EVCO c-pro micro SAVE - Manual (Page 37)

C-PRO MICRO SAVE APPLICATION MANUAL
Page 37
6.6.1.5 Fans status
Each of the two fans can be in the following working states:
1. OFF: the fan is OFF.
2. ON V1: the fan is ON at speed 1.
3. ON V2: the fan is ON at speed 2.
4. ON V3: the fan is ON at speed 3.
5. Switch-ON stand-by: the fan is to be switched-on. Timing is in progress, e.g. stand-by due to
pre-start of the outside air damper. The status shows the switch-on stand-by for each of the
individual speeds.
6. Switch-OFF stand-by: the fan is to be switched-off. Timing is in progress, e.g. in the case of
post-ventilation.
7. Alarm: the fan is in alarm conditions due to thermal overload.
Reaching of the individual speed in switch-ON can be delayed via the parameter PF06. If PF06=0
switch-ON/OFF is immediate.
6.6.1.6 Fans running hours
Each fan has an associated variable that counts the number of running hours (Supply fan parameter
PM02, Return fan parameter PM03). The running hours can be zeroed by resetting the relevant
parameter.
If the running hours set in the PM01 parameter are exceeded, an alarm is given indicating fan
running hours exceeded (alarms AL09, AL10).
6.6.2 Recovery heat exchanger anti-freeze protection
A probe measures the temperature T of the exhaust air after the recovery heat exchanger on the
extraction circuit. The critical defrosting temperature Tg (can be set by parameter PF07) is fixed by
default at 0 °C. Considering the risk of frost in the recovery heat exchanger when T ≤ Tg it is
necessary to take some action for protecting the exchanger when this temperature level is reached.
To use this function the PG06 parameter must be enabled (by default it is always enabled).
There are two possible strategies depending on the presence of the by-pass damper (stated by the
state of the dedicated digital input which polarity is determined by the PH55 parameter).
The two antifreeze strategies are described in the following paragraphs.
Note: If the anti-freeze temperature probe is in error conditions, this regulation is not enabled and the fans are regulated
exclusively on the basis of the PF01 parameter.
6.6.2.1 Unit without By-pass damper (digital contact not active)
In this case the action taken for anti-freeze purpose is decreasing the fan speeds with a neutral zone
control.
When T ≤ Tg, the outlet fan speed will decrease progressively (V3-V2-V1) until stopping (V0). If
this condition occurs and remains for a time ∆t (time set by parameter PF09) the speed reduction
takes place, every ∆t there is a further decrease until the supply fan switches OFF.
Fan speed decrease every ∆ t
Neutral
Zone
Normal Working
Tg Tg + Tdiff T. Anti-freeze