Engineering manual - UniSAB III 1.10.8
202/346
001930 en 2021.06
8: Vi mode
70 to 97%
Only relevant for screw compressors with electrical slide control. See subsection
9: Mechanical zero
No
Yes
Mechanical zero must only be set to
Yes
if the compressor has a built-in spacer block and automatic Vi
regulation. This way the travel of the capacity slide is automatically reduced by the percentage (0-40%)
entered in
Manual zero
. Thus corrected capacity is calculated and shown correctly.
10: Manual zero
0 to 40%
For screw compressors without automatic zero point setting, it is possible to manually set a "zero point"
below which the compressor capacity slide is not allowed to fall during compressor operation.
If the compressor has a built-in spacer block and automatic Vi regulation,
Manual zero
is used to reduce
the travel of the capacity slide by the entered percentage. Thus corrected capacity is calculated and
shown correctly. The value [0-40%] to be entered in
Manual zero
must be of the following size:
See
Table 51: Maximum movement of capacity slide
.
For SAB 202, which has automatic zero point setting, the value 0% must be kept. See also
6: Mechani-
cal zero
.
For SAB 120, 151, 193, 233, 283, 355 the configuration of
Manual zero
is now made automatically when
Rotatune is selected. See subsection
6.4.1 Drive6: Rotatune
. The automatic configuration of
Manual
zero
may still be changed manually, but the setting will be overwritten after a restart.
11: Capacity zero
0 to 60% (default: 0%)
For screw compressors type SAB 193 H
→
355 H without VSD it is possible to set a "zero point" capacity
limit, below which the compressor slide capacity is not allowed to fall during normal compressor opera-
tion. This configuration point is fixed at the default value, and may only be changed by a Johnson Con-
trols supervisor. When the
Capacity zero
parameter is set to 0%, the
Capacity zero
function is not
active, meaning the
capacity zero
function is deactivated as default.
Note:
However, in software version 1.10.7, the
Capacity zero
parameter is default set to 60%, meaning
the
Capacity zero
function is activated.
12: Booster (screw compressors)
No
Yes
Yes
means that the oil pump will run continuously during compressor operation. This allows the capacity
slide to be moved at low pressure conditions.
Note:
SAB Mk 3, SAB HR, SAB 202, VMY Mk 3, SV/FV and GSV/SGC compressors are fitted with dif-
ferential pressure controlled oil pumps and do therefore not use this configuration point.
Manual zero =
Max. movement of capacity slide
Length of spacer block x 100
Summary of Contents for SABROE Unisab III Control
Page 1: ...UniSAB III control Version 1 10 8 Engineering manual EN...
Page 2: ......
Page 347: ......
