34
Digital compressor control
The regulator calculates the number of refrigeration resources required by the system through a policy of assigning
resources selectable with parameter CP10 (Activation policy).
Activating or deactivating power steps must respect the activation and release times for resources CP15 and CP16
which are loaded on activation/release.
In alarm conditions, (e.g. due to the intervention of a compressor block) any reduction in power required is
calculated immediately. however, the power make-up must always keep to the time intervals described above,
particularly the activation time of the CP15 resources.
Proportional band: this occours if bit0 of parameter ST04 equals 0 (this occours for St04=0 and St04=2).
The operation depends on the parameter ST02: Cooling mode if St02=1 and Heating mode if St02=0.
The digital compressor control is stepped as a function of the inlet probe value.
The regulator activates a certain number of resources (power steps) to reach the Set point configured. The number of
resources required is linked to the difference between the value measured by the inlet probe and the set point;
Naturally, the greater this difference, the greater the number of resources required to reach the setpoint. The
temperature /pressure interval between activation of one power step and the next depends on the proportional band
and the number of resources present.
In the event of a regulation probe error, the number of active power steps is calculated as a percentage set at
parameter CP21 of the complete number of steps.
The following is an example of regulation with lateral set point (St01=1). In the case of central set point (St01=0) the
proportional band is deemed to be centred in the set point.
To Next Page
Loading...
