Oil Management Safeties - Daikin EWWQ-AJYNN Service Manual

Functional Control
2.22

Oil Management Safeties

1
2.22.1 Pressure ratio alarm
2
Introduction
Function
description
3
4
5
2–78
Because the capacity control is done by oil pressure it is very important to have a minimum pressure
difference between LP and HP to be able to move the sliding vane.
When the pressure ratio is too small for a specified time, the controller will give an alarm.
pressure ratio =
Pressure ratio
■ When the unit is at 25% capacity, the unit will go into alarm when the pressure ratio is below 1.4
for a specified time.
■ When the unit is at 100% capacity, the unit will go into alarm when the pressure ratio is below 1.8
for a specified time.
■ When the unit is between 25% and 100% capacity the unit will go into alarm when the pressure
ratio is below the calculated value for a specified time.
Pressure Ratio Alarm
Min Load Setp
Max Load Setp
discharge pressure (Abs)
____________________
suction pressure (Abs)
1.8
1.4
25 % cap.
1.4
1.8
100 % cap.
Part 2 – Functional Description
ESIE07-05