- 101 -
If the main pressure measurement remains higher than
Start Pressure
for a longer duration than
Off-
load Working Timer,
the controller stops the motor. If the main pressure measurement drops below
Start Pressure
while the motor is stopped, the motor is restarted.
Until the compressor takes the load again, the amount of time elapsed will be
Star Timer
+
Star -> Delta
Timer + Before Loading Timer + Delay Between Relays x3
.
During this period, the pressure value might be well below
Start Pressure
depending on air consumption.
However, in many systems, pressure value is required to never drop below
Start Pressure.
The unit offers 3 methods which can be configured in the
Pressure Loss Prevention Method
parameter
to eliminate this unwanted situation. The unit dynamically calculates the pressure value (
Pi, Restart
Pressure
) at which the motor will restart.
Pressure Loss Prevention Method = 0 (None)
→
No extra measures taken to prevent pressure loss.
Pi = Start Pressure
in all circumstances.
Pressure Loss Prevention Method = 1 (iteration method)
→
Each time the system takes the load, if
the pressure measurement is lower than
Start Pressure,
Pi Restart Pressure
is increased by 0.1 bar. If
the pressure measurement is higher than
Start Pressure,
Pi Restart Pressure
is decreased by 0.1 bar.
This aims to keep the reloading pressure value equal to the original
Start Pressure
.
Pressure Loss Prevention Method = 2 (curve slope method)
→
The system recalculates the
Pi
Restart Pressure
at each cycle according to the slope of the pressure loss curve after the system has
reached
Stop Pressure
.
21.6. PREVENTING PRESSURE LOSS
If the main pressure measurement at the end of Unload Timer is
higher than Start Pressure, but lower than Pi Restart Pressure,
the unit continues operating off-load.
