Idiomas disponibles
Idiomas disponibles
II.6.5
PROTECTING THE UNIT FROM FROST
IMPORTANT!
If open, the mains switch cuts off the power supply
to the plate exchanger electric heater, the buffer
tank antifreeze electric heater (RAA accessory) and
the compressor crankcase heater (RCC accessory
for models 114÷124, as standard on 127÷233). The
switch should only be disconnected for cleaning,
maintenance or repair of the machine.
When the unit is running, the control board protects the water-side heat
exchanger from freezing by making the antifreeze alarm cut in, stopping
the machine if the temperature of the sensor fitted on the heat
exchanger reaches the set point value.
IMPORTANT!
When the unit is out of service, drain all the water
contents from the circuit.
If the draining operation is felt to be too much trouble, ethylene glycol
may be mixed with the water in suitable proportions in order to
guarantee protection from freezing.
IMPORTANT!
Mixing the water with glycol modifies the
performance of the unit.
The use of ethylene glycol is recommended if you do not wish to drain
the water from the hydraulic system during the winter stoppage, or if the
unit has to supply chilled water at temperatures lower than 5°C The
addition of glycol changes the physical properties of the water and
consequently the performance of the unit. The proper percentage of
glycol to be added to the system can be obtained from the most
demanding operating conditions from those shown below. Table "H"
shows the multipliers which allow the changes in performance of the
units to be determined in proportion to the required percentage of
ethylene glycol.
The multipliers refer to the following conditions: condenser inlet air
temperature 35°C; chilled water outlet temperature 7°C; temperature
differential at evaporator 5°C. For different operating conditions, the
same coefficients can be used as their variations are negligible.
Table "H"
% glycol in
10 %
weight
Freezing
temperature °C
fc QF
0,991
fc P
0,996
fc ∆ pw
1,053
fc G
1,008
fc QF = Cooling capacity correction factor.
fc P= Correction factor for the absorbed electrical current.
fc ∆ pw
= Correction factor of the pressure drops in the evaporator
fc G
= Correction factor of the glycol water flow to the evaporator
II.7
ELECTRICAL CONNECTIONS
DANGER!
Always install a general automatic switch in a
protected area near the appliance with a
characteristic delayed curve, sufficient capacity and
breaking power and with a minimum distance of 3
mm between the contacts. Earth connection is
compulsory by law and safeguards the user while
the machine is in use.
DANGER!
Electrical connection of the unit must be carried out
by personnel skilled in the matter and in
compliance with the regulations in effect in the
country where the unit is installed. Non-conforming
electrical connection relieves
responsibility for damage to persons and property.
In making the electrical connections to the board,
cables must be routed so that they do not touch the
hot parts of the machine (compressor, flow pipe
and liquid line). Protect the wires from any burrs.
IMPORTANT!
For electrical connections to the unit and the
accessories, follow the wiring diagrams which are
supplied with them.
The safety door interlock automatically prevents electric power being
fed to the unit if the cover panel over the electrical panel is opened.
After opening the front panel of the unit, feed the supply cables through
the appropriate cable clamps in the external panelling and then through
the cable clamps at the base of the electrical board.
The electrical power supplied by the single-phase or three-phase line,
must be taken to the main isolator switch. The supply cable must be of
the flexible type, with polychloroprene sheathing of no lighter than
H05RN-F: for the section, refer to the table below or the wiring diagram.
122
mm²
127
mm²
130
mm²
The earth conductor must be longer than the other conductors in order
to ensure that in the event of the cable clamping device becoming
slack, it will be the last to come under strain.
33
Compact-Y SM
15 %
20 %
25 %
-5
-7
-10
-13
0,987
0,982
0,978
0,995
0,993
0,991
1,105
1,184
1,237
1,028
1,051
1,074
S.p.A. from all
RHOSS
6
6
1,5
10
10
1,5
10
10
1,5
30 %
-16
0,974
0,989
1,316
1,100
