Version 2.02 15.05.2007
Function of VS 3000
17
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2007 - ECKELMANN AG | BERLINER STRASSE 161 | 65205 WIESBADEN | T49(0)611 71 03-0 | FAX +49(0)611 71 03-133
Taking an example for compressor loading and unloading, the system configuration is as follows:
S
Number of base load stages: 2
S
Number of capacity stages each capacity-controlled compressor: 3
S
Number of capacity-controlled compressors: 1
Compressor loading:
Loading of compressors is illustrated in the following table for this example.
VS 3000
Relay No..
S1
S2
S3
S4
Stage
Base load stage1
Capacity stage 2
Capacity stage 3
Base load stage4
1
X
2
X
X
3
X
X
X
4
X
X
5
X
X
X
6
X
X
X
X
Loading takes place by first unloading the capacity stages of a capacity-controlled compressor. Then a non-ca-
pacity-controlled compressor is loaded. At the same time the capacity stages of the capacity-controlled com-
pressor are again loaded. Unloading of compressors is illustrated in the following table:
Compressor unloading:
VS 3000
Relay No
S1
S2
S3
S4
Stage
Base load stage 1
Capacity stage2
Capacity stage 3
Base load stage 4
1
X
X
X
X
2
X
X
X
3
X
X
4
X
X
X
5
X
X
6
X
The number of capacity stages actuated for one compressor is taken into account for compressor base load
rotation. If the system is equipped with only one multi-stage compressor or if a compressor is the variable-speed
type, limiting of compressor starts is cancelled for this compressor. Compressor starts limiting remains active for
the second and higher capacity stages as a means of preventing overlong standstill of the system.
If more than one capacity-controlled compressor or only one single-stage compressor is provided with a step
controller, limiting of compressor starts remains active for all stages. When compressor starts limiting is can-
celled for the first stage, a minimum standstill time for the first stage can be set by the
Standstill S1
xxxs para-
meter (Menu 3-3). This minimum standstill time is only shown when the system has no more than one capacity-
controlled or variable-speed compressor.