Greenheck Fan VSU Make-Up Air Unit with Direct-Fired Gas Heater 470654 - Manual (Page 24)

24 Model VSU Make-Up Air
®
Insufficient Airflow
Troubleshooting
Damper(s) not fully opened?
Adjust damper linkage(s), or replace faulty actuator(s).
Damper actuators may take a few minutes to open.
Filters dirty or clogged
Clean or replace filters.
Reference: Maintenance - Routine, Filters, pg. 31
Blower speed too low?
Adjust drives as needed.
Reference: Start-Up - Blower, Air Volume Measurement and Check, pg. 14
System static losses too high?
Reduce losses by improving ductwork.
Yes
Yes
Yes
Yes
No
No
No
No
No
Leaks in ductwork
Repair leaks.
Yes
Belt slipping
Replace or tighten belt.
Reference: Maintenance - Routine, V-Belt Drives, pg. 31
Yes
Everything is working properly,
consult factory.
Yes
Too Much Airflow
Blower speed too high?
Adjust drives as needed.
Reference: Start-Up - Blower, Air Volume Measurement and Check, pg. 14
Insufficient external
static pressure?
Increase external static pressure.
Filters not in place?
Install filters.
Yes
Yes
Yes
No
No
Everything is working properly,
consult factory.
No