RHOSS TCHEY 115 Instrucciones De Uso página 39

II.9.1.4 Inspecting the hydraulic circuit
 Check the water differential pressure switch: with unit running,
slowl y clos e the interception val ve positioned by the user on the water
inlet to the unit. If, during a test phase, the point is reac hed where the
isolating val ve is c ompletel y clos ed without the differential pressure
val ve cutting in, s top the unit i mmediatel y by pressi ng ON/OFF on the
control panel and replac e the c omponent.
 Bleeding air from the chilled wat er system : by acti ng on the
relevant bleed val ves positi oned insi de and outside the unit, it is
possible to evac uate the air trapped inside the hydraulic circuit. Al ways
chec k the pressur e of the hydraulic plant and, if necess ary, press urise
with top-up water.
 Circulator pump r elease (only 115- 122 P1)
With the unit off, remove the right side panel and remove the screw that
holds the circulation pump. T urn the r eleas e screw loc ated in the inside,
then put the scr ew that holds the circulation pump bac k i n pl ace.
 Draining the h ydr aulic system: with unit off, if the unit must be
emptied, us e the i nterception val ves on the water inl et and outlet pipes .
Also us e the drain present near to the water connecti ons. In the models
equipped with pump, also us e the drain present on the pump/circulati on
pumps.
 Inspection of the pump/circu lation pump ( wher e present): ever y
5000 functi oning hours of the pump, the circuit board shows an al arm
without interruption of unit functioning. This is a warni ng that the pump
must be inspected. T he i nspection consists in the external cleanliness
and chec ki ng its gener al state.
 W ashing the wat er heat exchangers: pl ate exchangers are not
subject to particul ar fouling in rated runni ng conditions. The wor king
temperatures of the unit, the s peed of the water i n the pipes and the
suitabl e finish of the heat exc hanging surface reduc e fouling of the
exc hangers to a minimum. Any deposits on the heat exchanger can be
detected by meas uring he pressure drop between the inlet pipes and
the unit outlet using a differ ential manometer and comparing the values
with those given in the tables in the attac hments . Any sludge that may
form in the water circuit or any silt that cannot be trapped by the filter,
as well as extremel y hard water c onditions or high c onc entrations of
any antifreeze s oluti on used, may cl og the exc hangers and undermine
their heat exchanging efficienc y. In this c ase, it is necessar y to was h
the exchanger with s uitable c hemical detergents, s etting-up the already
existi ng plant with adequate load and unload c ouplings or inter vening
as in the figure. A tank must be used c ontaining light acid, 5%
phos phoric acid or if the exchanger must be cl eaned frequentl y, 5%
oxalic acid. The detergent liquid must be made to circulate inside the
exc hanger at a fl ow rate of at l east 1.5 ti mes the nominal wor k val ue.
With a first circulati on of the detergent, maximum cleaning is performed,
successi vel y, with clean detergent, the definiti ve cleaning is carried out.
Befor e re-starting the s ys tem, it mus t be rinsed thoroughly to eliminate
all traces of the acid and the air in the s ystem must be bled, eventuall y
be re-starting the us er pump.
1. Unit;
2. Auxiliary val ve;
3. Interception val ve;
4. Washi ng pump:
5. Filter;
6. Acid tank.
SECTION II: INST ALL ATION AND MAINTEN ANCE
II.9.2 EXTRAORDINARY MAINTENANCE
II.9.2.1 Instructions for repairs an replacement of
components
When a component of the refrigerant circuit or the unit must be
replaced, the i ndications given below must be considered:
 Always refer to the wiring diagrams attac hed to the machi ne
whenever and electricall y powered component must be r eplac ed,
making sur e that ever y wire that must be disconnec ted is identified in
order to prevent errors in a succ essi ve re- wiring phase.
 When mac hine functioning is restored, it is al ways nec essar y to
repeat the operations in the start-up phas e.
II.9.2.2 Instructions for emptying the refrigerant
circuit
To empty the entire refrigerant circuit usi ng type- appr oved applianc es,
recover the refrigerant flui d from the high and l ow press ure sides and
also from the liquid line. T he l oad couplings are used, whic h are pres ent
in ever y s ection of the refrigerant circuit All of the circuit lines must be
recovered because onl y in this way is it sur e that all refrigerant fl uid has
been completel y r emoved. If you appl y a brazi ng torch to one of the
low-press ure components of the s ystem, the pressurised mi xture of
refrigerant and oil coul d bl ow out of the circuit and ignite on c ontact with
the brazing torc h. To prevent this ris k, it is i mportant to chec k the
effec tive unload of the press ure on all branc hes, before welding. All of
the refrigerant flui d unloaded c annot be disposed of in the environment
because it is a pollutant, but must be rec overed usi ng suitable
containers and taken to an authorised c ollection centre.
II.9.2.3 Elimination of humidity from the circuit
I humidity is present i nside the machi ne during functioning, it must be
emptied completel y from refrigerant fl uid and the cause of the problem
must be elimi nated. If the humidity is to be elimi nated, the maintenanc e
technician mus t dr y the s ys tem usi ng a vacuum up to 70Pa,
successi vel y the r efrigerant fl uid load c an be restor ed, which is
indicated on the plate positioned on the unit.
II.9.2.4 Replacing the drier filter
To replac e the dryer filter, c arry out emptying and eli minate the humidity
from the refrigerant circuit of the unit, thus evac uati ng the refrigerant
dissolved in the oil.
Once the filter has been replaced, perform the vacuum on the circuit
again to elimi nate any trac es of uncondens ed gas, which may have
entered during the replacement operation. Chec k that there are no gas
leaks befor e putting the unit bac k into normal worki ng conditions.
II.9.2.5 Integration-top-up of the refrigerant load
The units are factor y ins pected with the l oad of gas necess ary for their
correct functioning. The amount of gas contai ned inside the circuit is
indicated directl y on the s erial plate.
If the load of R410A must be reset, the emptying program must be
perfor med along with evacuation of the circuit, eliminating the tr aces of
uncondens ed gas es with any humidity. The gas load must be restored
followi ng a maintenanc e inter vention on the refrigerant circuit followi ng
thorough washi ng of the same. Succ essi vel y, res tore the exact amount
of refrigerant and new oil, as stated on the serial pl ate. The refrigerant
must be drawn from the c ontainer in the liquid state in order to
guarantee the correct proportion of the mi xture (R32/R125).
At the end of the loading operation it is necess ary to repeat the unit
start-up procedure and monitor the unit work conditions for at l east 24
h. If, for particul ar reasons, e.g. a refrigerant l eak a simple top-up is
required, a slight decrease in unit perfor mance mus t be consider ed. In
all cases, reintegration mus t be perfor med on the low pressure branch
of the mac hine, befor e the evaporator, usi ng the press ure points
prepar ed for this purpose; attention must also be paid to introducing
refrigerant only in the liquid s tate.
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