Fujitsu Airstage J-II, Service Manual

Page: 46 / 209

3-2 MASTER CONTROL
03-02
3-2-1 Operation Mode Control
(2) Cool, Dry and Heat Mode
Indoor fan motor Operates according to
the AIR FLOW-MODE
setting. See the fan control
page.
Cool Dry
Drain pump
Turns ON-OFF by the drain pump control function
Electrical
expansion valve Pulse controlled by
the temperature differ-
ence calculation and
frost prevent fuction
Each operation mode is controlled as below.
(1) Stop mode
Indoor fan motor : OFF
Electric expansion valve
Drain pump
: Stop pulse
: Turns ON-OFF by the drain pump control function
Operates according to
the AIR FLOW-MODE
setting, and besides
cold air prevention
operation
Pulse controlled by
the temperature dif-
ference calculation
and frost prevent
function
Heat
Pulse controlled by
the temperature dif-
ference.
(
3) Priority mode
The purpose of the priority mode is to restrict operation commands (heating, cooling, dry) from the
connected indoor units. There are 3 priority modes of Neutral, Cooling Priority, and Heating Priority.
The operation modes restricted by each of these modes are as follows:
Priority mode
Neutral
Cooling priority
Heating priority
Restricted operation mode
No restrictions
Heating
Cooling, dry
Neutral
Cooling priority Heating priority
Cooling priority Heating priority
1. Priority mode decision methods
Method 1. (Default value)
The initial priority mode is made Neutral and is shifted to Cooling Priority when cooling and to Heating
Priority when heating depending on which operation mode (cooling, heating) was input first.
After shifting to Cooling Priority or Heating Priority, the priority mode shifts to Neutral only when there
was a Stop input from all the indoor units.
Method 2. (Management by outdoor unit)
Operation mode management is made "Management by outdoor unit" by outdoor unit PUSH-SW
(field setting).
The priority mode shifts to Cooling Priority or Heating Priority in accordance with input from the outdoor
unit regardless of the current mode.