Weinmann & Schanz DRAIN-UNIT Manual De Instrucciones página 12

7. Place the upper insulating cover that covers the entire Drain-Unit.
N.b.: In systems with built-in regulation reconnect the cable which connects the controller to the pumps.
• Installation requirements.
The Drain-Unit station together with the collector field and an storage tank make up the drain-
back solar system. As this is a self-draining collector system the pipe-line must meet certain
requirements.
• Avoid siphons in the pipes and both in
the outflow and return.
• Collector field connection
As with the rest of the circuit, the presence of siphons in the circuit should also be avoided in the
collector field.
Collectors must be installed with the angle corresponding to the climate in the area and the
application and at a level to avoid siphons and facilitate draining.
In systems where 1-3 grill or harp type collectors are used, the bottom part of the collectors must
be connected together with fittings that do not reduce the inner outlet diameter of the solar
collectors. Thus avoiding that the fitting generates a siphon on the lower part of the collector being
connected.
• Pipes to use
The connection pipe to be used will change based on the number of solar
collectors in the system.
Number of harp-type collectors
1
2
3
• Install the pipes with a minimum
slope of 3 ° for the fluid to descend
through the pipes when the pump is
deactivated.
3º min
Pipe Cu Flexible pipe Inox
15mm
18mm
18mm
12
DN16
DN20
DN20