Daikin SERHQ020BAW1, Инструкция для установки и пользователя

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5 Preparation
Installer and user reference guide
15
SERHQ020~0 SEHVX20~64BAW
Split packaged air-cooled water chiller
4P508020-1B – 2018.04
When multiplying 64 l by the correction factor, we get 224 l, which
will be the minimum water volume allowed in the installation if a
temperature differential of 1 K is used.
Now it is very important to check that for the height difference of the
system, the volume in the system is less than the maximum allowed
value at that pre-pressure (Pg). If we take a look at the curve, for
1 bar of pre-pressure, the maximum volume allowed is 350 l.
The total volume in the system will definitely be larger after adding
the internal volume of the unit. In this case, some pre-pressure can
be applied or an additional expansion vessel or buffer tank must be
installed in the field piping.
The default value of pre-pressure (Pg) is for a height difference of
7 m.
If the height difference of the system is lower than 7 m AND the
volume in the system is less than the maximum allowed value at that
pre-pressure (Pg) (see graph), then NO pre-pressure (Pg)
adjustment is required.
Maximum water volume
Use the following graph to determine the maximum water volume for
the calculated pre-pressure.
0
0.5
1
1.5
2
2.5
3
0 50 100 150 200 250 300 350 400 450 500 550 600
A
B
33
b
a
a Pre-pressure (bar)
b Maximum water volume (l)
A System
B Default
If the total water volume in the entire circuit exceeds the maximum
allowed water volume (see graph), an additional expansion vessel
must be installed in the field piping.
5.4.4 Changing the pre-pressure of the
expansion vessel
NOTICE
Only a licensed installer may adjust the pre-pressure of the
expansion vessel.
When changing the default pre-pressure of the expansion vessel
(1 bar) is required, take following guidelines into account:
▪ Only use dry nitrogen to set the expansion vessel pre-pressure.
▪ Inappropriate setting of the expansion vessel pre-pressure will
lead to malfunction of the system.
Changing the pre-pressure of the expansion vessel should be done
by releasing or increasing nitrogen pressure through the Schrader
valve of the expansion vessel.
a
a Schrader valve
5.4.5 To check the water volume: Examples
Example 1
The unit is installed 5 m below the highest point in the water circuit.
The total water volume in the water circuit is 250 l.
No actions or adjustments are required.
Example 2
The unit is installed at the highest point in the water circuit. The total
water volume in the water circuit is 420 l.
Actions:
▪ Because the total water volume (420 l) is more than the default
water volume (340 l), the pre-pressure must be decreased.
▪ The required pre-pressure is:
Pg=(0.3+(H/10)) bar=(0.3+(0/10)) bar=0.3 bar
▪ The corresponding maximum water volume is approximately 490 l
(see graph).
▪ Because 420 l is lower than 490 l, the expansion vessel is
appropriate for the installation.
5.5 Preparing electrical wiring
5.5.1 About preparing electrical wiring
INFORMATION
Also read the precautions and requirements in the
"General safety precautions" chapter.
WARNING
▪ If the power supply has a missing or wrong N-phase,
equipment might break down.
▪ Establish proper earthing. Do NOT earth the unit to a
utility pipe, surge absorber, or telephone earth.
Incomplete earthing may cause electrical shock.
▪ Install the required fuses or circuit breakers.
▪ Secure the electrical wiring with cable ties so that the
cables do NOT come in contact with sharp edges or
piping, particularly on the high-pressure side.
▪ Do NOT use taped wires, stranded conductor wires,
extension cords, or connections from a star system.
They can cause overheating, electrical shock or fire.
▪ Do NOT install a phase advancing capacitor, because
this unit is equipped with an inverter. A phase
advancing capacitor will reduce performance and may
cause accidents.