Hitecsa EWMIM Serie Manual De Instalación, Uso Y Mantenimiento página 80

Control
Electrical system
Check the power consumption of the unit
Check electrical control board contactors
Fans
Electric motor of fans
Checking gas charge and humidity in
circuit (with unit running at full capacity)
Check that there are no gas leaks
Verify operation of pressure switches
of maximum
Bleeding air from the chilled water system
Draining the water system (if
necessary)
II.11.2.1 Component replacement instructions
If a unit requires repair, switch it off and recover the refrigerant fluid
from both the high and low-pressure sides and in the liquid line. This is
because, if the coolant is only drained from the high pressure side, the
compressor springs may close together, thereby preventing the
pressure from equalising. In this way, the low pressure part of the
casing and the inlet line could remain pressurised. In this case, if you
apply a brazing torch to one of the low-pressure components of the
system, the pressurised mixture of refrigerant and oil could blow out of
the circuit and ignite on contact with the brazing torch. To prevent this
risk it is important to make sure that the pressure on the high and low
pressure sides have actually been drained before desoldering.
IOM_EWMIM-EWMIMH_120a262_207984_200601_ES-EN-FR-DE-IT
Frequency
Every 6 months
Every 6 months
In the case of installation with harsh
operating conditions, increase the
frequency of the control.
Every 6 months
Every 6 months
In the case of installation with harsh
operating conditions, increase the
frequency of the control.
Every 6 months
In the case of installation with harsh
operating conditions, increase the
frequency of the control.
Every 6 months
Every 6 months
Every 6 months
Every 6 months
II.11.2.2 Top-up l replacement of refrigerant charge
The units are factory-tested with the gas charge necessary for correct
operation. The amount of gas inside the circuit is indicated in the serial
number plate.
In the event the R410A charge must be restored, drain the circuit,
removing any trace of non-condensable gases with humidity. After
maintenance operations on the cooling circuit and before restoring the
gas charge, wash the circuit thoroughly. Then top-up the exact amount
of new oil and refrigerant as shown on the serial no. plate. The
refrigerant must be drawn from the cylinder as liquid so as to guarantee
the correct mixture proportion (R32/R125). Once the topping-up
operation is complete, repeat the unit start-up procedure and monitor its
operating conditions for at least 24 hours.
In the event that, for special reasons, for example in the event of a
refrigerant leak, it is preferable to proceed with a simple refilling of
refrigerant, a slight deterioration of the performance of the unit should
be considered. In all cases the top-up must be carried out in the low
pressure section of the machine before the evaporator, using the
pressure sockets; make sure that the refrigerant is introduced only in
the liquid phase.
82
Notes
Besides checking the various electrical devices, the
electrical insulation of all the cables and their correct
tightening on the terminal boards must be verified,
paying special attention to the earth connections.
This operation must be carried out by skilled
personnel of authorised HITECSA workshops,
qualified to operate on this type of products.
Make sure the motors and fan blades are clean and that
there are no abnormal vibrations.
The motor must be kept clean with no traces of
dust, filth, oil or other impurities. These could
cause it to overheat due to low heat dissipation.
The bearings are usually watertight with permanent
lubrication and sized in order to last approximately
20.000 hours in standard operational and
environmental conditions.
With the unit off, fit a pressure gauge on the test
point on the outlet side and another on the test
point on the inlet side. Start up the unit and check
both pressure readings once they have stabilised.
With the unit off, check the refrigerant circuit with a
suitable leak detector.
This operation must be carried out by skilled
personnel of authorised HITECSA workshops,
qualified to operate on this type of products.
Bleeding the air is facilitated by manual valves
found inside the unit, which are accessed by
opening the panelling of the technical compartment
The emptying is necessary in case the machine does not
work during the winter season. Alternatively a glycol
mixture can be used according to the information
reported in this manual.
ADVANCE