Frick QUANTUM - Control Setup

FRICK QUANTUM CONTROL PANEL
OPERATION
S90-010 O
Page 17
The following is a list of all the different Capacity Control
setpoint screens:
• Suction Pressure Mode 1
• Suction Pressure Mode 2
• Process Temperature Mode 1
• Process Temperature Mode 2
• Discharge Pressure Mode 1
• Discharge Pressure Mode 2
• Discharge Temperature Mode 1
• Discharge Temperature Mode 2
Following is an example of a Capacity Control setpoint screen:
The following setpoints are required for each of the Capac-
ity Control setpoint screens:
Capacity Control - This setpoint is used to control the
loading and unloading of the compressor when the
Slide Valve Position is in the Automatic (AUTO) mode.
NOTE: The Process Temperature reading is used for
Capacity Control when Discharge Temperature Capac-
ity Control is used.
The Proportional Band setpoint determines a range of Ca-
pacity Control values where pulsed output is used. Beyond
the proportional band the output is continuously energized.
The length of time the output will be pulsed on is propor-
tional to the distance the actual reading is from the Capac-
ity Control setpoint. The further the distance from setpoint,
the longer the output is pulsed on and the shorter the output
is off. The closer the distance to setpoint, the shorter the
output is pulsed on and the longer the output is off. If the
actual reading is midpoint from setpoint, the output is on
and off an equal amount of time.
Upper Proportional Band - A band, measured in the
units of the Capacity Control setpoint, above the upper
dead band, where proportional load control is used. If
the actual reading rises into this proportional band, the
load output will be pulsed as explained above in the
description about proportional band.
Lower Proportional Band - A band, measured in the
units of the Capacity Control setpoint, below the lower
dead band, where proportional unload control is used.
If the actual reading falls into this proportional band,
the unload output will be pulsed as explained above in
the description about proportional band.
Upper Dead Band - A band, measured in the units of
the Capacity Control setpoint, above the setpoint at
which the compressor will neither load nor unload.
Lower Dead Band - A band, measured in the units of
the Capacity Control setpoint, below the setpoint at
which the compressor will neither load nor unload.
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 four second period is
selected, then the following will result:
Proportional
Distance
Actual Reading is Output Pulsed Output Off
From Setpoint On (Seconds) (Seconds)
004
1/4 1 3
1/2 2 2
3/4 3 1
140