Troubleshooting Guide - ILX Lightwave LDT-5412B User Manual

Troubleshooting Guide

This section lists some common problems and corrective actions. In the event that the
corrective action does not resolve the problem, please contact ILX Lightwave.
For a comprehensive list of frequently asked questions, see the ILX Lightwave website or
contact ILX Lightwave Customer Service (see Comments, Suggestions, and Problems on page
viii for contact information).
SYMPTOM
The instrument does not power up
SNS OPEN indicator stays illuminated
and OUTPUT won't turn on.
The I LIMIT indicator goes on and stays
on and the LDT-5412B can't control to
temperature.
The ACTUAL values oscillate around
the SET value.
March 2013
CORRECTIVE ACTION
Check the power cord to make sure that it is properly
connected and check the wall outlet by connecting to a
known operational device.
Check the SET RESISTOR switch on the rear panel. If it is
in the EXT position, there must be an external resistor
connected across pins 5 and 6 of OUTPUT connector. If the
intended use is for front panel setpoint control move the
switch to the INT position.
Check the thermistor connections to be sure they are not
open circuit and that the THERMISTOR MODE switch is in
the correct position for the thermistor used.
It is normal for the I LIMIT indicator to turn on when there is
a large difference between the setpoint and the sensed
temperature, but if the indicator stays on and the ACTUAL
value does not become closer to the SET value there may
be issues with your setup.
Check the I LIMIT adjustment knob by setting the display
mode to TE CURRENT and adjust the I LIMIT knob until the
indicator turns off or the rated current of the TE being used
is reached.
Turn off the output. If the actual value approaches the
setpoint faster than with the output on, it is likely that the TE
is wired backward. Reverse the polarity of the leads.
Adjust the setpoint to a value closer to the actual reading. If
the I LIMIT indication goes away it means that you have
exceeded the power capability of the LDT-5412B. Either use
a new setpoint, or contact an ILX Lightwave technical sales
representative to help you with your application.
Reduce the rear panel GAIN control by adjusting counter
clockwise.
16 LDT-5412B