Plc Control Alarm Conditions - Conair PCW-1.5 User Manual

P L C C o n t r o l A l a r m C o n d i t i o n s
Before an alarm can be reset with the acknowledge key, the alarm condition must
be cleared. To acknowledge an alarm is press and hold the alarm silence (#9) but-
ton for 3 seconds.
When the temperature falls below the Low Temperature cut out, the compressor
shuts off. The Alarm light illuminates and the PLC displays "Low Temperature
Cutout". The process or recirculation pump remains running until the Stop button
is pressed. For the single pump, this is the To Process temperature. For a dual
pump, see Evap Outlet Temp.
When the To Process Temperature increases to 95°F{35°C} the compressor shuts
off. The Alarm light illuminates and the PLC displays "High Temp Safety
(Temp>95°F)". The process pump remains running until the Stop button is pressed.
If the temperature rises above the setpoint a high temperature deviation occurs. The
degrees Fahrenheit deviation is a variable from 3 to 20, adjustable on a Setup
screen. If a high deviation is present the Alarm light illuminates and the PLC dis-
plays "High Temperature Deviation". The alarm can be cleared after the tempera-
ture drops below the high temperature deviation setpoint or the high deviation is
changed to a larger value and the alarm is acknowledged. Acknowledge the alarm
by pressing the Stop Chiller button. * Not recorded in alarm history.
If the flow switch (FS-1) detects a low flow condition, the compressor and process
pump will be shut down. The "alarm" light illuminates and the PLC indicates
"Flow Fault". The process pump will remain running until the Stop button is
pressed. For a dual pump, the Process Pump remains ON.
When the refrigerant suction pressure (PT-1) goes below 28 PSIG the compressor
will be shut off. The "alarm" light illuminates and the PLC indicates "Low
Suction Pressure" for the compressor on a single compressor system and compres-
sor 1 on a dual compressor system. The PLC will indicate "Low Suction Pressure
2" for compressor 2 on a dual compressor system. The process pump will remain
running until the Stop button is pressed. (Suction pressure when PTI goes below
0 psig, leads to sensor failure.)
Low Temperature Cutout
*requires manual reset
High Temp Safety
(Temp >95°F)
*requires manual reset
High Temperature Deviation
Flow Fault
Low Suction Pressure
*requires manual reset
Low Suction Pressure 2
*requires manual reset
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