Amphenol Kaye CTR-40, User Manual, Page: 81 / 84

70
12 Troubleshooting
The displayed process temperature
is in error and the controller re-
mains in the cooling or the heating
state at any set-point value
Possible causes may be either a faulty control probe or erroneous data in
memory.
• The probe may be disconnected, burned out, or shorted. The probe is lo-
cated inside the stirrer motor cover.
• Check that the probe is connected properly. The probe may be checked
with an ohmmeter to see if it is open or shorted. The probe is a plati-
num 4-wire Din 43760 type. The resistance should read 0.2 to 2.0 ohms
between pins 1 and 2 on the probe connector and 0.2 to 2.0 ohms be-
tween pins 3 and 4. It should read 100 to 300 ohms between pins 1 and
4 depending on the temperature. If the probe appears to be defective,
contact Amphenol Advanced Sensors Customer Service for assistance.
• If the problem is not the probe, erroneous data in memory may be the
cause. Re-initialize the memory as discussed in the problem ‘The display
flashes “cutout” and an incorrect process temperature’. If the problem
remains, the cause may be a defective electronic component, contact
Amphenol Advanced Sensors Customer Service for assistance.
The controller controls or attempts
to control at an inaccurate
temperature
The controller operates normally except when controlling at a specified
set-point. At this set-point, the temperature displayed does not agree
with the temperature measured by the user’s reference thermometer to
within the specified accuracy. This problem may be caused by an actual
difference in temperature between the points where the control probe
and thermometer probe measure temperature, by erroneous bath cali-
bration parameters, or by a damaged control probe.
• Check that the bath has an adequate amount of fluid in the tank and
that the stirrer is operating properly.
• Check that the thermometer probe and control probe are both fully in-
serted into the bath to minimize temperature gradient errors.
• Check that the calibration parameters are all correct according to the
Report of Test. If not, re-program the constants. The memory backup
battery may be weak causing errors in data as described in the prob-
lem: ‘The display flashes “cutout” and an incorrect process temperature’.
• Check that the control probe has not been struck, bent, or damaged. If
the cause of the problem remains unknown, contact Amphenol
Advanced Sensors Customer Ser- vice for assistance.
The controller shows that the out-
put power is steady but the process
temperature is unstable
Possible causes are an improper proportional band setting or the fluid
being used.
• If the bath temperature does not achieve the expected degree of stabil-
ity when measured using a thermometer, try adjusting the proportional
band to a narrower width as discussed in Section 8.9, Proportional
Band.
• Check to ensure the fluid has not deteriorated or is not too thick.