Hitachi PMML0524 Instruction Manual page 4

Additional safety manual for R32 refrigerant air conditioner and heat pump according to IEC 60335-2-40:2018
2. Servicing
2-1. Service personnel
• Any person who is involved with working on or breaking into
a refrigerant circuit should hold a current valid certificate
from an industry-accredited assessment authority, which
authorizes their competence to handle refrigerants safely
in accordance with an industry recognized assessment
specification.
• Servicing shall only be performed as recommended 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.
• Servicing shall be performed only as recommended by the
manufacturer.
2-2. Checks to the area
• Prior to beginning work on systems containing flammable
refrigerants, safety checks are necessary to ensure that the
risk of ignition is minimized. For repair to the refrigerating
system, the precautions in 2-2 to 2-10 shall be complied with
prior to conducting work on the system.
2-3. Work procedure
• Work shall be undertaken under a controlled procedure so
as to minimize the risk of a flammable gas or vapour being
present while the work is being performed.
2-4. 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.
2-5. 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 flammable atmospheres.
• Ensure that the leak detection equipment being used is
suitable for use with flammable refrigerants, i.e. non sparking,
adequately sealed or intrinsically safe.
2-6. 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 powder or CO
2
charging area.
2-7. No ignition sources
• No person carrying out work in relation to a refrigeration
system which involves exposing any pipe work that contains
or has contained flammable refrigerant 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
flammable refrigerant can possibly be released to the
surrounding space.
2 PMML0524 rev.2 - 01/2021
CAUTION
fire extinguisher adjacent to the
2-7. No ignition sources
• 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.
2-8. 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.
2-9. 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 charge size 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 are constructed of materials which
are inherently resistant to being corroded or are suitably
protected against being so corroded.
2-10. 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 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.
• 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.
3. 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.