High side valve Low pressure hose connected to low pressure service valve High pressure hose connected to high pressure service valve Service hose connected to oil supply tank Service hose connected to charging station Manifold Next > Gauge set connects to service ports.

5. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning 2 A) Black B) White C) Red D) Blue Which colour is associated with low pressure on a gauge set? Question

6. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning Gauge Dials High Pressure Gauge Low Pressure Gauge Next > High side pressure gauge displays pressure in bar (psi). Low side pressure gauge displays positive bar (psi) and negative (mm-Hg - vacuum) pressure. Note: Gauge shows 0 bar.

7. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning 3 A) psi B) vacuum C) bar D) mm Hg Which of the following is NOT a unit for the measurement of pressure? Question

8. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning Manifold Flow Control Both valves can be opened or closed for pressure checking. When the low valve is open it allows flow from the low side to the centre hose. When the high valve is open it allows flow from the high side to the centre hose. Both valves open to allow flow from both sides. Next >

9. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning Refrigerant Types Two types of refrigerant are typically used in automotives: R-12 & R-134a. R-12 is a CFC and is no longer used in new vehicles (stored in white container). R-134a is an HFC and it has replaced R-12. R-134a is normally kept in a light blue container. R-12 and R-134a containers and service port connections are different. R-134a operating pressures are higher than R-12. Next >

10. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning 4 A) R-12 B) R-134a Which refrigerant is normally kept in a light blue container? Question

11. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning Service Ports R-134a service port has a Quick Detachable fitting (QD). R-12 service port has a male imperial service fitting. Both types have Schrader valves. Service port can be connected to: Charging station. Oil refill tank. System lines. Dust caps must be fitted to the Schrader valves when they are not in use. R-12 Service Port Male thread fitting Schrader valve To charging station To system R-134a Service Port QD Fitting To system Schrader valve To charging station Next >

12. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning 5 A) Male Imperial B) Quick Detachable If you were looking at a new vehicle, which connection system would you expect to see at the a/c service port? Question

13. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning Inspection Sight Glass It is used to visually inspect the refrigerant. The inspection sight glass can be found in the accumulator (drier) or in the refrigerant line. Sight glass will show either: Clear Cloudy Bubbles (Foamy) Oil Streaked Sight glass Next >

14. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning 6 A) Liquid level B) Bubbles C) Streaks of oil D) Cloudy Which of the following would you not expect to see in an inspection sight glass? Question

15. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning The refrigerant must be discharged when the system needs to be opened. A charging station (recovery unit) is used to remove refrigerant. The charging station can connect to the gauge set or directly to the low and high service valves. Both valves will be open when recovering the refrigerant. The recovered refrigerant is recycled and can be used to recharge the system. Discharging the System The refrigerant is normally recovered slowly and controlled by the charging station. Low pressure valve open High pressure valve open Refrigerant recovery Charging station Next >

16. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning 7 A) Removing extra pressure from the system B) Removing excess refrigerant from the system C) Removing all the refrigerant from the system D) Removing the gauge set from the system What is meant by 'discharging' the a/c system Question

17. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning The vacuum created causes any moisture to boil at room temperature. The system must be evacuated when it has been discharged/opened or moisture is in the system. A vacuum pump removes any air and moisture left in the system. Both the high and low pressure valves are normally opened. Evacuating the System Low pressure valve open High pressure valve open Charging station Next >

18. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning 8 A) A vacuum pump B) A compressor C) A supply of compressed air D) A source of distilled water What is used to evacuate an a/c system? Question

19. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning The charging station is normally used to measure and refill the system with the correct amount of refrigerant. The high pressure valve is closed, and the low pressure valve is opened. The vacuum draws refrigerant into the system. The system pressures must be checked after charging. Recharging the System The amount of refrigerant to be added is measured by weight (pounds or grams), and is normally found on an A/C label under the bonnet. High pressure valve closed Low pressure valve open Charging station Next >

20. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning 9 When recharging an A/C system, both valves on the gauge set must be open fully. Is this true or false Answer True or False. Question

21. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning Possible Recharging Errors It can cause inadequate cooling, faster refrigeration cycle and low system pressures. This occurs when too much refrigerant is in the system. It produces inadequate cooling and liquid will not turn into vapour. This causes high system pressures and a constant running compressor. Moisture in the system can cause corrosion. The moisture can freeze causing erratic operation and unexpected system pressures. Undercharge Overcharge Water Moisture This occurs when there is not enough refrigerant in the system. Next >

22. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning 10 A) Undercharging B) Overcharging What causes the liquid not to turn into a vapour? Question

23. 3. Climate Control Systems Service Automotive – Heating & Air Conditioning Summary You should now be aware of: End > Gauge set and refrigerant Service ports and valves Discharging, evacuating and recharging