Ferroli RXA, Техническое руководство

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17
CONNECTIONS
Plumbing connections
For correct design of the plumbing system comply with the current local safety regulations.
Always ensure an adequate flow of water through the unit’s plate-type exchanger, even if a differential pressure switch
(connected between the exchanger inlet and outlet) that stops the unit in case of insufficient water flows, thus preventing the risk
of freezing, is fitted standard. For that purpose, an antifreeze heating element is also fitted on the plate-type exchanger of all the
units.
To adjust the water flow through the exchanger it is advisable to install a cock at the outlet of the unit.
Basic version (VB) units must be fitted with a mesh filter (Ø holes
≥
500 µm) at the plate-type exchanger inlet to catch
any foreign substances; the warranty is cancelled if this filter is not fitted .
The plumbing circuit must be kept under pressure using an expansion tank in combination with a safety valve (these parts are
already present in the storage version - VA). A filling unit that automatically fills the system and maintains the required pressure
can be used.
Precautions during the winter period
In case of a system stop during the winter period, the water could freeze and damage the unit’s exchanger and other parts of
the system. To prevent these problems, three solutions are possible:
1.
Completely drain the system, paying attention to emptying the plate-type exchanger (open the air vents to facilitate the
operation).
2. Use water with glycol remembering that, according to the quantity of glycols used, the unit’s performance must be adjusted
by means of correction factors for the refrigerating capacity, input, water delivery and pressure losses.
3. Keep the unit electrically connected throughout the winter. The plate-type exchanger is protected by the antifreeze heating
element fitted standard. The circulating pump is activated by the unit’s controller according to the outside air temperature,
to protect the pipes. Units in storage version (VA) are supplied with an antifreeze heating element, as an accessory to
prevent ice forming inside the tank, activated by the unit’s controller together with the antifreeze heating element of the
plate-type exchanger. The supplementary heating elements, if present, also carry out the antifreeze function.
Suggestions for the plumbing system
Prepare the pipes with the least possible number of bends to minimise pressure losses, and suitably support them to prevent
excessive stresses at the unit’s connections.
Install shut-off valves near the parts subject to maintenance, to allow their replacement without having to drain the system.
Provide for manual or automatic valves in the highest part of the circuit to vent the air.
Make sure there are no leaks before insulating the pipes and filling the system.
Insulate all the refrigerated water pipes to prevent the formation of condensate, using steam barrier type material (otherwise
cover the insulation with appropriate protection). Also make sure the air vent valves are always accessible.
Arrange adequate connections for reading the pressure and temperature at the inlet and outlet of the unit, for possible control of
correct system operation.
Coil condensate drain
The condensate produced by the coil during heating operation is collected in the tray obtained in the base of the unit and can be
drained by connecting a tube to the union supplied standard on all units in heat pump version.