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The following basic guidelines must be observed:
•
Leaks must be repaired immediately by qualified
personnel.
•
Refrigerant must never be discharged to the atmosphere.
•
Use a refrigerant reclaim unit.
•
Any loss of oil from the system during maintenance must
be stopped immediately and the collected oil must by
removed in accordance with applicable regulations
38FZ/BZ and 40TZ/BZ units are supplied with a nitrogen
holding charge. This must be removed before soldering the
connecting refrigerant lines to the unit. Once the soldering has
been completed, the complete refrigerant circuit must be
evacuated then the correct quantity of R-407C refrigerant for
each system must be charged.
WARNING: If any brazing is to be done the refrigerant circuit
must be filled with nitrogen. Combustion of refrigerant
produces toxic phosgene gas.
VERY IMPORTANT:
-
Never use the compressor as a vacuum pump.
-
If more refrigerant is needed add gas very slowly via the
suction line. Liquid refrigerant must never be introduced
into the suction line.
-
Do not overcharge with refrigerant.
START-UP
Actual start-up should only be done under the supervision of a
qualified refrigeration mechanic.
These units incorporate the electronic Master Link II control.
The operation and handling of this control is explained in the
specific instructions accompanying each unit.
Initial checks
With the unit in operation, ensure that the values shown on the
high and low pressure gauges are within the normal limits. It is
advisable to simulate unit shutdown due to high and low
pressure, in order to make sure that the pressurestats work
properly. To do so, proceed as follows:
-
High pressure shutdown:
Completely cover the outdoor
air inlet, or disconnect the outdoor fan and motor. The unit
should stop at a pressure of 2844 kPa.
-
Low pressure shutdown:
Cover the indoor air inlet, or
disconnect the indoor fan and motor. Observe the low
pressure gauge. The unit should stop at a pressure of
265 kPa.
In both cases it is possible to reset the unit through the remote
control as previously indicated.
Check that the motor and compressor consumptions are
approximately the same as those shown on the unit nameplate.
Consumption data is also given in Tables 3 and 4.
Refrigerant system description
The refrigerant circuit incorporates the following primary
elements:
-
Refrigerant-air heat exchanger:
made of high quality
copper tubes and pretreated aluminium fins, for extra
corrosion resistance and greater protection than offered by
copper fins.
-
Refrigerant lines:
made completely of high quality
copper.
-
Metering device
.
-
Compressors:
hermetic compressors for all units, cooled by
suction gas. They incorporate internal protection.
-
Filter drier and Schrader valves.
-
Safety elements:
high, low pressurestat.
-
The packaged units are supplied with the exact refrigerant
charge.
-
The split-system units are supplied with a nitrogen hold-
ing charge which must be evacuated and replaced with the
right refrigerant charge for the unit size and the connection
lines.
Compressor replacement
When an internal fault occurs, the compressor must be
replaced. This must be done as detailed below:
-
Disconnect the unit from the electrical supply.
-
Remove the panels.
-
Remove the gas from the refrigerant circuit using recovery
equipment to avoid harming the atmosphere.
-
Electrically disconnect the compressor.
-
Unbraze or unscrew the suction and discharge lines,
taking care not to damage the rest of the components.
-
Remove the fastenings from the compressor.
-
Replace the compressor, ensuring that it contains
sufficient oil.
-
Braze or screw in the lines.
-
Connect the compressor according to the wiring diagram.
-
Evacuate the compressor.
-
Fill the refrigerant charge indicated on the nameplate, plus
the required charge for the refrigerant connection lines.
NOTE: This operation must be done by a qualified technician.
Description of unit protection devices
The unit includes the following compressor protection devices:
-
Internal compressor protection device
to avoid superheat.
-
Short-cycle protection
(included on the main electronic
board).
-
Outdoor fan motor thermomagnetic switch.
-
High pressurestat:
This protects the unit against
excessive condensing pressure. The high pressurestat has
factory-fixed non-adjustable settings. To check, see
section Initial checks.
-
Low pressurestat:
This protects the unit against
excessive low pressure in the evaporator. The low
pressurestat has factory fixed non-adjustable settings. To
check, see section Initial checks.
CAUTION: When any of these cuts out, the unit stops and will
not re-start until the contacts have been reclosed after
rectification of the fault.