Conair Thermolator TW-S User Manual page 79

C ont ro ller A l ar m s
When an alarm occurs, the Thermolator has detected a problem with the process. Without correction, the
TCU will not be able to produce process fluid of the correct temperature. Under certain conditions, an
alarm could lead to equipment damage or personal injury if it is not corrected.
• The controller displays an error code indicating the cause of the problem.
• If the optional alarm package is installed, the Fault strobe will illuminate and the audible alarm will
activate.
Alarm
2 2

H 22
Deviation Alarm –
Over Setpoint
The process temperature has
exceeded the allowable deviation
window for a certain amount of
time.
WARNING: Only qualified elec-
trical service personnel should
examine and correct problems
that require opening the unit's
electrical enclosure or checking
electrical current.
u ALARM LED flashes in con-
juction with an alternating
actual temperature display.
u Optional strobe, sounder, dry
contacts actuated.
u Pump continues to run nor-
mally.
u Heater continues to run
normally.
u Cooling valve continues to
run normally.
This alarm will automatically
reset when the problem is cor-
rected.
(Continued)
Possible Cause
Has water stopped flowing
throughout the unit or between
supply outlet and return inlet?
Did the cooling valve fail closed? Check the cooling valves.
Is the temperature difference
between the cooling water supply
and the setpoint too small?
Is the cooling valve under-sized
for the application?
Is the high process temperature
alarm too sensitive?
Is the high deviation temperature
alarm delay too short?
Is the initial deviation alarm
delay parameter too short?
Are the algorithm and PID pa-
rameters set correctly?
Solution
Verify that the unit is running and
that the pump is working.
Check for closed or defective
cooling or vent valves and plugged
lines. See Repairing Cooling
Valves.
Check for external closed valve on
the process fluid going to external
equipment.
Check for a plugged pipe.
See
Repairing Cooling Valves or the
Motorized Cooling Valve instruc-
tions.
The temperature difference should
be at least 25° F
{14° C} to achieve proper cool-
ing. Increase the process setpoint,
decrease the cooling water supply
temperature or increase the cooling
water supply pressure.
Check the cooling load (Btu/hr) for
which the valve was specified.
Modify the High Deviation Alarm
trigger point by increasing param-
eter H.
Modify the High Deviation Alarm
Delay by increasing parameter H.
Modify the "Startup Ignore Devia-
tion Delay" by increasing param-
eter .
Check the algorithm/PID param-
eters, including: t, Pb, E, n,
PbH, EH, nH, and Pbr.
(Continued)
Tr ou bl e s h oot i n g I 6-7