AIR CONDITIONING

C7000 Advanced
A5
Control
Valves
G-valve
The pressure setpoint is entered in the
2nd line and relates to the refrigerant condensation
pressure in the condenser. ➊
The pre-start serves to provide a sufficient
flow for the heat absorbing medium and
to pre-cool the heat absorbing medium.
When compressor operation is requested,
the G-valve opens and the compressor
start is delayed by the pre-start time. ➋
The pre-open value is the G-valve opening
which should be obtained during the prestart
time. ➌
To avoid a constant discrepancy from
the set value there are three parameters,
which imitate the behaviour of an integral
control.
The control factor ➍ is the decisive value,
by which the extent of the control correction
is adjusted in the way of calculating
the actuating variable after the lapse of
an adjustable control cycle ➎ (0-10 sec)
according to the following formula:
S new = S old - f • (set value - actual value)
S: actuating variable - here valve opening
f: control factor
Set value: condensation pressure
To avoid a drastical change you can adjust
a maximum control correction ➏ (0
- ±10%). This control correction relates to
the old actuating variable in each cycle.
C7000 PT2
➊
➋
➌
➍
➎
b5
Cool/G-valve □ 27
→Set 18,0 bar
+Pre-start 5 s
+Pre-open 50 %
+I-factor 10 %
+D-factor 20 %
On 0,0 %
The surrounded numbers refer to the corresponding
passages in the descriptive text.
The operation status of the G-valve is displayed
in the last line.
C7000
The corresponding commands:
➊ gvalve press 18,4
➋ gvalve pretime 15
➌ gvalve preopen 40
➍ gvalve fact 2
➎ gvalve concyc 5
➏ gvalve maxc 5
Times are entered in seconds.
The surrounded numbers refer to the corresponding
passages in the descriptive text.
E/1006/57/49