5
English
REFRIGERANT PIPING WORK
5.
〈
Observe the requirements listed below for refrigerant
piping sizes.
〉
Liquid
Gas
12 · 18 type
2/8 in.
4/8 in.
24 · 30 · 36 ·
42 · 48 · 54 type
3/8 in.
5/8 in.
〈
Execute heat insulation work completely on both sides of
the gas piping and the liquid piping. Otherwise, a water
leakage can result sometimes.
Use insulation that can withstand temperatures of at least
250°F. Reinforce the insulation on the refrigerant piping
according to the installation environment. If the tempera-
ture or humidity in the product installation location might
reach 86°F or 80%, respectively. Condensation may form
on the surface of the insulation.
〉
CAUTION
Follow the points at below.
Use a tube cutter and fl are suitable for the type of refriger-
•
ant.
To prevent dust, moisture or other foreign matter from infi l-
•
trating the piping, either pinch the end or cover it with tape.
Do not allow anything other than the designated refrigerant
•
to get mixed into the refrigerant circuit, such as air, etc. If
any refrigerant gas leaks while working on the unit, ventilate
the room thoroughly right away.
Cut off the spin closure.
(1)
The outdoor unit is charged with refrigerant.
•
This coil is shipped under 150 P.S.I.G. pressure.
•
Carry out the following work carefully giving caution to
blowout of high pressure gas.
(Work detail)
Cut off the spin closure with a tube cutter.
(Both liquid line and gas line)
Cut with a pipe cutter
Connect the piping.
(2)
Remove the front panels (upper) (lower).
1.
Slide the front panel (lower) along the fi eld piping until it
2.
is far enough away that it will not be affected by heat
from brazing, as shown in the diagram below.
Braze up to the fi eld piping fi tting port.
3.
Close the front panels (upper) (lower) once heat from
4.
the brazed areas has dissipated.
Field piping fitting port (brazed)
Field piping
After the work is fi nished, make sure to check that
(3)
there is no gas leak.
After checking for gas leaks, be sure to insulate the
(4)
pipe connections referring to below.
Do not leave a gap
Gas piping
Pipe heat insulation
material
Liquid piping
Main
unit
CAUTION
Be sure to insulate any fi eld piping all the way to the piping
connection inside the unit. Any exposed piping may cause
condensation or burns if touched.
When brazing the refrigerant piping, perform nitrogen re-
•
placement fi rst, or perform the brazing while feeding nitro-
gen into the refrigerant piping. (
see diagram below
)
Refrigerant piping
Part to be brazed
Taping
Pressure-reducing valve
hands
valve
Nitrogen
Nitrogen
CAUTION
When brazing a pipe while feeding nitrogen inside the pipe,
•
make sure to set the nitrogen pressure to 29 psi or less
using the pressure reducing valve.
(This pressure is such that breeze is blown to your cheek.)
DANGER
Use of oxygen could result in an explosion resulting in
•
serious injury or death. Only use nitrogen gas.
Refrigerant gas may produce toxic gas if it comes in contact
•
with fi re such as from a fan heater, stove or cooking device.
Exposure to this gas could cause severe injury or death.
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6/18/2009 2:01:15 PM
6/18/2009 2:01:15 PM
