Mitsubishi Electric CAHV-R450YA-HPB Service Manual page 17

[ I Read Before Servicing ]
7. Notes
To evacuate air only from the outdoor units
Apply a vacuum through the check joints on the low pressure sides.
Evacuating the system from the high-pressure side may damage the compressor.
When dry-vacuuming and recovering refrigerant, let the water circulate to keep the plate heat exchanger from freez-
ing.
HWE22020
- 8 -
GB