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-- 6.
ELECTRONIC CARD DESCRIPTION --
6.1 General Operation
In normal operation, the detected delivery pressure controls regulation of the compressor once the
compressor has been started by pushing the start button, or by a remote start command if enabled. The
controller will perform safety checks and start the compressor if no inhibiting conditions are detected.
If a start inhibiting condition exists the compressor will not enter the started condition and a start inhibit
message is displayed. If a run inhibiting condition exists the compressor will enter the started condition but a
main motor start is inhibited; the compressor will remain in the standby condition and a run inhibit message is
displayed. If a load request is present, in accordance with internal pressure settings or by remote command,
the main motor is started in a star/delta sequence. When running in delta configuration, after the star/delta
time (adjustable) has expired, the load delay time (adjustable) prevents loading for a period to allow motor
speed to stabilise. The load delay time can be set to one second if required. When the load delay time has
expired the load valve output is energised and the compressor will load. If the unload pressure setting is
reached, or a remote unload command is received, the load valve output is de-energised and the
compressor will run offload for the standby run on time (adjustable) before the main motor stops and the
compressor enters Standby mode. The compressor will load again if pressure falls below the load setting
before the standby run on time expires. If in Standby mode, a motor start sequence followed by the load
delay time is executed before loading.
In the event of a motor stop, initiated by a stop command or when entering standby mode, a blow down timer
(adjustable) is started. If a start request is made during the blow down time the compressor will enter standby
mode until the blow down time expires. If already in standby mode, and a load request is present, the
compressor will remain in standby mode until the blow down time has expired. For units with internal
pressure detection enabled, a minimum internal re-start pressure can also be set to prevent a motor start
sequence before internal pressure is vented. In the event internal pressure fails to fall below the set
minimum re-start pressure within two minutes after the set blow down time has expired, a blow down fault is
generated and the compressor will shutdown. After an unload event a re-load timer (adjustable) is initiated
that will prevent re-loading, this time can be adjusted to a minimum of one second if required. Normal
automated operation is ended by pushing the stop button, a remote stop command or in the event of a
shutdown fault.
When stopped manually, or by a remote command, the load value is de-energised and the main motor
allowed to run-on for the stop run on time (adjustable).
This time can be adjusted to a minimum of one second if required. Safety checks are made continuously, if
there is a condition detected that presents a hazardous or damaging situation an immediate stop is
performed and the reason displayed as a shutdown error message. If a warning condition is detected an
Alarm message is displayed and normal operation continues.
pressure
time
motor running
delivery pressure
unload pressure
START
AND
LOAD
UNLOAD
STOP
load pressure
motor run
motor stop
LOAD
STANDBY
Run-On Time
STOP
Run-On Time
LOAD
UNLOAD
