Englishpag. 5
8.1 --- Routine mainten ance
Maintenance program --- Monthly check
FANS
Check that the fan motor rotates freely without any abnormal noise, and ensure that the bearings
are not running hot. Also check the current absorption.
AIR FILTERS
Check the filter conditions; if necessary clean or replace them.
How to replace:
S open the middle panel and remove filter cover
S vertically pull the metal pre---filter out and blow carefully
S extract the filter from its seat horizontally
S introduce the spare part
S cl ose the panel
In very dusty environments perform this check more frequently.
MICROF ACE/HIROMA TIC Verify the operation of the MICROFACE/HIROMATIC’s LEDs, display and alarms.
ELECTRICAL CIRCUIT
S Check the power supply on all phases.
S Ensure that all electrical connections are tight.
REFRIGERATION CIRCUIT
S Check the evaporating pressures (to be performed by a refrigeration technician).
S Check the compressor current absorption, the head pressure and the presence of any unusual
noise.
S Ensure that there is no ice formation on the evaporator.
8.2 --- Extraordinary maintenance
8.2.1 -- Check of the system vacuum and leaks.
Note: Before proceeding, recover all the refrigerant, according
to the local laws.
1) Switch the unit off (outerswitch on OFF) and cut off opening
the switch QF1 and QF2 (if present).
2) Remove the panels necessary for inspecting the refrigerat-
ing circuit.
3) Connect a high efficiency vacuum pump to the needle
valves (Schräder) on the gas and liquid lines; also arrange
a connection with a nitrogen bottle.
4) Load the circuit with nitrogen (7 bar/700 kPa). Find possible
leaks in the circuit by soapy water or other specific product
(foaming agents), and repair as necessary.
5) Drain the circuit by a vacuum of 0.3 mbar absolute .
6) After 3 hours check not to have exceeded 1.3 mbar abso-
lute; this condition ensures a humidity lower than 50 ppm in-
side the system. If the vacuum is notkept thereare stillleaks;
repeat the operations from point 4.
8.2.2 -- Refrigerant charge o perations.
After having eliminated the humidity from the refrigerating cir-
cuit (see 8.2.1), proceed as
follows:
1) Make sure all the unit components are in operating order.
2) Using a charginghose,connectthecylinder to the liquid line
of the circuit. Drain the substance s that cannot be con-
densed from the hose.
Charge the circuit exclusively with the refrigerant
indicated on the identification label.
Charge the quantity of refrigerant indicated in Tab. 1.
3) Close the main switch QS1 and position the outer switch on
ON.
4) Start the compressor.
5) The charge operation can be considered finished when,
keeping the condensation temperature at a steady level
(~ 50°C, if necessary partially clog the condensing coil), no
more bubbles appear for at least ten minutes. Check if the
superheat in these condit ions is 7÷8 degrees.
Superheat calculation
a) With the unit operating in standard conditions, mea-
sure the temperature of the suction line in the point
where the bulb of the thermal expansion valve is fas-
tened.
b) Detect the evaporation pressure gauge temperature
from a pressure gauge placed on the compressor suc-
tion.
c) Subtract the obtained temperature value from the one
measured in point a). The difference is the su-
perheat value.
8.2.3 -- R407C refrigerant units
8.2.3.1 --F eatures of the refri gerati ng fluid R407C
At standard temperature and pressure it is a colourless gas with
low to xicity , non- --flammable, and it has an all owed exposure limit
value (AEL/TL V) corresponding to 1000 ppm (average value mea-
sured on 8 hours/day). In the event of leakage, air the room be-
fore use.
Tab. 1 --- R407C refrigerant charge
MODEL
TD 06 TD 08 TD 10 TD 14
Kg 3.0 3.2 3.5 3.7
R407C
The oil to be used when topping up is MOBIL EAL ARCTIC
22CC; if MOBIL EAL ARCTIC 22CC is unavailable use an oilwith
thesamecharacteristics(seeTab.2).
NEVER MIX DIFFERENT OILS TOGETHER. CLEAN THE PIP-
ING COMPLETELY BEFORE CHANGING THE TYPE OF OIL
USED.
Tab. 2 --- Mobil Eal Arctic 22CC oil (standard)
approx. specific weight (at 15_C)
flash point (C.O.C.)
pour point
viscosity index
viscosity at 40_C
viscosity at 100_C
:
:
:
:
:
:
0.99 kg/l
245 _C
< --- 5 4 _C
116
23.6 cST
4.7 cST
8 . 3 --- D i s m a n t l i n g t h e u n i t
The machine has been designed and built to ensure continu-
ous operation.
The working life of some of the main components, such as the
fan and the compressor, depends on their maintenance. If the
unit has tobe dismantled, this must be done by skilled refrigera-
tor technicians.
The refrigerating fluid and the lubricating oil in the circuit must
be disposed of in conformity with the laws in force in your coun-
try.
8.4 --- Spare parts
We reco mmend the use of original spare parts. When placing
an order please refer to “Component List” enclosed with the
machine and specify the unit model and serial no.
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