9
Fig. 10
1.6.4.6 Heat meter
Observe the additional pressure drop when
installing heat meters on the heating side.
The sieves inside the heat meters are easily
blocked by the dirt particles in the heating
circuit, further increasing the pressure drop.
1.6.4.7 Oxygen diffusion
Steel components, such as radiators and
pipes, can corrode if plastic underfloor heating
system pipes, which are permeable to oxygen,
are used.
The product of corrosion, i.e. rusty sludge, can
settle inside the heat pump evaporator and
can result in output loss through a reduction
of cross-section or in a heat pump shutdown
triggered by the high pressure limiter.
Therefore it is advisable to avoid open heating
systems or the installation of steel pipes in
conjunction with plastic pipes in underfloor
heating systems, which are permeable to
oxygen.
g/cm
1,130
1,120
1,110
1,100
1,090
1,080
1,070
1,060
1,050
1,040
1,030
1,020
1,010
1,000
0,990
0,980
O
= Frostsicherheit
–20 –10
0
10
20
30
°C
40
50
60
70
0 VOL-% = W
asser
40 VOL-% = (-25°C)
37 VOL-% = (-23°C)
28 VOL-% = (-15°C)
20 VOL-% = (-10°C)
44 VOL-% = (-30°C)
52 VOL-% = (-40°C)
60 VOL-% = (-50°C)
100 VOL-% = Ethylenglykol
R
3
26_03_01_0092
Frost protection
wat
er
Brine concentration
Density
U
of the ethylene glycol:water mixtures with different concentrations
1.6.4.8 Scaling
Water quality, operating conditions and the
water volume are decisive factors to the extent
of scaling. To prevent damage to valves, heat
exchanger and heating elements, check the
water condition and assess it in accordance
with VDI 2035 [or local regulations].
Note:
An awareness of hardness in
accordance with the Detergent Act [Germany]
is insufficient. Decisive for scaling is the
concentration of calcium hydrogen carbonate,
which can be supplied by your water supply
company.
1.7 Electrical connection
Notify your local power supply company of the
electrical connection.
Only qualified electricians must carry out
the installation in accordance with these
instructions.
!
Before any work, isolate the
equipment from the power supply
at the control panel.
Observe VDE 0100 [or local regulations] and the
regulations of your local power supply company.
VDE 0298-4 specifies that, in accordance
with the relevant fuse protection, the fol-
lowing cable cross-sections are to be used:
Fuse
Cable cross-section
16 A
2,5 mm²
1,5 mm² in case of two cores under
load and routing over a wall or
inside a wall mounted conduit.
25 A
6,0 mm² when routing the cable
through a wall.
4,0 mm² when routing a multi-core
cable over a wall or inside a wall
mounted conduit.
For fuse ratings, see specification
The WPF...M must be able to be separated
