Mitsubishi Electric CITY MULTI PURY-HP72TNU-A Data Book page 124

13. OUTDOOR INSTALLATION
200mm [7-7/8 in.]
max.
13-3-7. Twinning on the outdoor unit side
See the following drawing for connecting the pipes between the outdoor units.
<In case of 2units combination>
MEES19K180
Outdoor unit 1
On-site piping
Outdoor unit 2
twinning pipe
Twining Kit
Hyper Heating Inverter R2-Series
To BC controller
122