Construction and Operation
5 --- 17
-
If the air systems pressure rises to the upper switching point and the running period
has already expired, the compressor package is switched off after the run ---on period
has expired (2).
-
If the air systems pressure rises to the upper switching point before the running period
has expired then the pressure decay time of the previous switching cycle is taken as
the criterium for the selection of the operating mode:
-- If the pressure decay time t
p
decay
was longer than the period set for the idle/standstill
period, the compressor is switched to standstill after the run ---on period has ex-
pired (3).
-- If the pressure decay time t
p
decay
was shorter than the period set for the idle / stand-
still period, the idle mode is selected (4), that is, the inlet valve closes and the com-
pressor is vented with running motor. When the running period expires the com-
pressor package switches to standstill only after the run ---on period has also
expired (5).
5.6
VARIO Control
Functional description:
The idle period is automatically lengthened or shortened by the variable idle control in rela-
tion to the number of motor starts. The number of motor starts during the preceding hour
are measured.
A high switching frequency leads to longer idle periods.
A low switching frequency leads to shorter idle periods.
Summary of Contents for SM 8
Page 9: ...Technical Specification 1 6...
Page 16: ...Construction and Operation 5 13...
Page 17: ...Construction and Operation 5 14...
Page 54: ...Appendix 11 51 11 Appendix 11 1 Wiring Diagram...
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Page 74: ...SM 8 SM 11 A 08 B 07 C 14 D 11...
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