Troubleshooting – Airflow
The Test and Balance Report (TAB) is utilized to determine whether the appropriate amount of outdoor air and exhaust air is being supplied and removed from a building, respectively. There are no set rules on what information must be included in a TAB report. As such, if a TAB report indicates that the airflow on a unit is low, prior to contacting the factory, please determine the following information:
Unit #1 | Unit #2 | Unit #3 | Unit #4 |
Model Number
Serial Number
Nameplate Information
Voltage
Hertz
Phase
Outdoor Air Fan Amps
Outdoor Air Fan Horsepower
Design Airflow
Outdoor Air
Measured Airflow
Outdoor Air
Measured Data
Blower Rotation
Outdoor Air Fan RPM
Outdoor Air Fan Amp Draw
Airflow problems can often be tied back to improper ductwork installation. Be sure to install ductwork in accordance with SMACNA and AMCA guidelines.
Troubleshooting – Unit
Symptom | Possible Cause | Corrective Action |
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| Blown fuse or open circuit breaker. | Replace fuse or reset circuit breaker and check amps. |
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| Defective motor or capacitor. | Replace. |
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Blower fails to | Motor starter overloaded. | Reset starter and check amps. |
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operate | Electrical. | Check for On/Off switches. Check for correct supply |
| voltage. | |
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| Drive. | Check for broken or loose belts. Tighten loose |
| pulleys. | |
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| Shorten wiring run to mechanical room or install a |
| Control power (24 VAC) wiring run is too long | relay which will turn unit on/off. Consult Factory for |
Motor starters | (resistance should not exceed 0.75 ohms). | relay information. Increase wire gauge size so that |
| resistance is .075 ohms or less. | |
“chatter” or |
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Incoming supply power is less than anticipated. |
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do not pull in | Need to increase supply power or use a special | |
| Voltage supplied to starter coil must be within | |
| control transformer which is sized for the actual | |
| +10% / | |
| supply power. | |
| coil. | |
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Always have a completed Pre
Model
