D6.3.4/0715-0716/E
9
perfect starting even when the voltages amount to less than approximately 85% of the voltage
on the nameplate.
Unloaded start is not available for Copeland brand 2-stage compressors and K/L.
NOTE:
For more information please refer to Technical Information D7.10.2
“Starting
methods and unloaded start for semi-
hermetic compressors”.
2.6.4 Capacity control
For 3, 4, 6 and 8 cylinder compressors a mechanical capacity control is available. Be aware that
unloaded operation changes the application range of the compressor.
NOTE:
For more information please refer to Technical Information D7.21.1
“Semi-hermetic
compressors capacity control
”.
2.6.5 Demand Cooling
“Demand cooling”
,
as the term implies, means liquid refrigerant injection on demand.
If a low-temperature R22 installation is required, the following compressors can be equipped with
a Demand Cooling accessory kit:
2DL*
- 400
D4DF* - 1000
2DB*
- 500
D4DL* - 1500
3DA*
- 500
D4DT* - 2200
3DC*
- 750
D6DL* - 2700
3DS*
- 1000
D6DT* - 3000
* The fourth or fifth digit of the model designation
must be ≥ 3 for D4D & D6D and ≥ 4 for 3D.
2.6.6 Discharge Temperature Control valve (DTC)
The Discharge Temperature Control valve liquid injection system is a low cost and reliable
solution for the D3SC-750/X, D3SS-1000/X, D4SL/T, D6SL/T and D6SU compressors to obtain
lower evaporating temperatures within an extended operating envelope.
The afore-mentioned compressors are equipped with a plugged injection port on the side of the
compressor wall close to the base of the cylinder block. The injection port can be retro-fitted with
the DTC valve. The temperature sensing element with 12” NPT thread fits on the D4SL/T,
D6SL/T and D6SU compressor body close to the discharge shut-off valve.
Please note that:
DTC is needed only in systems with R22 refrigerant.
The valve can be obtained as an optional extra.
It is recommended to use an additional fan with the DTC valve for performance values as
shown in Copeland brand products Select software.
The D4SL/T, D6SL/T and D6SU compressors with DTC valve and fan operate with a voltage
tolerance of ± 5% over the complete operating envelope.
NOTE:
For more information please refer to Technical Information D7.19.1
“Assembling
the DTC valve for semi-hermet
ic R22 low temperature applications”.
2.6.7 Running gear lubrication
Air- or water-cooled compressors
Air- or water-cooled compressors that are filled with mineral oil have an oil centrifuge. The oil
supplied is drawn over a magnetic plug in order to separate even the smallest iron particles from
the oil.
Air- or water-cooled compressors that are lubricated with ester oil have an integral low-pressure
oil pump. These compressors, with pump and ester oil filling, are marked with “P” in compressor
nomenclature. An exception is the KSLP-200 which has an oil pump but is filled with mineral oil.
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