37MGHAQ: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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LEAK DETECTION SYSTEM installed. Unit must be powered
except for service. For the unit with refrigerant sensor, when the
refrigerant sensor detects refrigerant leakage, the indoor unit will
display a error code and emit a buzzing sound, the compressor of
outdoor unit will immediately stop, and the indoor fan will start
running. The service life of the refrigerant sensor is 15 years. When
the refrigerant sensor malfunctions, the indoor unit will display the
error code “FHCC”.
The refrigerant sensor can not be repaired and can only be replaced
by the manufacturer. It shall only be replaced with the sensor
specified by the manufacturer.
2. When a FLAMMABLE REFRIGERANT is used, the requirements
for installation space of appliance and/or ventilation requirements are
determined according to:
- the mass charge amount (M) used in the appliance,
- the installation location,
- the type of ventilation of the location or of the appliance.
- piping material, pipe routing, and installation shall include
protection from physical damage in operation and service, and be in
compliance with national and local codes and standards, such as
ASHRAE 15, IAPMO Uniform Mechanical Code, ICC International
Mechanical Code, or CSA B52. All field joints shall be accessible
for inspection prior to being covered or enclosed.
- that protection devices, piping, and fittings shall be protected as far
as possible against adverse environmental affects, for example, the
danger of water collecting and freezing in relief pipes or the
accumulation of dirt and debris;
- that piping in refrigeration systems shall be so designed and
installed to minimize the likelihood of hydraulic shock damaging the
system;
- that steel pipes and components shall be protected against
corrosion with a rustproof coating before applying any insulation;
- that precautions shall be taken to avoid excessive vibration or
pulsation;
- the minimum floor area of the room shall be mentioned in the form
of a table or a single figure without reference to a formula;
- after completion of field piping for split systems, the field pipe-
work shall be pressure tested with an inert gas and then vacuum
tested prior to refrigerant charging, according to the following
requirements:
a. The minimum test pressure for the low side of the system shall
be the low side design pressure and the minimum test pressure
for the high side of the system shall be the high side design
pressure, unless the high side of the system cannot be isolated
from the low side of the system in which case the entire system
shall be pressure tested to the low side design pressure.
b. The test pressure after removal of pressure source shall be
maintained for at least 1 h with no decrease of pressure
indicated by the test gauge, with test gauge resolution not
exceeding 5% of the test pressure.
c. During the evacuation test, after achieving a vacuum level
specified in the manual or less, the refrigeration system shall be
isolated from the vacuum pump and the pressure shall not rise
above 1500 microns within 10 min. The vacuum pressure level
shall be specified in the manual, and shall be the lessor of 500
microns or the value required for compliance with national and
local codes and standards, which may vary between residential,
commercial, and industrial buildings.
- field-made refrigerant joints indoors shall be tightness tested
according to the following requirements: The test method shall have
a sensitivity of 5 grams per year of refrigerant or better under a
pressure of at least 0.25 times the maximum allowable pressure. No
leak shall be detected.
3. Qualification of Workers
Any maintenance, service and repair operations must be required
qualification of the working personnel. Every working procedure
that affects safety means shall only be carried out by competent
persons that joined the training and achieved competence should be
documented by a certificate. The training of these procedures is
carried out by national training organizations or manufacturers that
are accredited to teach the relevant national competency standards
that may be set in legislation. All training shall follow the ANNEX
HH requirements of UL 60335-2-40 4th Edition.
Examples for such working procedures are:
• breaking into the refrigerating circuit;
• opening of sealed components;
• opening of ventilated enclosures.
Servicing Information
1. 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
following precautions shall be complied with prior to conducting
work on the system.
2. Work procedure
Works shall be undertaken under a controlled procedure so as to
minimize the risk of a flammable gas or vapor being present while
the work is being performed.
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. work in confined
spaces shall be avoided.
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 flammable atmospheres. Ensure that the leak detection
equipment being used is suitable for use with flammable
refrigerants, i.e. no sparking, adequately sealed or intrinsically safe.
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.
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