Other Control; Backup Operation; Demand Operation; Heating Operation Prohibition - Daikin VRV EMERION REYQ-AATJA Service Manual

SiUS372201EB

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 compressor, 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 compressor, 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.
Reference
Refer to page 260 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
 Heating is disabled when outdoor air temperature is above 26°C (78.8°F).
 Heating operation is enabled when outdoor air temperature drops below 24°C (75.2°F).
Part 4 Functions and Control
Setting item
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
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.
 Forced thermostat-OFF on indoor units.
 Outdoor fan operates at step 1.
Content
Other Control
176