Gree EJ51000061, Service Manual

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23
Rooftop Packaged
Service Manual
1.2.4 DUCTWORK
1) The Bottom duct openings are covered when they leave the factory ready to be used for a side supply /
side return application.
2) If a bottom supply / bottom return application is applied, you can simply remove the two covers from
the bottom of the unit and place them in the side supply / side return duct openings. What is stated above is
only applicable to the unit with the cooling capacity of 15 Ton or lower. As for all other units, the side supply air
outlet is factory defaulted. Meanwhile, the button supply air outlet is reserved; however, the seal plate should be
prepared by the user.
CAUTION:
The design and installation of air ducts must be in conformity with the relevant local engineering criteria.
Ductwork is to be constructed in a manner that limits restrictions and maintains suitable air velocity.
The air supply duct, the air intake duct must be covered with a layer of thermal insulation, so as to avoid
thermal leakage and condensation.
The air supply ducts and the air intake ducts shall be fixed by the prefabricated boards of the ceiling by
using iron supports. The joints of the ducts must be sealed by glue so as to avoid leakage.
The edge of the air intake duct must be at least 150mm away from the wall.
Silencing and shock absorption shall be considered in the design and installation of the air ducts.
Additionally, the noise source must be far away from where people stay. The air intake shall not be located
above the place where users stay (offices and rest places,etc.).
Do not terminate the air return duct in an area that can introduce toxic or objectionable fumes/odors into
the ductwork.
Each installation must include a return air filter. This filtering may be performed at the unit or externally
such as a return air filter grille.
Building condition and maintenance convenience should be taken into consideration when selecting the
installation method.
1.2.5 ADJUST THE TIGHTNESS OF THE BELT (ONLY 5 TON ABOVE)
The rotation of the fan is achieved by the transmission of the belt. The velocity and stability of the fan is
associated with the tightness of the belt and the tightness should be adjusted after a period of time.
For a new belt, the tightness should be adjusted for at least twice within 24 hours. After one week
running, the tightness of the belt should be adjusted again, we should routinely check it every 1-2 months; also
ensure the test results complying with the following table.
The adjustment of the tightness of the belt is shown in the following figure. Loosen screws fixing motor
on the base, move motor along the direction of arrow as shown in the picture, then fix the screw again.
The tightness level of belt is tested by densitometer as shown in the following figure, when
△
reaches
the deviation length, read the value on the meter, the value should be in the category specified in the following
table .
Section area
of the belt
Diameter of the
small wheel
(mm)
Diameter of
the big wheel
(mm)
The total length
of the belt
(mm)
Deviation
Length
(mm)
Tension(N)
Min. Max.
SPA
80 160 1250 6.93 18 26
100 160 1282 6.96 18 26