Ohyama woozoo IPE-1221G, Руководство пользователя, Страница: 21 / 120

17
EN EN
Specialist’s anual
11
15
4
<0.152
Room area (m 2 )
0.225 0.304
Maximum charge (kg)
table a - Maximum charge (kg)
Prior to beginning work on systems containing
flammable refrigerants, safety checks are necessary
to ensure that the risk of ignition is minimised. For
repair to the refrigerating system, the following
precautions shall be complied with prior to conduct-
ing work on the system.
● Work procedure
Work shall be undertaken under a controlled
procedure so as to minimised the risk of a flammable
gas or vapour being present while the work is being
performed.
● General work area
All maintenance staff and others working in the local
area shall be instructed on the nature of work being
carried out. Work in confined spaces shall be
avoided. The area around the workspace shall be
sectioned off.Ensure that the conditions within the
area have been made safe by control of flammable
material.
● Checking for presence of refrigerant
The area shall be checked with an appropriate
refrigerant detector prior to and during work, to
ensure the technician is aware of potentially toxic or
flammable atmospheres. Ensure that the leak
detection equipment being used is suitable for use
with all applicable refrigerants, i.e. non-sparking,
adequately sealed or intrinsically safe.
● Presence of fire extinguisher
lf any hot work is to be conducted on the refrigera-
tion equipment or any associated parts, appropriate
fire extinguishing equipment shall be available to
hand. Have a dry powder or CO2 fire extinguisher
adjacent to the charging area.
● No ignition sources
No person carrying out work in relation to a
refrigeration 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.
● Ventilated area
Ensure that the area is in the open or that it is
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.
● 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. lf in doubt, consult the manufacturers'
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 circuit shall be checked for the
presence of refrigerant;
--- Marking to the equipment continues to be visible
and legible. Markings 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
Aptitude requirement for maintenance man
(repairs should be done only be specialists).
a.Any person who is involved with working on or
breaking into a refrigerant circuit should hold
acurrent valid certificate from an industry-accred-
ited assessment authority, which authorises their
competence to handle refrigerants safely in
accordance with an industry recognised
assessment specification.
b.Servicing shall only be performed as recommend -
ed by the equipment manufacturer. Maintenance
and repair requiring the assistance of other
skilled personnel shall be carried out under the
supervision of the person competent in the use of
flammable refrigerants.
Safety preparation work
The maximum refrigerant charge amount is shown
on the following table a.
(Note: Please refer to the nameplate for the
charging quantity of R290).
Specialist’s anual
are constructed of materials which are inherently
resistant to being corroded or are suitably protected
against being so corroded.
● Checks to electrical devices
Repair and maintenance to electrical components
shall include initial safety checks and component
inspection procedures. lf a fault exists that could
compromise safety, then no electrical supply shall be
connected to the circuit until it is satisfactorily dealt
with. lf the fault cannot be corrected immediately but it
is necessary to continue operation, an adequate
temporary solution shall be used. This shall be
reported to the owner of the equipment so all parties
are advised.
lnitial safety checks shall include:
---That capacitors are discharged: this shall be done
in a safe manner to avoid possibility of sparking;
--- That no live electrical components and wiring are
exposed while charging
,
recovering or purging the
system;
--- That there is continuity of earth bonding.
Repairs to sealed components
During repairs to sealed components, all electrical
supplies shall be disconnected from the equipment
being worked upon prior to any removal of sealed
covers, etc. lf it is absolutely necessary to have an
electrical supply to equipment during servicing, then a
permanently operating form of leak detection shall be
located at the most critical point to warn of a potential-
ly hazardous situation.
Particular attention shall be paid to the following to
ensure that by working on electrical components, the
casing is not altered in such a way that the level of
protection is affected. This shall include damage to
cables, excessive number of connections, terminals
not made to original specification, damage to seals,
incorrect fitting of glands, etc.
● Ensure that the apparatus is mounted securely.
● Ensure that seals or sealing materials have not
degraded to the point that they no longer serve the
purpose of preventing the ingress of flammable
atmospheres. Replacement parts shall be in
accordance with the manufacturer's specifications.
Note :
● The use of silicon sealant can inhibit the effective -
ness of some types of leak detection equipment.
Intrinsically safe components do not have to be
isolated prior to working on them.
Repair to intrinsically safe components
Do not apply any permanent inductive or capaci -
tance loads to the circuit without ensuring that this will
not exceed the permissible voltage and current per-
mitted for the equipment in use.
lntrinsically safe components are the only types that
can be worked on while live in the presenc of a
flammable atmosphere. The test apparatus shall be at
the correct rating.
Replace components only with parts spec the
manufacturer. Other parts may result in the ignition of
refrigerant in the atmosphere from a leak.
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 compres or
fans.
Detection of flammable refrigerants
Under no circumstances shall potential sour 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.
Leak detection methods
The following leak detection methods are deemed
acceptable for all refrigerant systems.
Electronic leak detectors may be used to detect
refrigrant leaks but, in the case of flammable refrigerants,
the sensitivity may not be adequate, or may need
re-calibration. (Detection equipment 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 appropri-
ate percentage of gas (25 % maximum) is confirmed.
Leak detection fluids are 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.
lf a leak is suspected, all naked flames shall be
removed extinguished.
lf 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. For
appliances containing flammable refrigerants, oxygen
free nitrogen (OFN) shall then be purged through the
system both before and during the brazing process.
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 is followed