3 Heating engineer
Installation, Use and Maintenance Manual – GAHP-A
21
3�2 INSTALLATION
Primary and secondary circuit
▶
In many cases it is advisable to divide the hydraulic system
into two parts, primary and secondary circuit, uncoupled by
a hydraulic separator, or possibly by a tank that also acts as
inertial volume/thermal inertia.
Constant ot variable water flow
The GAHP unit may work with costant or variable water flow, re-
gardless of the ON/OFF or modulating operative mode.
System and components must be designed and installed
consistently.
Minimum water content
High thermal inertia is conducive to efficient appliance opera-
tion. Very short ON/OFF cycles are to be avoided.
▶
If necessary, provide for an inertial volume, to be suitably
sized (see design manual).
3�3 HYDRAULIC CONNECTIONS
Plumbing fittings
on the right, at the bottom, connection plate (Figure 1.1 p. 7).
▶
A (= out) 1"1/4 F - WATER OUTPUT (m = delivery to the sys-
tem);
▶
B (= in) 1"1/4 F - WATER INPUT (r = return from the system).
Hydraulic pipes, materials and features
▶
Use pipes for heating/cooling systems, protected from
weathering, insulated for thermal dispersion.
Pipe washing
▶
Before connecting the appliance, accurately clean
the water and gas piping and any other system com-
ponent, removing any residue.
Minimum components of primary plumbing circuit
▶
Always provide, near the appliance:
on water piping, both output and input (m/r)
▶
2 ANTIVIBRATION JOINTS on water fittings;
▶
2 PRESSURE GAUGES;
▶
2 ISOLATION BALL VALVES;
on the input water piping (r)
▶
1 DIRT SEPARATOR FILTER
▶
1 FLOW ADJUSTMENT VALVE, if the circulating pump is con-
stant flow;
▶
1 WATER CIRCULATION PUMP, towards the appliance;
on the output water piping (m)
▶
1 SAFETY VALVE (3 bar);
▶
1 EXPANSION TANK of the individual unit.
Figure 3�1 – Hydraulic plan
3�4 WATER CIRCULATION PUMP
The circulation pump (flow and head) must be selected and
installed based on pressure losses of plumbing/primary circuit
( comp exchange ter appliance).
For the appliance's pressure losses refer to Table 1.1 p. 16 and
Design Manual.
(1) CONSTANT FLOW circulating pump
The primary circulating pump must be obligatorily controlled
by the appliance's electronic board (S61) (see Paragraph
1.5 p. 13).
(2) VARIABLE FLOW circulating pump
For variable flow operation, use of a Wilo Stratos Para pump is
obligatory, supplied as accessory on demand, to be connected
to the Mod10 electronic board (see Paragraph 1.5 p. 13). Any
other type of pump will give constant flow.
Refer to the Design Manual for the features of the Wilo Stratos
Para pump.
3�5 ANTI-ICING FUNCTION
Active anti-icing self-protection
The appliance is equipped with an active antifreeze self-protec-
tion system to prevent icing. The anti-icing function (activated
by default) automatically starts the primary circulation pump
and, if required, the burner too, when the outside temperature
approaches zero.
Electrical and gas continuity
The active anti-icing self-protection is only effective
if the power and gas supplies are assured. Otherwise,
anti-icing liquid might be required.
3�6 ANTI-ICING LIQUID
Precautions with glycol
LEGEND
1
Anti vibration joint
2
Pressure gauge
3
Flow rate adjustment valve
4
Water filter
5
Shut off valves
6
Water pump (primary circuit)
7
Safety valve (3 bar)
8
Expansion tank
9
Hydraulic separator / inertial tank with 4
fittings
10
Water pump (secondary circuit)
