Daikin RELQ-TATJA Series, Design Manual

Page: 53 / 84

51
RELQ-TATJA / TAYDA / TAYCA EDUS371705C-D
19. Low Ambient Cooling Enhancement
RELQ72-240TATJA / TAYDA / TAYCA

RELQ-T series include a feature for Low Ambient Cooling.

The function enhances RELQ-T series as follows:
• Allows operation to −4°FDB (−20°CDB) ambient temperature in cooling mode. (Normal limit is 23°FDB (−5°CDB).)
• Operation below 23°FDB (−5°CDB) requires the addition of wind covers onto the outdoor unit.*
Application Rules:
• Total connection index of each system is limited to 50-130% when height difference is 0-194 ft. (0-50 m), 80-130% when 194-
295 ft. (50-90 m).
• All units on the system must be connected to a Branch Selector Box, Low ambient cooling is only available on indoor unit
connected to a single branch selector box. Single and Multi-port Branch Selector Boxes may be combined on one system but all
indoor units connected to a multi branch selector box will operate as standard without the low ambient cooling function.
• Function is engaged by a field setting on the outdoor unit (to enable Low Ambient Cooling) and a dip switch setting is necessary on
the Single Branch Selector Boxes BSQ-T series serving the indoor units NOT subject to Low Ambient Cooling requirements.
• During operation below 23°FDB ( − 5°CDB), the available cooling capacity decreases as follows:
14°FDB ( − 10°CDB) - Reduces to 80% of nominal.
5°FDB ( − 15°CDB) - Reduces to 65% of nominal.
− 4°FDB ( − 20°CDB) - Reduces to 60% of nominal. (Only applicable to Single-port Branch Selector Boxes)
• The operating sound level of the Single Branch Selector Boxes BSQ-T series could increase 3 dB(A) higher than maximum while
the system is operating in the Low Ambient Cooling mode. It is recommended to locate units away from zones sensitive to sound
levels.
• Allowable height difference between outdoor and indoor units (when outdoor unit is below) is limited to 130 ft. (40 m). (Normal limit
is 195 ft. (60 m).)
* Contact your local Daikin representative for wind cover specification requirements and part numbers.