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1 - INTRODUCTION
• Carry out periodic leak tests. In the European Union,
article 2 of regulation (EU) No.517/2014 makes these
mandatory and sets their frequency. The table below
shows this frequency, as originally published in the
regulation. Check whether an inspection frequency is
also set by other regulations or standards applicable
to your system (e.g. EN 378, ISO 5149, etc.).
A logbook must be established for the systems
that require a tightness check. It should contain
the quantity and the type of fluid present within the
installation (added and recovered), the quantity of
recycled fluid, the date and output of the leak test,
the designation of the operator and its belonging
company, etc.
Leak test periodicity:
System WITHOUT
No test
leakage detection
System WITH leakage
No test
detection
Refrigerant charge per
< 5 tons
circuit (equivalent CO
)
2
R134a
Charge
(PRP 1430)
< 3.5 kg
R407C
Charge
(PRP 1774)
< 2.8 kg
R410A
Charge
(PRP 2088)
< 2.4 kg
HFOs: R1234ze
*
From 01/01/2017, units must be equipped with a leak detection system.
• During the life-time of the system, inspection and tests
must be carried out in accordance with national
regulations.
Protection device checks (EN 378):
The safety devices must be checked on site once a year for
safety devices (see chapter 11.3 - High-pressure safety
switch), and every five years for external overpressure
devices (external relief valves).
The company or organisation that conducts a pressure switch test
shall establish and implement a detailed procedure to fix:
- Safety measures
- Measuring equipment calibration
- Validating operation of protective devices
- Test protocols
- Recommissioning of the equipment.
Consult the manufacturer Service for this type of test. The
manufacturer mentions here only the principle of a test without
removing the pressure switch:
- Verify and and record the set-points of pressure switches
and relief devices (valves and possible rupture discs)
- Be ready to switch-off the main disconnect switch of the power
supply if the pressure switch does not trigger (avoid over-
pressure or excess gas in case of valves on the high-pressure
side with the recovery condensers)
- Connect a pressure gauge protected against pulsations (filled
with oil with maximum pointer if mechanical), preferably
calibrated (the values displayed on the user interface may
be inaccurate in an instant reading because of the scanning
delay applied in the control)
- Complete an HP Test
- Neutralize HP soft protection
- Cut condenser water flow
6
12
6 months 3 months
months
24
12
6 months
months
months
5 ≤
50 ≤
Charge >
charge <
charge <
500
50 tons
500 tons
tonnes*
3.5 ≤
34.9 ≤
charge >
charge
charge <
349.7 kg
< 34.9 kg
349.7 kg
2.8 ≤
28.2 ≤
charge >
charge
charge <
281.9 kg
< 28.2 kg
281.9 kg
23.9 ≤
2.4 ≤
charge
charge >
charge
< 239.5
239.5 kg
< 23.9 kg
kg
No requirement
- Check the cut-off value
- Reactivate manually HP switch and reactivate HP soft value"
- Repeat the procedure for each unit compressor.
CAUTION:
If the test leads to replacing the pressure switch, it is
necessary to recover the refrigerant charge, these pressure
switches are not installed on automatic valves (Schraeder
type).
At least once a year thoroughly inspect the protection devices
(valves). If the machine operates in a corrosive environment,
inspect the protection devices more frequently.
Ensure regularly that the vibration levels remain acceptable
and close to those at the initial unit start-up.
Before opening a refrigerant circuit, purge and consult the
pressure gauges.
Change the refrigerant when there are equipment failures,
following a procedure such as the one described in NF E29-
795 or carry out a refrigerant analysis in a specialist
laboratory.
If the refrigerant circuit remains open for longer than a day
after an intervention (such as a component replacement), the
openings must be plugged and the circuit must be charged
with nitrogen (inertia principle). The objective is to prevent
penetration of atmospheric humidity and the resulting
corrosion on the internal walls and on non-protected steel
surfaces.
1.4 - Repair safety considerations
It is compulsory to wear personal protection equipment.
The insulation must be removed and warming up must be
limited by using a wet cloth.
Before opening the unit always ensure that the circuit has
been purged.
If work on the evaporator is required, ensure that the piping
from the compressor is no longer pressurised (as the valve
is not leaktight in the compressor direction).
All installation parts must be maintained by the personnel in charge,
in order to avoid material deterioration and injuries to people. Faults
and leaks must be repaired immediately. The authorized technician
must have the responsibility to repair the fault immediately. Each
time repairs have been carried out to the unit, the operation of the
protection devices must be re-checked.
Comply with the regulations and recommendations in unit and
HVAC installation safety standards, such as: EN 378, ISO 5149,
etc.
If a leak occurs or if the refrigerant becomes contaminated (e.g.
by a short circuit in a motor) remove the complete charge using
a recovery unit and store the refrigerant in mobile containers.
Repair the leak detected and recharge the circuit with the total
R-134a charge, as indicated on the unit name plate. Certain parts
of the circuit can be isolated. Only charge liquid refrigerant R-134a
at the liquid line.
Ensure that you are using the correct refrigerant type before
recharging the unit
The compressors operating are NOT lubricated. Charging any
oil type will impair machine operation and lead to a destruction
of the compressor.
Charging any refrigerant other than the original charge type
(R-134a) will impair machine operation and can even lead to
a destruction of the compressors.
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