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AGL_Ref_ST_YFK1E_EN_Rev01
3.8 Internal pressure relief valve
There is an internal pressure relief valve on YF*K1E compressors. It opens at a differential pressure
of 40.5 bar(g) ± 3 bar between high- and low-pressure sides. A high-pressure protection must be
provided by the system manufacturer/installer f or each system and according to EN 378-2, clause
6.2.6.2. The IPR valve is a safety device, not an HP switch. It is not designed for repeated operation
and there is no guarantee that it will reset correctly if it does have repeated operation.
3.9 Discharge check valve
YF*K1E compressors contain an internal check valve on the discharge connection. The discharge
check valve prevents the high-pressure discharge gas f rom f lowing rapidly back through the
compressor after shutdown.
NOTE: This check valve cannot be used with recycling pumpdown because it is not entirely
leak-proof.
3.10 Filter screens
CAUTION
Screen blocking! Compressor breakdown!
Use screens with at least
0.6 mm openings.
The use of filter screens finer than 30 x 30
mesh
(0.6 mm openings) anywhere in the system should
be avoided with these compressors. Field experience has shown that f iner mesh screens used to
protect thermal expansion valves, capillary tubes or accumulators can become temporarily or
permanently plugged with normal system debris and block the flow of either oil or refrigerant to the
compressor. Such blockage can result in compressor failure.
3.11 Mufflers
Gas f low through scroll compressors is continuous with relatively low pulsation. External mufflers
may not be required on Copeland scroll compressors. Due to system variability, individual tests
should be conducted by the system manufacturer to verify acceptable levels of sound and vibration.
If adequate attenuation is not achieved, use a muffler with a larger cross -sectional area to inlet area
ratio. A ratio of 20:1 to 30:1 is recommended. A hollow shell muffler will work q uite well. Locate the
muf fler at minimum 15 cm to maximum 45 cm from the compressor for the most effective operation.
The f arther the muffler is placed from the compressor within these ranges, the more effective. Choose
a muf f ler with a length of 10 to 15
cm.
3.12 Sound shell
For the selection of sound reduction material in A2L applications, attention shall be paid to the
electrostatic charge of the material, which could be a potential ignition source.
The standard Emerson sound shell material is not an ignition source f or A2L ref rigerants (R454C,
R455A and R454A).
NOTE: Please see Emerson spare parts software at
www.climate.emerson.com/en-gb/tools-
to check the available sound shell kits according to compressor model.
3.13 Insulation material
Insulation material is commonly used in a system to insulate the suction line, suction accumulator,
expansion valve bulb or discharge line thermostat. When choosing the insulation material f or A2L
applications, particular attention shall be paid to its non-electrostatic properties, as it could be a
potential ignition source.
