FRICK QUANTUM CONTROL PANEL
OPERATION
S90-010 O
Page 42
Leader's current reading falls below its “Capacity Con-
trol” setpoint plus the “Upper Dead Band” setpoint, the
Leader's start time delay will be reset to start counting
again. If a running compressor’s slide valve position
falls below 98%, the start time delay for starting the
next compressor will be reset to start counting again.
Next Compressor Stop Delay - The minimum time in
minutes that a running compressor must be at or below
the “Minimum Capacity to Stop Next Compressor” slide
valve position before the Follower Start output is de-
ener-gized to signal the next compressor to stop. This
is also the minimum time in minutes that the actual
capacity must be at or below the ”Capacity Control”
setpoint minus the “Lower Dead Band” setpoint
before the Leader that has already unloaded the
compressor to at or below its “Minimum Capacity
when Running” setpoint+ 1, will further unload
the compressor to below its “Minimum Slide
Valve Position to Start” setpoint, then stop.
This timer helps prevent compressors from cy-
cling on and off due to short sudden changes in
load within the system. If a running compressor’s Slide
Valve position rises above the “Minimum
Capacity to Stop Next Compressor” setpoint,
the stop timer for stopping the next
compressor will be reset to start counting again. And if
the actual capacity rises above the Leader's stop-
ping Capacity Control setting, the Leader's stop
time delay counter will be reset to start counting
again.
A toggle key is provided for compressor sequencing:
[Compressor Sequencing Activate] - Selects to use
compressor sequencing to control this compressor. The
delay timers that are present when sequence control is
activated won’t change by simply changing the set-
point. Sequence control must be deactivated and then
activated again.
[Compressor Sequencing De-Activate] - Selects to
not use compressor sequencing to control this com-
pressor. The Digital Board 2 outputs, 1 through 3 and
8, are turned off.
A toggle key is provided for control type:
[Control Type Leader] - Only one panel should be
s
elected as the Leader. The Leader compressor se-
quence controller attempts to maintain it’s capacity con-
trol setpoint by being the first compressor to start and
then loads and unloads in response to it’s Capacity
Control setpoints and furthermore will signal the next
panel(a Follower) to do likewise.
[Control Type Follower] - The Follower compressor
sequence controller is signaled from a previous panel
to load or unload and then uses it’s Capacity Control
setpoints to determine when to pulse the panel’s local
S
lide Valve load and Slide Valve unload outputs.
The Cycle Time setpoint determines the amount of time the
output is on and off, when in the proportional band. At the
completion of the cycle time the actual reading and neces-
sary response is reevaluated. If a 4 second period is se-
lected, then the following will result:
Proportional Distance
Actual Reading is Output Pulsed On Output Off
From Setpoint (seconds) (seconds)
004
1/4 1 3
1/2 2 2
3/4 3 1
140
Upper Cycle Time - This setpoint determines the
amount of time in seconds that the load output is on
and off, when in the upper proportional band. Refer to
the above description about cycle time.
Lower Cycle Time - This setpoint determines the
amount of time in seconds that the unload output is on
and off, when in the lower proportional band. Refer to
the above description about cycle time.
The following setpoints are required for each compressor
to be sequenced:
Minimum Capacity when Running - This is the slide
valve position a compressor will continuously load to,
when started. The compressor will not unload below
this setpoint during normal system operation. The last
compressor that was signaled to start will be the first
compressor to unload to it’s “Minimum Capacity when
Running” setpoint. Once the compressor has unloaded
to this capacity position, a previous compressor is then
allowed to unload. When the Slide Valve is above this
setpoint +1, the Follower sequence controller
energizes the Slide Valve > Minimum Capacity output.
Minimum Capacity to Stop Next Compressor - If this
compressor unloads to or below this setpoint and the
next compressor stop delay has timed out, then the
Follower Start output signal is de-energized to tell the
next com-pressor to stop. This compressor unloads to
this capac-ity position after the next compressor is
running at or below it’s “Minimum Capacity when
Running” setpoint.
Next Compressor Start Delay - The minimum time in
minutes that the actual capacity must be at or above
the starting capacity control setting before the Leader
sequence controller will start it’s compressor. Also, the
minimum time in minutes that a compressor must be at
or above 98% slide valve position before the
Follower Start output signal is energized to start the
next com-pressor and the Capacity Up output
signal is ener-gized to tell the next compressor to
load.. This timer helps prevent cycling compressors
on and off due to short sudden changes in load within
the system. If the
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