jkochan:
Its been bugging me why the problem all of a sudden showed up. Something triggered this!
“Within the last 60 days our cooling tower Lakewood TDS meter's operation became erratic.” “There has been no significant maintenance or changes to the system other than the usual monthly cleaning”
“No new equipment has been added and the system has been running trouble free for over six years.”
SOMETHING HAPPENED WITH IN THE LAST 60 DAYS.
I would suggest examining EVERYTHING that was done in the last 60 days. My guess is that you will find that the grounding of the conduits was disturbed. Check for structural modifications, cutting and welding, addition of _anything_ to the brackets that the conduit is mounted to, somebody cleaning up the area, new paint, apparently unrelated actions like paving, new siding, additional lighting, new signs, etc.
It could be that the grounding path was unintentional but it worked. Now that somebody ‘fixed it’ to the way it should be, and your problem showed up.
The other thing to check is the RF grounding of the motors themselves. Are the bodies of the motors isolated from the grounding system? Are the motors on vibration mounts? How about the output shaft couplings? Has there been any mechanical alignments, checks, or repairs with in the last 60 days?
For the system to work fine for six years and all of a sudden develop a problem in the last 60 days is a bit unusual. Poke around and try to figure out what changed.
LarryC
