10
Before commissioning
Filling the system
The system is filled at the customer-provided filling
and draining connections.
Anti-freeze protection for the medium
If a water-glycol mixture is used, it is to be pre-
mixed before being put in the system. The desired
concentration is then to be checked.
Unit preliminary pressure for the medium
The preliminary pressure of the medium (without
operation of the circulation pump) varies within the
system. From the highest point, the pressure
increases by approx.10 kPa (0.1 bar) per metre dif-
ference in altitude (geodetic altitude). The value
measured at the highest point is identified as the
non-circulating pressure.
The position of the unit in the system is decisive in
the calculation of the unit's preliminary pressure
(pressure of the manometer on the unit installed by
the customer). The pressure must be set to at least
70 kPa (0.7 bar).
n
If the unit is positioned at the
lowest
point in
the system, the unit preliminary pressure
(=standstill pgeodetic system altitude)
must be set to
at least 70 kPa (0.7 bar) + 10
kPa (0.1 bar) x geodetic system altitude
.
n
If the unit is positioned at the
highest
point in
the system, the unit preliminary pressure
(=non-circulating pressure) must be set to
at
least 70 kPa (0.7 bar)
. Please note that the
system pressure at the lowest point is
increased
by the geodetic system altitude!
A
A
B
C
Fig. 27: Unit preliminary pressure
A: Unit preliminary pressure
B: Geodetic system altitude
C: Non-circulating pressure
Bleeding the system
n
Air may still be in the pipe lines after the leak
testing. This is carried during operation of the
circulation pump to the automatic bleeding
valves or to the cold water drain. It is neces-
sary to bleed again here.
n
Also bleed the pump if necessary.
n
The non-circulating pressure must then be
adjusted to the required system pressure.
NOTICE!
During manual bleeding, any glycol mixtures
which escape must be disposed of separately.
Do not feed them into the condensate tray!
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