19
INXWPY. 1610. 4438880_01
8.
HYDRAULIC CIRCUIT
The NXW standard version is comprised of a circuit including:
−
Evaporator (plate type exchanger)
−
Condenser (plate type exchanger)
−
Water inlet probe SIW
−
Water outlet probe SUW
NB:
Water filter versions standard: NOT INCLUDED
the weld pipe is supplied as
standard with the VICTAULIC connection is included
The NXW version with pumping group also includes:
−
Circulation pump
−
Water filter
−
Drain valve
−
Flow switch
−
Water outlet/inlet probe
−
Expansion tank (25 litres)
8.1.
EXTERNAL HYDRAULIC CIRCUIT RECOMMENDED
The selection and installation of components outside the NXW
should be carried out by the installer, who should work ac-
cording to the technical code of practice and in compliance
with the legislation in force in the country of destination (MD
329/2004).
Before connecting the pipes make sure that they do not contain stones,
sand, rust, slag or any foreign bodies that may damage the system. It
is necessary to make a by-pass to the unit to be able to carry out the
cleaning of the pipes without having to disconnect the machine. The
connection pipes must be properly supported so as not to burden the
unit with their weight.
On the water circuit, it is advisable to install the following instruments, if not
foreseen in the version you have:
1. Two pressure gauges of suitable size
(input and output section).
2. Two anti-vibration couplings (input and output section).
3. Two shut-off valves (normal input section, output section calibrating
valve).
4. Two thermometers (input and output section).
5. Expansion tanks
6. pump
7. Accumulation tank
8. Flow switch
9. Safety valve
10. Charging unit
11. Water filter
11.
The filter protects only the exchangers (in case of
particularly dirty water, we recommend an external filter
to protect the pumps)
Compulsory hydraulic circuit compnents (in case of an NXW provided without
the hydronic kit (evaporator side, condenser side):
- At the inlet or each plate heat exchanger the installation of a flow switch
(not included) is compulsory at the penalty of invalidating the warranty.
- Installation of the mechanical filter is compulsory
at the inlet of each plate heat exchanger at the penalty of invalidating
the warranty. The filter must have filtering holes with a diameter not
greater than one millimetre and must be kept clean, therefore the
cleaning must be verified after installation of the unit and the condition
must be checked periodically.
It is necessary, that the water flow rate to the chiller unit complies with
the values reported in the performance tables.
The systems loaded with anti-freeze or specific regulations, need the
water backflow system.
Special supply/recovery water, is carried out with appropriate treatment
systems.
8.2.
SYSTEM LOAD
−
Before starting the load, check that the system drain tap is closed.
−
Open all the drain valves of the system and of the related terminals.
−
Open the shut-off devices of the system.
−
Start the filling by slowly opening the water system load cock placed
outside the machine.
−
When water begins to flow from the terminal vent valves, close them and
continue loading up to read on the gauge the value of 1.5 bar.
The system is loaded at a pressure between 1 and 2 bar.
It is advisable to repeat this operation once the machine has worked for some
hours and to periodically check the system pressure, restoring if it drops below
1 bar.
Check the hydraulic seal of the joints.
8.3.
EMPTYING THE SYSTEM
−
Before starting to drain the system, turn “off” the unit
−
Check that the water system load/restore tap is closed
−
Open the drain tap outside the machine and all the vent valves of the
system and the corresponding terminals.
If the system uses glycol, this liquid should not be drained
to the environment because it is a pollutant. It must be col-
lected and, if possible, reused.
HYDRAULIC CIRCUIT KEY
( PUMP VERSION)
1 Condenser
2 Evaporator
3 Flow switch
4 pumps
5 Air bleed valve
6 Water discharge
7 Filter
8 Expansion tank
NB
The Victaulic joints and the soldering
studs for the condenser and
evaporator are provided
Example of NXW Version [H]
2
3
4
5
7
8
1
WATER FEATURES
Water features
System: Chiller with plate heat exchanger
PH
7,5-9
Electric conductivity
100-500μS/cm
Total hardness
4,5-8,5 dH
Temperature
< 65°C
Oxygen content
< 0,1 ppm
Max. glycol amount
0,5
Phosphates (PO4)
< 2ppm
Manganese (Mn)
< 0,05 ppm
Iron (Fe)
< 0,3 ppm
Alkalinity (HCO3)
70 - 300 ppm
Chloride ions (Cl-)
< 50 ppm
Sulphate ions (SO4)
< 50 ppm
Sulphide ion (S)
none
Ammonium ions (NH4)
none
Silica (SiO2)
< 30ppm
