One of the two exhaust fans dedicated to the acid benches tripped off yesterday due to excessive heat in one of the variable frequency drives.
The system did not go down completely but one fan is unable to maintain the exhaust plenum set point, hence the bench alarms.
This should be considered and unforeseen equipment failure.
The trouble fan VFD was reset, is running, and is maintaining set point.
We are in the process of ascertaining the cause of the trip and should have an answer for you before noon.
As of now the wet process rooms will be tagged out until we get the “all clear”. We will keep you updated.
NOTE: This is a reminder to always pay attention to the hood alarms and/or any warning signs and to stop your process ASAP. Luckily the users knew what to do and no one was hurt.