Hs.85: Capacity Control (Cr) And Start Unloading (Su) - Bitzer HS.8551 Instructions De Service

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Fig. 4: HS.85: ECO suction gas line with shut-off valve, pulsation
muffler and screw-in nozzle ①
Information
Notice for connecting external oil coolers, see
Manual SH-110.
Information
For other examples of pipe layout, see Manual
SH-110.
HS.95: ECO connection
The ECO connection is located on the top side of the
compressor housing; a swan neck pipe for protection
against oil migration is therefore not required. Guide
the line horizontally or downwards from the connection.
The SD42 muffler can be installed horizontally or vertic-
ally in the pipe (see also Operating Instructions
DB-400). The CM-SW-01 compressor module is in
charge of operating and controlling the separate liquid
injection (LI) (for further details, see Technical Informa-
tion ST-150).
Booster version HS.85
An external oil pump will be required in systems where
sufficient differential oil pressure cannot be built up dir-
ectly after compressor start. This applies, for example,
to large parallel compound systems with extremely low
condensing temperature or to boosters. For such ap-
plications, a special version without oil stop valve has
been developed for HS.85 compressors. The delivery
also includes a solenoid valve that has to be installed in
the oil line.
SB-110-3
Booster version HS.95 (currently not available)
Oil connection
HS.85: Pressure gauge connection on the oil valve for
maintenance
The pressure gauge connection on the oil valve for
maintenance is delivered with a screwing cap
(7/16-20 UNF, tightening torque max. 10 Nm). In case
of any modification, proceed very carefully.
4.4 HS.85: Capacity control (CR) and start unloading
(SU)
The HS.85 compressors are equipped by default with
"dual capacity control" (slide control). This allows both
infinite and 4-step regulation without any conversion of
the compressor. The only difference in the operating
mode is the activation of the solenoid valves.
Information
For detailed descriptions of capacity control,
start unloading and start unloading control, see
Manual SH-110.
CR2 (Y5)
CR4 (Y7)
CR3 (Y6)
CR1 (Y4)
Fig. 5: HS.85: Arrangement of the solenoid valves
CR
Start / Stop
CAP ⇑
CAP min 25% ① ⇓
CAP ⇔
Tab. 2: Infinite capacity control (CR) in the range 100% .. 25%
Y1 Y2 Y3 Y4
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