Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
145
# Name Description
30 MAX FLA%
or
MAX SLIDE %
or
MAX CAPACITY%
or
MAX VFD %
Indicates the maximum amp draw, slide %, digital scroll load%, or speed allowed. Usually set
to 100%, else compressors will load to the value of this Setpoint until all steps are on,
then the system will load to 100%.
‘Time (sec)’ field: If non-zero, then force individual compressors to stay at maximum capacity
when another compressor starts. This option is selected in in the ‘Keep Running Comp at
100% when starting next?’ box in the ‘Compressor Information’ panel under the MAG V8
screen.
‘SEC to Ignore Safety’ field (Fully Loaded Screw Compressor logic): If non-zero, turn on the
load solenoid every 5 min for 5 seconds when fully loaded. If zero, then do not turn on
solenoid for 5 seconds every 5 minutes.
‘SEC to Ignore Safety’ field (Holding Screw Compressor logic): If non-zero, turn on the load
solenoid every 5 min for 5 seconds when holding. If zero, then do not turn on solenoid for
5 seconds every 5 minutes.
31 MIN FLA%
or
MIN SLIDE %
or
MIN CAPACITY%
or
MIN VFD %
Value: Indicates the minimum amp draw, slide %, digital scroll load%, or speed allowed
(usually 40%). This is where the slide valve or VFD will be set when the compressor is
turned on. This % is a function of actual amp draw relative to the FLA.
‘Time (sec)’ field: If used, this forces a time delay before unloading all running compressors
before the next compressor is started. This time delay is specified in the ‘Unload
Compressor Before Starting Next’ box in the ‘Compressor Information’ panel under the
MAG V8 screen. Will Delay next compressor for this time after EVAP pump/valve is
opened.
32 MAX ADJUST % Indicates the maximum percentage change that can be made to the slide valve or VFD.
‘Time (sec)’ field: A zero indicates that the calculated FLA will be used, else the value in
Setpoint #31 will be used when starting the next compressor. This value is specified in
the ‘Wanted FLA starting next Compressor’ box in the ‘Compressor Information’ panel
under the MAG V8 screen.
33 MIN ADJUST % Indicates the minimum percentage change that can be made to the slide valve or the VFD.
For Fixed Step Compressors with adjustable speed AO’s when returning to 100% after
shutting down another compressor, this Setpoint will be the percent of adjustment along
with Setpoint #56 “PULSE DELAY” which is the time frame between capacity
adjustments.
34 SLIDE SENSITY This controls the sensitivity of the adjustment made to the Wanted Percentage (adjustments
are relative to the difference between the current control sensor and target). The larger
the value the larger the adjustment (usually 1).
35 AMP DB HI Used only with screw and centrifugal compressors. This value is the upper dead band limit of
the FLA. If the amps are within the dead band, the slide valve will not be moved.
If controlled by Slide Position, instead of FLA, this Setpoint will not be used.
36 AMP DB LO Used only with screw and centrifugal compressors. This value is the lower dead band limit of
the FLA. If the amps are within the dead band, the slide valve will not be moved.
If controlled by Slide Position, instead of FLA, this Setpoint will not be used.
37 LOAD PULSE Length of time to engage the slide valve load solenoid in tenths of a second (usually between
1 and 9).
‘Time (sec)’ field: If non-zero, use this value as a multiplier to increase the load pulse when
the compressor’s amp draw is more than three times the value of Setpoint #36 “AMP DB
LO”.
‘SEC to Ignore Safety’ field: If zero, then use delay between pulses. If non-zero, then no delay
between pulses when the compressor’s amp draw is more than twice the value of
Setpoint #36 “AMP DB LO” away from the wanted FLA.
38 UNLOAD PULSE Length of time to engage the slide valve unload solenoid in tenths of a second (usually
between 1 and 9).
Optional: If compressor type is Hanbell 3 solenoid and Time (SEC) cell of Setpoint #38, is not
zero DO NOT turn the unload solenoid ON (which is normal) when the compressor is in a
fast unload state, pumpdown unloading state or for the first 15 minutes after the
compressor is turned off.