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To prevent a partial or f ull blockage caused by shavings, foreign bodies, etc at the injection port, a
f ilter dryer should be installed in the liquid line before the DTC valve inlet.
3.17 DTC valve installation
The valve bulb must be installed in the top cap to adequately control scroll temperatures. Therefore
please ensure that the coil spring is properly placed inside the compressor. The coil spring is required
f or proper installation. It is part of the standard compressor delivery but can also be ordered as a
spare part.
The YF*K1E-dedicated DTC valve is equipped with a brazing connection. The valve should be
brazed on the injection port on the side of the compressor housing. Due to the high heat development
during the brazing process, it is recommended to cover the D TC valve as well as the electrical box
plastics with a wet cloth.
For the built-in position, it is recommended that the valve be located perpendicular to the compressor
orientation. However, it will f unction properly in any orientation. The capillary tube connecting the
valve to the bulb should be positioned at least 13 mm away f rom the side of the scroll to avoid contact
during operation. The capillary tube f rom the bulb must not be in contact with the compressor top
when coming out of the thermo cap. The minimum distance between the insulated capillary tube and
the compressor top is 3 mm.
Figure 15: DTC valve overview
Figure 16: DTC valve assembly
The DTC valves are supplied with a thermo protection cap which is applied to the top of the
compressor.
Bef ore starting the compressor, ensure that there is liquid refrigerant in front of the DTC valve inlet.
Otherwise the valve could be damaged.
3.18 Suction line accumulator
Due to Copeland scroll's inherent ability to handle liquid refrigerant, for example in flooded start and
def rost cycle operation, an accumulator is not required in most systems.
To determine if a suction line accumulator is required, the system designer must check this with an
appropriate test scenario. See section 3.15 "Compressor oil return, oil balancing, floodback and
oil dilution tests".
If an accumulator is used, the oil-return orifice should be from 1 to 1.4 mm in diameter for all YF*K1E
models depending on compressor size and compressor floodback results. To protect this small orifice
f rom plugging with system debris a large-area protective screen no finer than 30 x 30 mesh (0.6 mm
openings) is required. Tests have shown that a small screen with a f ine mesh can easily become
plugged causing oil starvation to the compressor bearings. The size of the accumulator depends
upon the operating range of the system and the amount of sub -cooling and subsequent head
pressure allowed by the ref rigerant control. For the correct selection and size of the suction line
accumulator, refer to the manufacturer's specifications.
AGL_Ref_ST_YFK1E_EN_Rev01
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