Mitsubishi Heavy Industries SRC20ZS-W Installation Instructions Manual Download

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'20 • SRF-DB-310

WARNING

RSA012A061B

WALL TYPE AIR-CONDITIONER

R32 REFRIGERANT USED

is leaked, together with an external ignition source, there is a

possibility of ignition.

There is information included in the user’s manual and/or

installation manual.

The user’s manual should be read carefully.

A service personnel should be handing this equipment with

reference to the installation manual.

• This safety precaution sheet is for R32 refrigerant. If you want to know the type of refrigerant in the unit, check the label attached to the outdoor unit.

• The precautionary items mentioned below are distinguished into two levels,

WARNING

and

CAUTION

WARNING

: Wrong installation would cause serious consequences such as injuries or death.

CAUTION

: Wrong installation might cause serious consequences depending on circumstances.

CAUTION

1. General

• That the installation of pipe-work shall be kept to a

minimum.

• That pipe-work shall be protected from physical

damage.

• That compliance with national gas regulations shall

be observed.

• That mechanical connections shall be accessible

for maintenance purposes.

• Keep any required ventilation openings clear of

obstruction.

• Servicing shall be performed only as recommended

by the manufacturer.

2. Unventilated areas

• The appliance shall be stored in a well-ventilated

area where the room size corresponds to the room

• The staff in servicing operations must hold the

4. Information on servicing

4.1 Checks to the area

• Prior to beginning work on systems containing

necessary to ensure that the risk of ignition is

minimised.

• For repair to the refrigerating system, 4.3 to 4.7

shall be completed prior to conducting work on the

system.

4.2 Work procedure

• Work shall be undertaken under a controlled

gas or vapour being present while the work is being

performed.

4.3 General work area

• All maintenance staff and others working in the

local area shall be instructed on the nature of work

being carried out.

•

• The area around the workspace shall be sectioned off.

• Ensure that the conditions within the area have

4.4 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

• 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.

4.5

• If any hot work is to be conducted on the

refrigeration equipment or any associated parts,

available to hand. Have a dry powder or CO

extinguisher adjacent to the charging area.

4.6 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

explosion.

• All possible ignition sources, including cigarette

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

• “No Smoking” signs shall be displayed.
4.7 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.

4.8 Checks to the refrigeration equipment

• Where electrical components are being changed,

• 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

– 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.

4.9 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 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 no live electrical components and wiring are

exposed while charging, recovering or purging

the system;

– that there is continuity of earth bonding.

5. 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.

• If 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

potentially 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

• 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

atmospheres.

• Replacement parts shall be in accordance with the

NOTE

The use of silicon sealant can inhibit the effectiveness

of some types of leak detection equipment.

Intrinsically safe components do not have to be

isolated prior to working on them.

• Strict compliance of the domestic laws must be

observed when disposing the appliance.

• Do not use means to accelerate the defrosting

process or to clean, other than those recommended

by the manufacturer.

• The appliance shall be stored in a room without

continuously operating ignition sources (for example:

operating electric heater.

• Do not pierce or burn.

• Be aware that refrigerants may not contain an

odour.

• The indoor unit shall be stored in a room that has a

minimum area of 4.0 m

CAUTION

6. Repair to intrinsically safe components

• Do not apply any permanent inductive or

capacitance loads to the circuit without ensuring
that this will not exceed the permissible voltage and
current permitted for the equipment in use.

• Intrinsically safe components are the only types that

can be worked on while live in the presence of a

• The test apparatus shall be at the correct rating.
•

the manufacturer.

• Other parts may result in the ignition of refrigerant

in the atmosphere from a leak.

7. 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.

• 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

9. Leak detection methods

• Electronic leak detectors may be used to detect

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

•

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.

•

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.

•

oxygen free nitrogen (OFN) shall then be purged
through the system both before and during the
brazing process.

10. Removal and evacuation

• When breaking into the refrigerant circuit to make

repairs – or for any other purpose – conventional

refrigerants it is important that best practice is

• The following procedure shall be adhered to:

– remove refrigerant;
– purge the circuit with inert gas;
– evacuate;
– purge again with inert gas;
– open the circuit by cutting or brazing.

• The refrigerant charge shall be recovered into the

correct recovery cylinders.

•

the unit safe.
This process may need to be repeated several
times.

• Compressed air or oxygen shall not be used for

purging refrigerant systems.

