English
pag. 5
8.1 --- Routine maintenance
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
close the panel
In very dusty environments perform this check more frequently.
MICROFACE/HIROMATIC
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 (outer switch 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 there are stillleaks;
repeat the operations from point 4.
8.2.2 -- Refrigerant charge operations.
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 charging hose, connect the cylinder to the liquid line
of the circuit. Drain the substances 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 conditions 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 --Features of the refrigerating fluid R407C
At standard temperature and pressure it is a colourless gas with
low toxicity, non---flammable, and it has an allowed exposure limit
value (AEL/TLV) 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
the same characteristics (see Tab. 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
<---54
_
C
116
23.6 cST
4.7 cST
8.3 --- Dismantling the unit
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 to be 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 recommend 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.
Summary of Contents for Liebert HIROSS TD 06
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