LG PRHR Series Installation Manual page 10

Installation
WARNING
If you want to use a PRHR030 for 2 rooms HR unit after closing the 3rd pipes, set the dip switch for 2 rooms HR unit.
If you want to use a PRHR040 for 3 rooms HR unit after closing the 4th pipes, set the dip switch for 3 rooms HR unit.
If you want to use a PRHR040 for 2 rooms HR unit after closing the 3rd and 4th pipes, set the dip switch for 2 rooms HR unit.
The unused port must be closed with a copper cap, not with a plastic cap.
2. SW05M (Rotary S/W for addressing HR unit)
Must be set to '0' when installing only one HR unit.
When installing multiple HR units, address the HR units with sequentially increasing numbers starting from '0'.
Ex) Installation of 3 HR units
10 HR Unit
3 4
3 4
1 2
3 4
3 4
1 2
3 4
3 4
1 2