Daikin VRV RXYQ72-384XAYCA, Service Manual

Page: 111 / 419

SiUS342004EB Other Control
Part 4 Functions and Control 104
Reference
8. Other Control
8.1 Backup Operation
If any of the compressors goes wrong, disable the relevant compressor or the relevant outdoor unit
from operating, and then conduct emergency operation only with operational compressors or
outdoor units.
Emergency operation with remote controller reset and emergency operation with outdoor unit
PCB setting are available.
(1) Emergency operation with remote controller reset
[Operating method]
Reset the remote controller. (Press the ON/OFF button for 4 seconds or more.)
[Details of operation]
Disable the defective outdoor unit from operating temporarily, and then only operate other outdoor
units. (On the system with 1 outdoor unit, this emergency operation is not available.)
(2) Emergency operation with outdoor unit PCB setting
[Setting method]
Make setting of the unit, "the operation of which is to be disabled", in field setting mode (setting
mode 2).
[Details of operation]
Disable the defective outdoor unit from operating, and then only operate other outdoor units.
(On the system with 1 outdoor unit, this emergency operation is not available.)
8.2 Demand Operation
In order to limit the power consumption, the capacity of outdoor unit is forcibly reduced by using
Demand 1 Setting or Demand 2 Setting.
To operate the unit with this mode, additional setting of Continuous Demand Setting or external
input by external control adaptor for outdoor unit is required.
Refer to page 187 for the power consumption limitation details.
8.3 Heating Operation Prohibition

When outdoor air temperature is too high, outdoor unit cannot operate in heating mode
because:

Low pressure sensor can give pressure value above upper limit of sensor: error JC .

Mechanical internal load on compressor increases.

Low compression ratio can result in insufficient compressor internal oil lubrication.

Heating is disabled when outdoor air temperature is above 26°C (78.8°F).

Forced thermostat-OFF on indoor units.

Outdoor fan operates at “step 1”.

Heating operation is enabled when outdoor air temperature drops below 24°C (75.2°F).
Applicable model
Operating method
(1) Emergency operation with
remote controller reset
(Auto backup operation)
(2) Emergency operation with
outdoor unit PCB setting
(Manual backup operation)
RXYQ192-384XA
RXYQ192-384XB
Backup operation by outdoor unit Backup operation by outdoor unit
Setting item Content
Demand 1 (step 1) The compressor operates at the power of 60-95% or less of the rating.
Demand 2 (step 2) The compressor operates at the power of 40-55% or less of the rating.
Demand 3 Forced thermostat OFF