6
C6.2.15/0815/E
2.4 Dimensions
Compressor model
A ± 3.0
mm
B
mm
C ± 3.0
mm
D ± 3.0
mm
ZPD34K*E- PFZ/TFM
449.0
380.1
277.1
235.5
ZPD42K*E- PFZ/TFM
449.0
380.1
277.1
235.5
ZPD54K*E- PFZ/TFM
465.4
396.5
293.5
251.9
ZRD42K*E- PFJ/TFD
449.0
380.1
277.1
235.5
ZRD48K*E- PFZ/TFD
465.4
396.5
293.5
251.9
ZPD34K* to ZPD54K* ZPD61K* to ZPD91K* ZPD104K* & ZPD122K*
ZRD42K* & ZRD48K* ZRD61K* to ZRD81K*
ZRD94K*
(*)
& ZRD125K*
ZPD154K* & ZPD182K*
ZPD103K*, ZPD120K* & ZPD137K*
(*)
No sight glass
Figure 3: Compressor dimensions
2.5 Operation, design & performance
The Copeland Scroll Digital compressor is capable of modulating its capacity from 10% to 100%.
The compressor is supplied along
with an external solenoid valve. This “normally closed” (de-
energized) solenoid valve is a key component for achieving modulation. When the solenoid valve
is in its normally closed position, the compressor operates at full capacity. When the solenoid
valve is energized, the two scroll elements move apart axially. During the unloaded state, the
compressor motor continues running, but since the scrolls are separated, there is no
compression. During the “loaded state”, the compressor delivers 100% capacity and during the
“unloaded state”, the compressor delivers 0% capacity. A cycle consists of a “loaded state” and
an
“unloaded state”. By varying the time of “loaded state” and “unloaded state”, an average
capacity is obtained. For instance, in a 20-second cycle, the average capacity is 75%, if the
“loaded time” is 15 seconds and the “unloaded time” is 5 seconds.