•

the working pressure is achieved, then venting to

This process shall be repeated until no refrigerant
is within the system.

•

shall be vented down to atmospheric pressure to
enable work to take place.
This operation is absolutely vital if brazing
operations on the pipe-work are to take place.

• Ensure that the outlet for the vacuum pump is not

close to any ignition sources and that ventilation is
available.

11. Charging procedures

• In addition to conventional charging procedures, the

following requirements shall be followed.
– Ensure that contamination of different refrigerants

does not occur when using charging equipment.
Hoses or lines shall be as short as possible to
minimise the amount of refrigerant contained in
them.

– Cylinders shall be kept upright.
– Ensure that the refrigeration system is earthed

prior to charging the system with refrigerant.

– Label the system when charging is complete (if

not already).

refrigeration system.

• Prior to recharging the system, it shall be pressure-

tested with the appropriate purging gas.

• The system shall be leak-tested on completion of

charging but prior to commissioning.

• A follow up leak test shall be carried out prior to

leaving the site.

12. Decommissioning

• Before carrying out this procedure, it is essential

that the technician is completely familiar with the
equipment and all its detail.

• It is recommended good practice that all

refrigerants are recovered safely.

• Prior to the task being carried out, an oil and

refrigerant sample shall be taken in case analysis is
required prior to re-use of reclaimed refrigerant.

• It is essential that electrical power is available

before the task is commenced.

a) Become familiar with the equipment and its

operation.

b) Isolate system electrically.
c) Before attempting the procedure ensure that:

– mechanical handling equipment is available, if

required, for handling refrigerant cylinders;

– all personal protective equipment is available and

being used correctly;

– the recovery process is supervised at all times by

a competent person;

– recovery equipment and cylinders conform to the

appropriate standards.

d) Pump down refrigerant system, if possible.
e) If a vacuum is not possible, make a manifold so

that refrigerant can be removed from various parts
of the system.

f) Make sure that cylinder is situated on the scales

before recovery takes place.

g) Start the recovery machine and operate in

accordance with manufacturer’s instructions.

volume liquid charge).

i) Do not exceed the maximum working pressure of

the cylinder, even temporarily.

and the process completed, make sure that the
cylinders and the equipment are removed from site
promptly and all isolation valves on the equipment
are closed off.

k) Recovered refrigerant shall not be charged into

another refrigeration system unless it has been
cleaned and checked.

13. Labelling

• Equipment shall be labelled stating that it has been

de-commissioned and emptied of refrigerant. The
label shall be dated and signed.

•

ensure that there are labels on the equipment

refrigerant.

14. Recovery

• When removing refrigerant from a system, either for

servicing or decommissioning, it is recommended
good practice that all refrigerants are removed
safely.

• When transferring refrigerant into cylinders, ensure

that only appropriate refrigerant recovery cylinders
are employed.

• Ensure that the correct number of cylinders for

holding the total system charge are available.

• All cylinders to be used are designated for

the recovered refrigerant and labelled for that
refrigerant (i.e. special cylinders for the recovery of
refrigerant).

• Cylinders shall be complete with pressure relief

valve and associated shut-off valves in good
working order.

• Empty recovery cylinders are evacuated and, if

possible, cooled before recovery occurs.

• The recovery equipment shall be in good working

order with a set of instructions concerning the
equipment that is at hand and shall be suitable
for the recovery of all appropriate refrigerants

• In addition, a set of calibrated weighing scales shall

be available and in good working order.

• Hoses shall be complete with leak-free disconnect

couplings and in good condition.

• Before using the recovery machine, check that it

is in satisfactory working order, has been properly
maintained and that any associated electrical
components are sealed to prevent ignition in the
event of a refrigerant release.
Consult manufacturer if in doubt.

• The recovered refrigerant shall be returned to the

refrigerant supplier in the correct recovery cylinder,
and the relevant Waste Transfer Note arranged.
Do not mix refrigerants in recovery units and
especially not in cylinders.

• If compressors or compressor oils are to be

removed, ensure that they have been evacuated to

refrigerant does not remain within the lubricant.

• The evacuation process shall be carried out prior to

returning the compressor to the suppliers.

• Only electric heating to the compressor body shall

be employed to accelerate this process.

• When oil is drained from a system, it shall be

carried out safely.

15. Other safety precautions

• A brazed, welded, or mechanical connection shall

be made before opening the valves to permit