Wolf COB Technical Manual And Installation Instructions page 40

Directly heated DHW cylinder
Heating circuit
Low loss header
Hydraulic separation
Oil connection
40
24 Cascade operation - technical data /
control / installation information
A DHW cylinder is generally connected downstream of the system separation or via a
low loss header.
Cylinder heating is controlled via the cascade controller type KM, to which a cylinder
primary pump and the electronic cylinder sensor are connected.
The following types of connections shall be selected to ensure the heating water flow
rate through every condensing boiler is as even as possible:
1. For precise hydronic balancing, a line regulating valve can be fitted in the supply line
to every appliance.
2. Design the flow and return lines with the same length for the flow and return according
to the Tichelmann system, to ensure the pressure drop in every line is equally high.
It must not be possible for the on-site heating circuit pumps or primary pumps to
influence the function of the condensing boilers. A low loss header should therefore be
installed upstream of the heating water circuit or DHW cylinder circuit. Furthermore,
ensure that the heating water flow rate through the condensing boilers is set lower
than that through the subsequent heating circuit. The flow rate should therefore be set
upstream of the low loss header via a line regulating valve or butterfly valve.
Instead of the low loss header, a heat exchanger can be installed. If pipes are used
which are not impermeable to oxygen, this is a requirement in any case.
Each oil condensing boiler shall be provided with a suitable oil supply.
If the oil supply is only possible from one oil storage installation, this supply must be
arranged centrally via a suction unit The suction unit shall be installed as close to the
boiler cascade as possible. The oil lines shall be sized in accordance with TRÖl.
Oil storage
installation
Suction unit
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