Mitsubishi Electric R410A Service Handbook page 5

[4] Piping Work
Piping Work
To reduce the risk of injury, including frost
bites, that may result from being blasted
with refrigerant, use caution when operat-
ing the refrigerant service valve. If refriger-
ant leaks out and comes in contact with an
open flame, toxic gases may be generated.
To reduce the risk of refrigerant catching
fire and causing burns, remove the refriger-
ant gas and the residual refrigerant oil in the
pipes before heating them.
To reduce the risk of pipe damage, refriger-
ant leakage, and oxygen deprivation, use
pipes that meet the pipe thickness specifi-
cations, which vary by the type of refriger-
ant used, pipe diameter, and pipe material.
To reduce the risk of pipe burst or explo-
sion, evacuate the refrigerant circuit using a
vacuum pump, and do not purge the system
with refrigerant.
To reduce the risk of pipe bursting and ex-
plosion due to abnormal pressure rise, do
not allow any substances other than R410A
(such as air) to enter the refrigerant circuit.
[5] Wiring Work
Wiring Work
To reduce the risk of wire breakage, over-
heating, smoke, and fire, keep undue force
from being applied to the wires.
To reduce the risk of wire breakage, over-
heating, smoke, or fire, properly secure the
cables in place and provide adequate slack
in the cables so as not to stress the termi-
nals.
Do not use a mixture of solid wires and
stranded wires or wires of different sizes for
the power terminal block. If used, there is a
risk of smoke generation, ignition, and fire
due to a bad contact.
Tighten the screws of wiring terminals to
the specified torque. There is a risk of
smoke generation, ignition, and fire due to
screw looseness or a bad contact.
To reduce the risk of explosion and deterio-
ration of refrigerant oil caused by chloride,
do not use oxygen, flammable gas, or refrig-
erant that contains chloride as a pressuriz-
ing gas.
To prevent explosion, do not heat the unit
with refrigerant gas in the refrigerant circuit.
To reduce the risk of oxygen deprivation
and gas poisoning, check for gas leakage
and keep fire sources away.
Insulate pipe connections after completing
the air tightness test. Performing an air
tightness test with the pipe being insulated
may lead to failure to detect refrigerant leak-
age and cause oxygen deprivation.
To reduce the risk of pipe damage and re-
sultant refrigerant leakage and oxygen de-
privation, keep the field-installed pipes out
of contact with the edges of components.
To keep the ceiling and floor from getting
wet due to condensation, properly insulate
the pipes.
All electric work must be performed by a
qualified electrician according to the local
regulations, standards, and the instructions
detailed in the Installation Manual. Capacity
shortage to the power supply circuit or im-
proper installation may result in malfunc-
tion, electric shock, smoke, or fire.
To reduce the risk of electric shock, smoke,
or fire, install an inverter circuit breaker on
the power supply to each unit.
Use properly rated breakers and fuses (in-
verter circuit breaker, local switch <switch +
fuse>, no-fuse breaker). The use of a break-
er with a breaking capacity greater than the
specified capacity may cause electric
shock, malfunctions, smoke, or fire.
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