ECKELMANN VS 3000 User Manual

Version 2.02 15.05.2007
Function of VS 3000
13
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E 2007 - ECKELMANN AG | BERLINER STRASSE 161 | 65205 WIESBADEN | TELEFON +49(0)611 71 03-0 | FAX +49(0)611 71 03-133
ZNR. 51203 64 530 E0
t
0 min
t
0 max
Room temperature t [°C]
Low-pressure control
r
-35
-30
-25
-20
-15
-10
-5
-0
0 5 10 15 20 25 30 35
t
r max
t
r min
t
0
Suction pressure
Temperatures t
0_max
,t
0_min
,t
r_min
and t
r_max
can be set as parameters. Additionally, allowance can be made for
the air humidity via an analog input. The pressure setpoint for actual control is determined from a conversion
table s tored in the program. Provision is currently made for the following refrigerants w hen converting t
0
to the
corresponding pressure:
R22, R502, R134a, R402A, R404A, R717, R1270, R507, R407c, R410a, R290 R744 (no transcritical operation)
3.6.2 Demand-dependent calculation of setpoint
This function is only available in conjunction with case/coldroom controllers that deliver load-level data
(valve opening), e.g. UA 300 E.
In order to ensure optimum operation of a compressor pack and associate refrigeration points at minimum oper-
ating cost it is appropriate for the low pressure controlled by the compressor pack to be set as a function of re-
frigeration load at the refrigeration points.
The opening of the expansion valves at the refrigeration points lends itself as a reference input for this purpose.
With a load level equal to a definable maximum at a minimum of one refrigeration point served by the com-
pressor pack, it may be assumed that the temperature cannot be maintained reliably with the existing low pres-
sure at this/these refrigeration point/s. In this instance low pressure is decreased so as to be able t
0
supply suffi-
cient refrigeration capacity.
Conversely, when the load level at all refrigeration points served by the compressor pack is less than a defin-
able minimum, it may be assumed that the refrigeration capacity supplied by the pack is more than sufficient. In
this instance the low pressure is increased in the interests of energy-efficient operation of the plant. The t
0
set-
point should not be shifted up when superheat control is active on a transmitting case/coldroom controller. In this
instance the defined t
0
setpoint is retained or shifted down by increasing the valve opening.

ECKELMANN VS 3000 Specifications

General

Brand	ECKELMANN
Model	VS 3000
Category	Controller
Language	English