Labconco 3970202 User Manual - page 50

45 

Chapter 8: Troubleshooting

PROBLEM 

CAUSE 

CORRECTIVE ACTION 

Airflow Monitor 

Malfunction 

(Continued) 

Wrong alarm set 

point. 

Airflow monitor was not properly 

adjusted.  Repeat calibration steps 

outlined in this manual in Chapter 6. 

 Constant 

audible 

alarm. 

Check airflow and calibration of 

airflow monitor. See Chapter 6. 

Continuous alarm. 

Check the downflow velocity of the 

enclosure as the airflow of the 

system may have changed.  If 

incorrect, adjust the speed control to 

increase downflow velocity.  The 

HEPA filter may have become 

loaded. If downflow velocity is 

correct, calibrate the airflow monitor 

outlined in this manual in Chapter 6. 

Monitor alarms; air 

way to airflow 

monitor sensor is 

blocked by insects, 

dust or debris. 

Lightly clean the airway with clean 

air.  Be careful not to touch sensitive 

electrical components. 

 Audible 

disable 

will not stay 

operational. 

An alarm condition must be 

continuously present before the 

audible alarm can be silenced.  If 

flow conditions fluctuate near the 

alarm set point, the airflow monitor 

will automatically reset it.  Action 

should be taken to bring the 

enclosure airflow into proper 

operating parameters or adjust the 

alarm set point lower.