Mitsubishi Electric PUHY-HP72 Service Handbook page 5

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 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 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.
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.
To reduce the risk of current leakage, wire
breakage, smoke, or fire, keep the wiring
out of contact with the refrigerant pipes and
other parts, especially sharp edges.
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.
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.
To reduce the risk of current leakage, over-
heating, smoke, or fire, use properly rated
cables with adequate current carrying ca-
pacity.
Proper grounding must be provided by a li-
censed electrician.
Do not connect the grounding wire to a gas
pipe, water pipe, lightning rod, or telephone
wire. Improper grounding may result in
electric shock, smoke, fire, or malfunction
due to electrical noise interference.
iv