Hitachi FSG Series, Technical Catalogue

Page: 326 / 424

14
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DRAIN PIPING
14.1 GENERAL
&
CAUTION:
– Do not create an upper-slope or rise for the drain
piping, since drain water will flow back to the unit and
leakage to the room will occur when the unit operation
is stopped.
– Do not connect the drain pipe with sanitary or sewage
piping or any other drainage piping.
– When the common drain piping is connected with
other indoor units, the connected position of each
indoor unit must be higher than the common piping.
The pipe size of the common drain pipe must be large
enough according to the unit size and number of unit.
– Drain piping will require insulating if the drain is
installed in a location where condensation forming on
the outside of drain pipe may drop and cause damage.
The insulation for the drain pipe must be selected to
insure vapor sealing and prevent condensation
forming.
– Drain trap should be installed next to indoor unit. This
trap must be designed to good practice and be
checked with water (charged) and tested for correct
flow.
Do not tie or clamp the drain pipe and refrigerant pipe
together.
?
NOTE:
Install drainage in accordance with national and local
codes.
After performing drain piping work and electrical wiring,
check to ensure that water flows smoothly as in the
following procedure:
n
Checking Unit without Drain-up Mechanism
– Pour approximately 1.8 liters of water into the drain
pan.
– Check to ensure that the water flows smoothly or
whether no water leakage occurs. When water cannot
be found at the end of the drain piping, pour another
approximately 1.8 liters of water into the drain pan.
n
Checking with Drain-Up Mechanism and Float
Switch
– Switch ON the power supply.
– Pour approximately 1.8 liters of water into the drain
pan, then float switch up and drain pump start working
automatically.
– Check to ensure that the water flows smoothly or
whether no water leakage occurs. When water cannot
be found at the end of the drain piping, pour another
approximately 1.8 liters of water into the drain pan.
– Switch OFF the power supply after.
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NOTE:
Pay attention to the thickness of the insulation when
the left side piping is performed. If it is too thick,
piping can not be installed in the unit.
Common Drain Piping
1/25~1/100 Down Slope
Drain Piping connection
CORRECT
INCORRECT
Incorrect:
Upward Slpoe
Incorrect: Rising Part