Packaged rooftop units
29
Refrigerant
Only quali
fi
ed personnel must perform a periodic tightness control, in
accordance with the regulation (CE)
Nº 517/2014.
- The frequency of checks is no longer related to the load of refrigerant
but to its global warming potential:
Load kg x GWP = t CO2e
Carbon dioxide equivalency (t CO2e ) is a quantity that describes, for
a given mixture and amount of greenhouse gas, the amount in tonnes
of CO2 that would have the same global warming potential (GWP).
Please, consult data of carbon dioxide equivalency (t CO2e) provided
in the technical characteristics table (chapter 3).
- Operators shall ensure that the unit is checked for leaks ad minima
according to the following frequency:
• t CO2e < 5 ............ not subjected
• t CO2e 5 to 50 ...... every year
• t CO2e 50 to 500 ... every 6 months
• t CO2e > 500 ......... every 3 months
- Where a leakage detection system has been installed the frequency
of checks is halved.
Note: Never forget that the cooling systems contain liquids and vapours
under pressure. The service pressure of R-410A is approximately 1.5
higher than that of R-407C.
- All necessary precautions must be taken during the partial opening
of the cooling circuit. This opening entails the discharge of a certain
amount of refrigerant to the atmosphere. It is essential to limit this
quantity of lost refrigerant to a minimum by pumping and isolating
the charge in some other part of the circuit.
Oil
Oils used for cooling machines do not post any threat to one’s health
if used while following the usage guidelines:
- Avoid any unnecessary manipulation of the elements covered in oil.
Use protection creams.
- Oils are
fl
ammable and must be stored and handled with precaution.
“Disposable” rags or towels used for cleaning must be kept away
from open
fl
ames and must be discarded by using the appropriate
procedure.
- Jugs must be kept closed. Avoid using oil from an already-open jug
kept in poor conditions.
Both the oil type as well as the volume needed for each model are
stated in the characteristics table in chapter 4.
- Check the oil level and aspect. In case of a colour change, check
the oil quality using a contamination test.
- In the case of the presence of acid, water or metallic particles, replace
the affected circuit oil, as well as the dehydrant
fi
lter.
- In the event of an oil charge change, only new oil will be used, which
will be identical to the original oil and taken from a jug tightly closed
until the moment of the charge.
Centrifugal fan (optional)
- Verify that the turbine and the motor remain clean.
- Foresee having a spare belt set for the fans.
- The motors and the fans have bearings that have been lubricated and
sealed and, thus, do not need further lubrication (except in the case
of fans with a reinforced shaft).
Motorised dampers
Servomotors
Damper locked with
the mixing damper
Note:
The available assemblies can be
consulted in chapter 6.
- The refrigerant
fl
uid at low temperature can cause in
fl
ammatory
injuries similar to burns when contacting the skin or eyes. Always
use safety goggles, gloves, etc. when opening ducts that may contain
liquids.
- The refrigerant in excess must be stored in appropriate containers
and the amount of refrigerant stored at the technical rooms must be
limited.
- Refrigerant barrels and deposits must be handled with precaution
and visible warning signs must be placed to attract attention over
the risks of intoxication,
fi
re and explosion linked to the refrigerant.
- At the end of its useful life, the refrigerant must be retrieved and
recycled as per the current regulations.
Refrigerant leak detector (optional)
Maintenance:
- Annual testing: it is necessary to carry
out testing every year to comply with the
EN378 and F-GAS regulations.
- Every 3 years: a taring test is
recommended.
- Every 5/6 years: it is recommended that the gas detection element
be replaced and calibration performed.
Note:
Check the documentation attached to the leak detector for taring
and calibration testing.
In units with mixing box assemblies with
motorised dampers it is advisable to
check the condition of the servomotors.
Assemblies 2 dampers-> 1 servo
Assemblies 3 dampers -> 2 servos
Mixing boxes and free-cooling (optional)
Summary of Contents for 50EH
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