Technical information

µC3 functions
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Temperature control
Two different modes (Control Menu):
1 Adjustment by water temperature at the heat exchanger inlet (sensor B5).
This control carries out a proportional type adjustment based on a set point and a proportional band
distributed over 4 stages. This is the controller default type.
It is also possible to carry out a proportional and integral adjustment. In this case, said function must
be enabled and the integration time set (CONTROL MENU).
Control sensor: B5 ((inlet water temperature to heat exchanger).
Parameters to be used:
• Set point.
• Proportional band for inlet adjustment.
• Type of adjustment (Proportional or Proportional + Integral)
• Integration time (if the Proportional + Integral adjustment has been enabled).
Control outputs: N1, N2, N6 and N7 (compressor contactors).
Description of the operation:
Temperature control depends upon the value measured by the sensor located at the water inlet to
the heat exchanger. It follows a proportional logic in which the proportional band is subdivided into
four equal stages that give way to on/off functions of the compressors. In Proportional + Integral
operation behaviour is similar, but affected by al algorithm that takes time into account (integration
time parameter).
STPM
Set point:
A = Cool
B = Heat
EWT
Exchanger inlet tem‐
perature
RBM Control band
C1,
C2,
C3, C4
Compressor stages
2 Adjustment by water temperature at the outlet of
the heat exchanger.
Thermostatic control is based on the temperature
value detected by sensor B6. Based on the set
point value (STPM) and the control base (RBM), it
defines a neutral temperature zone (NZ).
• The temperature values comprised between
the set point and the set point plus the band
(STP≤Temperature≤ STPM + RBM) do not cause the on/off function of the compressors.
• Temperature values above the set point plus the band (Temperature > STPM + RBM) cause
compressor operation.
• Temperature values below the set point (Temperature < STPM) cause compressor stoppage.
The on/off process of the compressors is controlled by a variable delay time.
Based on the time differential calculated as the delay, and in accordance with the temperature de‐
tected by sensor B6, this control will modulate the on/off process of the compressors.
If set to 0, minimum delay time at increase/decrease of the power demand, this function is disabled.
There is a different temperature differential for the cool/heat cycles (below or above...), as of which
there is an unconditional off of the devices installed to avoid excessive cool/heat cycles.
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Technical Information
1.13 Operating instructions
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