Cascade Operation - Wolf MGK-2-390 Installation Instructions Manual

Cascade module setting
Pump speed setting
Setting the eBUS address in
cascade mode
50

27. Cascade operation

The standard settings of the Wolf cascade module can lead to cycling in very
sluggish heating systems.
For optimum cascade operation, we therefore recommend the following settings:
If the circulation and feed pump (ZHP) are controlled by the Wolf boiler control unit
during operation with low loss header, the flow rates of the primary and secondary
circuits may differ from each other.
If the secondary flow rate is much greater than the primary flow rate, this can lead to
cycling of the boiler.
In this case, we recommend significantly increasing the minimum pump speed.
To do this, increase parameter HG16 in 20 % steps.
The higher the set header temperature, the higher the pump speed that must be
selected for the feed pump. Set header temperatures of more than 75 °C should be
avoided if possible.
In cascade operation, the condensate pump must be connected externally with
Caution
constant voltage, as the condensate flowing back cannot be discharged otherwise
when the boiler is switched off (e.g. for boiler maintenance).
The eBUS address is set in the contractor menu HG10 on the AM display module or
the BM2 programming module.
Boiler in cascade mode
*Factory setting (individual boiler without cascade mode)
Parameter
KM10
KM11
Boiler 1
Boiler 2
Boiler 3
Boiler 4
Setting
20
500
eBUS address
1*
2
3
4
3063772_201507