Installation; Water Connections; Supply Water Specifications; Refrigerant Connections - Carel Heosbox Mode D'emploi

The unit is installed and commissioned as described below; please see the
Carel "Heos" manual (+0300078EN) for details on programming.
Notice: the water and refrigerant connections are located on the
opposite side to the electrical connections (Fig.4.a):
36
34 35
Ref. Description
23 Water inlet connection:
1" NPT threaded male (NAM vers.)
36 Water outlet connection:
1" NPT threaded male (NAM vers.)
34 Refrigerant inlet connection
(*)
35 Refrigerant outlet connection (*)
Notice: the water and refrigerant connections are located on the
(*)
opposite side to the electrical connections, as shown in the figure: the
refrigerant connections are made using pipe couplings whose diameter
and thickness varies according to the size of the unit, see "Refrigerant
connections".

4.1 Water connections

Refer to Figure 4.a.
Caution: before continuing, make sure the unit is powered off,
placing disconnect switch QS1 and the switch or disconnect device on the
Heosbox power supply line in the OFF position (see the wiring diagram).
The mains power disconnect device must have a contact opening
distance that allows complete disconnection in overvoltage category III
conditions; it must also be incorporated into the Heosbox power supply
line in accordance with national regulations.
To simplify installation and maintenance:
• install a manual shut-off valve immediately before the water inlet to the
unit (the valve is not supplied by CAREL);
• install automatic air vent valves (not supplied by CAREL) in the piping, at
the highest positions in the circuit;
• avoid piping layouts in which water may stagnate when the system is
stopped;
• fit appropriately-sized expansion vessels to avoid water hammer from
damaging the system;
• install mechanical and/or magnetic filters to minimise the presence of
impurities in the circuit.
Caution: the water connections must always be completed by
qualified personnel who have the qualifications and authorizations
required by local regulations, using appropriate personal protective
equipment (PPE), who are aware of the necessary precautions and who are
able to correctly and safely complete all required operations.
Caution: the SP and ST values for the water circuit connected to the
Heosbox refer to the lowest SP or ST of all the components in the circuit.

4. INSTALLATION

23
Fig. 4.a
The unit's water connections have 1" NPT for NAM versions; the unit should
be connected to the water loop without any reductions in diameter, as
such reductions may affect the unit's performance or cause malfunctions.
The water circuit must be thoroughly cleaned of any processing residues
(shavings, dust, etc.) before being connected to the unit. It is recommended
to install an inspectable "Y" filter at the inlet to each condenser to ensure
adequate protection. It is recommended to use a filter with the same
diameter as the piping (1") and with a filtration capacity of at least 400 μm
or finer. Regular maintenance must be performed on the inspectable filter
so as to ensure correct operation of all the units connected to the water
loop. The diameter of the water loop piping and the pressure head at the
inlet to each individual Heosbox unit must be sized so as to ensure a water
flow-rate at the condenser inlet in compliance with the nominal flow-rate
stated in this document under "Technical Specifications".
All of the units have been designed to give a water-side pressure drop
of about 30 kPa, so as to simplify installation in a loop with multiple units
connected in parallel. By maintaining a pressure drop of 30 kPa between
the condenser inlet and outlet on each unit, the water flow-rate to the
condenser is certain to be approximately equal to the value required for
correct operation of the unit, as declared in the "Technical Specifications".
The installer is responsible for the correct construction and balancing of
the water circuit. Carel Industries S.p.A. declines all liability for water loop
installations that do not comply with the aforementioned instructions and
in such cases does not guarantee correct operation of the unit.
Tab. 4.a

4.2 Supply water specifications

The HEOS box units are designed to work with mains water mixed with
ethylene glycol (antifreeze additive), with a concentration in proportion to
the total volume of the water loop equal to:
• Nominal*: 20%;
• Minimum: 10%;
• Maximum: 50%.
Notice: (*) reference percentage for unit performance shown in the
"Technical Specifications".
Use of antifreeze additive:
• is a necessary precaution if the water loop is served by a dry cooler and
the outside temperature drops below 0°C.
• is mandatory for systems that use chillers to cool the water loop.
• is good practice to prevent corrosion and ensure constant water circuit
performance over time.
• inhibited propylene glycol with a minimum concentration of 10% and
a maximum of 52% by volume can be used. As propylene and ethylene
glycol have different thermal properties, performance of the Heosbox
unit may differ from the values shown in the "Technical Specifications".
Caution: read the safety and technical data sheet for the antifreeze
additive before handling the fluid and adding it to the water circuit.

4.3 Refrigerant connections

Refer to Figure 4.a.
Caution: before continuing, make sure the unit is powered off,
placing disconnect switch QS1 and the switch or disconnect device on the
Heosbox power supply line in the OFF position (see the wiring diagram).
The mains power disconnect device must have a contact opening distance
that allows complete disconnection in overvoltage category III conditions; it
must also be incorporated into the Heosbox power supply line in accordance
with national regulations. The refrigerant connections supplied are stubs of
bare copper pipes with variable diameter and thickness, depending on the
size of the unit. It is good practice to use copper pipes of the same type
and with the same diameter as those coming out of the unit, avoiding
differences in diameter of more than one size.
17 Heos BOX - NAM version +0300097EF - rel. 1.0 - 17.06.2021
ENG