Watlow CLS - Manual (Page 115)

Troubleshooting
CLS User’s Guide 107
Troubleshooting
The next few sections describe general troubleshooting for the CLS.
Later sections describe specific procedures, like checking an input,
changing the EPROM, and testing the controller.
First, Check your Installation
Please bear in mind that, even in stand-alone systems, the controller is
only part of your control system. Often, what appears to be a problem
with the CLS is really a problem with other equipment- so check these
things first:
• Controller is installed correctly. (See Installation for help.)
• Inputs — like thermocouples and RTDs — are installed correctly,
and they're working.
Second, Replace Unit
If you are certain that the controller is installed correctly, you can try
replacing the CLS with a spare CLS. If the spare unit works correctly,
then the problem is specific to the CLS you replaced.
WARNING
If the controller wasn't installed correctly--for instance, if
you have shorted sensor inputs to high voltage lines or a
transformer is shorted out--and you replace the CLS with a
spare unit, the spare unit will break, and you'll need to
send both units to Watlow Anafaze for repair. Therefore,
make sure you have checked the installation before replac-
ing the controller.
If you need to update the CLS Erasable Programmable Read-Only
Memory (EPROM), please refer to the third section in this chapter,
Changing the EPROM.
No Key Reset
If the instructions in this manual tell you to perform a “No Key Reset”,
please do the following:
1. Power down the unit.
2. Press and hold the No key on the front panel. Power up the unit.