Differential Pressure Control - Daikin FTX25JVEA9 Service Manual

Si18-201
3.19

Differential Pressure Control

Outline This function sets an upper limit for the fan rotation speed according to the outside temperature
and outdoor heat exchanger temperature during cooling operation with low outside temperature.
By limiting the fan rotation, the function ensures sufficient differential pressure.
In cooling operation (outside temperature DOA ≤ 30ºC) or in heating mode oil recovery
Details
operation, this function provides an upper-limit control of the fan rotation according to the
temperature zone of the high pressure equivalent saturation temperature, as shown below.
A change of 2 Hz is made when each zone fluctuates.
The mask time is 30 seconds at the time of heating mode oil recovery operation start, and the
reset zone is set for 30 seconds when the number of operating room units changes.
When 330 rpm operation remains for 10 continuous minutes during normal cooling operation,
the thermostat is turned off.
When 330 rpm operation remains for 10 continuous minutes during heating mode oil recovery
operation, the fans are turned off.
Main Functions
DLTF4 : 40˚C
DLTF3 : 34˚C
Increasing speed
15rpm/30sec
DLTF2 : 32˚C
DLTF1 : 30˚C
System control
Reset zone
Increasing zone
No-change zone
Drooping zone
Drooping speed : 15rpm/30sec
(M1027)
137