37MARAQ: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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5. Presence of fire extinguisher
If any hot work is to be conducted on the refrigeration equipment or any
associated parts, appropriate fire extinguishing equipment shall be
available to hand. Have a dry power or CO2 fire extinguisher adjacent to
the charging area.
6. No ignition sources
No person carrying out work in relation to a REFRIGERATING
SYSTEM which involves exposing any pipe work shall use any sources
of ignition in such a manner that it may lead to the risk of fire or
explosion. All possible ignition sources, including cigarette smoking,
should be kept sufficiently far away from the site of installation,
repairing, removing and disposal, during which refrigerant can possibly
be released to the surrounding space. Prior to work taking place, the area
around the equipment is to be surveyed to make sure that there are no
flammable hazards or ignition risks. “No Smoking” signs shall be
displayed.
7. Ventilated Area
Ensure that the area is in the open or that it adequately ventilated before
breaking into the system or conducting any hot work. A degree of
ventilation shall continue during the period that the work is carried out.
The ventilation should safely disperse any released refrigerant and
preferably expel it externally into the atmosphere.
8. Checks to the refrigeration equipment
Where electrical components are being changed, they shall be fit for the
purpose and to the correct specification. At all times the manufacturer’s
maintenance and service guidelines shall be followed. If in doubt consult
the manufacturer’s technical department for assistance. The following
checks shall be applied to installations using FLAMMABLE
REFRIGERANTS:
• the actual refrigerant charge is in accordance with the room size
within which the refrigerant containing parts are installed;
• the ventilation machinery and outlets are operating adequately and are
not obstructed;
• if an indirect refrigerating circuit is being used, the secondary circuits
shall be checked for the presence of refrigerant;
• marking to the equipment continues to be visible and legible, marking
and signs that are illegible shall be corrected;
• refrigeration pipe or components are installed in a position where they
are unlikely to be exposed to any substance which may corrode
refrigerant containing components, unless the components are
constructed of materials which are inherently resistant to being
corroded or are suitably protected against being so corroded.
9. Checks to electrical devices
Repair and maintenance to electrical components shall include initial
safety checks and component inspection procedures. If a fault exists that
could compromise safety, then no electrical supply shall be connected to
the circuit until it is satisfactorily dealt with. If the fault cannot be correct-
ed immediately but it is necessary to continue operation, and adequate
temporary solution shall be used. This shall be reported to the owner of
the equipment so all parties are advised.
Initial safety checks shall include:
• that capacitors are discharged: this shall be done in a safe manner to
avoid possibility of sparking
• that there no live electrical components and wiring are exposed while
charging, recovering or purging the system;
• that there is continuity of earth bonding.
10. Sealed electrical components shall be replaced
11. Intrinsically safe components must be replaced.
12. Cabling
Check that cabling will not be subject to wear, corrosion, excessive
pressure, vibration, sharp edges or any other adverse environmental
effects. The check shall also take into account the effects of aging or
continual vibration from sources such as compressors or fans.
13. Detection of Flammable Refrigerants
Under no circumstances shall potential sources of ignition be used in the
searching for or detection of refrigerant leaks. A halide torch (or any other
detector using a naked flame) shall not be used.
The following leak detection methods are deemed acceptable for
refrigerant systems. Electronic leak detectors may be used to detect
refrigerant leaks but, in the case of FLAMMABLE REFRIGERANTS,
the sensitivity may not be adequate, or may need re-calibration.
(Detection equipment shall be calibrated in a refrigerant-free area.)
Ensure that the detector is not a potential source of ignition and is suitable
for the refrigerant used. Leak detection equipment shall be set at a
percentage of the LFL of the refrigerant and shall be calibrated to the
refrigerant employed, and the appropriate percentage of gas (25%
maximum) is confirmed. Leak detection fluids are also suitable for use
with most refrigerants but the use of detergents containing chlorine shall
be avoided as the chlorine may react with the refrigerant and corrode the
copper pipe-work.
NOTE Examples of leak detection fluids are
• bubble method,
• fluorescent method agents.
If a leak is suspected, all naked flames shall be removed/extinguished.
If a leakage of refrigerant is found which requires brazing, all of the
refrigerant shall be recovered from the system, or isolated (by means of
shut off valves) in a part of the system remote from the leak. See the
following instructions for removal of refrigerant.
14. Removal and evacuation
When breaking into the refrigerant circuit to make repairs - or for any
other purpose conventional procedures shall be used. However, for
flammable refrigerants it is important that best practice be followed, since
flammability is a consideration.
The following procedure shall be adhered to:
• safely remove refrigerant following local and national regulations;
• evacuate;
• purge the circuit with inert gas (optional for A2L);
• evacuate (optional for A2L);
• continuously flush or purge with inert gas when using flame to open
circuit; and
• open the circuit
The refrigerant charge shall be recovered into the correct recovery
cylinders if venting is not allowed by local and national codes. For
appliances containing flammable refrigerants, the system shall be purged
with oxygen-free nitrogen to render the appliance safe for flammable
refrigerants. This process might need to be repeated several times.
Compressed air or oxygen shall not be used for purging
refrigerant systems.
For appliances containing flammable refrigerants, refrigerants purging
shall be achieved by breaking the vacuum in the system with oxygen-free
nitrogen and continuing to fill until the working pressure is achieved, then
venting to atmosphere, and finally pulling down to a vacuum (optional for
A2L). This process shall be repeated until no refrigerant is within the
system (optional for A2L). When the final oxygen-free nitrogen charge is
used, the system shall be vented down to atmospheric pressure to enable
work to take place.
The outlet for the vacuum pump shall not be close to any potential
ignition sources, and ventilation shall be available.
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