3
11) For maximum protection ensure that all tubing exposed to
low outdoor temperatures is fitted with anti---freeze heaters
and insulated using closed cell synthetic rubber (elasto-
mer);
12) The circuit must include an expansion vessel (with safety
valve) of suitable capacity;
13) Connect the lines avoiding stresses on the machine inner
parts.
Note:
If the water chiller is complete with an expansion vessel (sup-
plied as an option), check if the capacity is enough, and install
a second vessel in the circuit, if required (see par. 8.4).
Follow the indications in Fig. c for the correct sizing.
Note:
The whole circuit must contain a water volume suitable for the
capacity of the installed chiller. Check if the inertial capacity giv-
en by the sum of the hydraulic volume inside the machine (in-
cluding the volume of the optional interna tank, if fitted) and the
system volume issufficient, or possibly installa tank in the circuit.
Follow the indications in Fig. b for the correct sizing.
Note:
The hydraulic circuit must ensure a constant water supply to the
evaporator in every operating condition. Otherwise, the com-
pressors may be damaged by repeated returnsof liquid refriger-
ant on their suction.
Note:
The water flow switch is a compulsory safety component that
must be installed and correctly wired to the Matrix R chillers,
otherwise the guarantee will be invalidated.
It is installed, as standard, on units with the optional on---board
pump set, and is available as a option for units without pumps
on board: in the latter case the flow switch, if not installed on the
machine, can be installed on the hydraulic circuit by the installer,
but it is compulsory that it is wired to the electric panel terminal
board, as indicated on the wiring diagram.
3.2.2 -- Addition of water and ethylene glycol
Very important:
Add water and ethylene glycol to the circuit with a % depending
on the minimum temperature of the outside air expected at the
installation site. Do not exceed the nominal operating pressure
of the circuit’s components.
Notes:
S
To avoid stratification run the circulation pump for at least 30
minutes after adding any glycol.
S
After adding water to the hydraulic circuit
always discon-
nect the water supply coming from the sanitary supply;
this avoids the danger of glycol entering the sanitary water
system.
S
After any topping---up of the water check the concentration
and add glycol if necessary.
3.2.3 -- Water--glycol mixture
Water---glycol mixtures are used as the thermal carrier fluid in
very cold climatesor with temperatures below zero degreescen-
tigrade. Determine the ethylene glycol % which must be added
to the water, with the assistance of Tab. a.
Tab. a --Ethylene glycol to be added to water (% in
weight of total mixture)
Ethylene glycol
(% in weight)
0
10
20
30
40
50
Freezing tempera-
ture,
û
C
(*)
0
---4.4
---9.9
---16.6
---25.2
---37.2
Mixture density at
20
û
C
(*)
, kg/l
---
1.017
1.033
1.048
1.064
1.080
(*) Values are for Shell antifreeze 402. For different brands, check
manufacturer’s data.
For the chiller internal water volume refer to Tab. 1. If the optional
buffer tank is installed on the machine, add the tank hydraulic
volume.
ALWAYS CHARGE THE HYDRAULIC CIRCUIT WITH THE RE-
QUIRED GLYCOL % NECESSARY FOR THE MINIMUM AMBI-
ENT TEMPERATURE AT THE INSTALLATION SITE. FAILING
TO COMPLY WITH THIS INSTRUCTION SHALL INVALIDATE
THE UNIT WARRANTY.
3.3 --- Connection of the safety valve dis-
charge
Safety valves are installed on the high pressure side of the refrig-
eration circuit(s): the discharge of these valves must be con-
veyed outside through a suitable pipe, having a diameter of at
least that of the valve outlet, without burdening the valve body.
Convey the discharge to areas where the jet cannot harm
people and the surrounding environment.
Fig. a --Ideal chilled water circuit
CHILLER
1
1
1
1
3
2
7
4
3
6
9
4
8
11
flow
12
10e
10d
10c
10b
10a
T
T
USER
5
5
9
disconnect af-
ter charge
Vpt
Tank
5
