Eliwell EWCM 4120, Manual, Page: 40 / 75

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By setting parameter Fn25 =-1 it is also possible to define that the fan is absent (no condensation) and the relative
regulator will not be actuated. If a probe is configured as a temperature probe or outlet pressure probe, the
condensation regulation is proportional or Neutral Zone (NZ). In the case of pressure regulation, the AI4 probe must
be used (low resolution probe). If no outlet probe has been configured, the fans will be piloted by default depending
on the operating mode (Heat or Cool). In local or remote OFF the fans are switched off.
The fan can be directly connected to the controller via the Triac output or relay or indirectly connected via an
external module (connected to controller via a PWM or analogue output):
• Direct Triac TC output
• Indirect “PWM” output AO1, AO2 (needs external module for piloting fan).
• Indirect 4..20mA / 0..20mA / 0..10Vcc output AO3 (needs external module for piloting fan).
• Relay outputs for piloting digital fans
• Digital Output DO5 (Open Collector) using an external relay.
One or more digital inputs can be configured as fan thermal switch:
• Digital inputs DI1…DI7.
• Analogue inputs AI3 …AI4 if configured as digital inputs.
It is possible to configure a relay as fan INVERTER enabling output.
INVERTER COMPRESSOR CONTROL
Pick-up
Each time the fan starts, the exchanger fan is supplied at the maximum voltage level, hence the fan runs at the
speed established by parameter Fn23 (max. pick-up speed) for a time equal to the value set via parameter Fn13
(pick-up time). After this time, the fan will continue at the speed set by the regulator. However if the regulator
wants to turn the ventilation off during the pick-up time, the fan will be switched off. The pick-up time will be
reloaded at the next start.
The speed specified by parameter Fn23 may be reached in one of two ways depending on the value of parameter
Fn12 (mode for reaching maximum pick-up speed):