Bosch CA Series - Removal and Evacuation; Charging Procedures; Recovery

Installation, Operation, and Maintenance Manual
CA Series Heat Pumps - 8733851021 (2025/04) US
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18.9 Removal and Evacuation
When breaking into the refrigerant circuit to make repairs—or for any other
purpose—conventional procedures must be used. However, for flammable
refrigerants it is important that best practice be followed, since flammability is a
consideration. The following procedure must be adhered to:
1. Safely remove refrigerant following local and national regulations.
2. Evacuate.
3. Purge the circuit with inert gas (optional for A2L).
4. Evacuate (optional for A2L).
5. Continuously flush or purge with inert gas when using flame to open circuit.
6. Open the circuit.
The refrigerant charge must be recovered into the correct recovery cylinders
if venting is not allowed by local or national codes. For appliances containing
flammable refrigerants, the system must be purged with oxygen-free nitrogen to
render the appliance safe for flammable refrigerants. This process might need to
be repeated several times. Compressed air or oxygen must not be used for purging
refrigerant systems.
For appliances containing flammable refrigerants, refrigerants purging must
be achieved by breaking the vacuum in the system with oxygen-free nitrogen
and continuing to fill until the working pressure is achieved, then venting to
atmosphere, and finally pulling down to a vacuum (optional for A2L). This process
must be repeated until no refrigerant is within the system (optional for A2L). When
the final oxygen-free nitrogen charge is used, the system must be vented down to
atmospheric pressure to enable work to take place.
WARNING
Fire hazard!
The outlet for the vacuum pump must not be close to any potential ignition sources,
and ventilation must be available.
18.10 Charging Procedures
In addition to conventional charging procedures, the following requirements must
be followed.
1. Ensure that contamination of different refrigerants does not occur when
using charging equipment.
2. Ensure hoses or lines are as short as possible to minimize the amount of
refrigerant contained in them.
3. Ensure cylinders are kept in an appropriate position according to the
instructions.
4. Ensure that the refrigerating system is earthed prior to charging the system
with refrigerant.
5. Be sure to label the system when charging is complete (if not already).
6. Use extreme care not to overfill the refrigerating system.
7. Ensure the system is pressure-tested with the appropriate purging gas prior
to recharging the system.
8. Ensure the system is leak-tested on completion of charging but prior to
commissioning. A follow-up leak test must be carried out prior to leaving
the site.
18.11 Recovery
When removing refrigerant from a system, either for servicing or decommissioning,
it is recommended good practice that all refrigerants are removed safely.
Ensure the following:
1. Ensure that only appropriate refrigerant recovery cylinders are employed
when transferring refrigerant into cylinders.
2. Ensure that the correct number of cylinders for holding the total system
charge are available.
3. Ensure all cylinders to be used are designated for the recovered refrigerant
and labeled for that refrigerant (i.e., special cylinders for the recovery of
refrigerant).
4. Ensure all cylinders are complete with a pressure-relief valve and associated
shut-off valves that are all in good working order.
5. Ensure empty recovery cylinders are evacuated and, if possible, cooled
before recovery occurs.
6. Ensure the recovery equipment is in good working order.
7. Ensure set of instructions for the recovery equipment is at hand .
8. Ensure the recovery equipment is suitable for the recovery of the flammable
refrigerant. If in doubt, the manufacturer should be consulted.
9. Ensure a set of calibrated weighing scales are available and in good working
order.
10. Ensure the hoses are complete with leak-free disconnect couplings and are
in good condition.
11. Ensure the recovered refrigerant is processed according to local
legislations/regulations in the correct recovery cylinder, and the relevant
waste transfer note arranged.
12. Ensure there is no mixing of refrigerants in the recovery units and especially
not in cylinders.
13. If compressors or compressor oils are to be removed, ensure that they
have been evacuated to an acceptable level to make certain that flammable
refrigerant does not remain within the lubricant. The compressor body must
NOT be heated by an open flame or other ignition sources to accelerate this
process. When oil is drained from a system, it must be carried out safely.