### Asset Description:
AHU: Air Handling Unit: A device used to condition and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system.

### Conditions:
- AHU Running
- SubType NOT OAU, RAS, RAU
- OAT > Supply Air Temperature AND Setpoint Temperature Not Reporting
- Outside Air Damper % < 90%
- Enthalpy < 26 IF Economizer Mode and Return Enthalpy Not Reporting
- OAT < (Return Air Temperature - 3 °F)

### How long the conditions were met:
Met for 2 Hours

What underlying factor, as presented in the options, could explain the current asset state?
A. PDU unit is overloaded
B. Controls on CRAC are set too low
C. Damper is commanded open greater than it needs to be - check the BMS logic
D. The condenser water pumps are flowing water through a chiller that is off


# Answer

Answer: C. Damper is commanded open greater than it needs to be - check the BMS logic

Guidance Rationale: 
The Air Handling Unit (AHU) is running, and the outside air
temperature (OAT) is greater than the supply air temperature, while the setpoint
temperature is not reporting. Additionally, the outside air damper is less than
90% open, and the enthalpy is below 26 BTU/lb in economizer mode, with return
enthalpy not reporting. Moreover, the OAT is less than the return air
temperature minus 3 °F, suggesting that cooler outdoor air is available, yet may
not be used optimally due to suboptimal damper control. These conditions have
persisted for 2 hours, implying that the damper may be commanded open more than
necessary, resulting in inefficient ventilation or energy use. 

This points to a potential issue in the BMS logic, where the damper is not being properly
modulated based on actual thermal needs.  Comparing this with the other options,
Option A (PDU unit is overloaded) is unlikely because it does not directly
relate to the AHU's airflow and temperature conditions. Option B (Controls on
CRAC are set too low) is also less likely as it pertains to a different system
(Computer Room Air Conditioner) and does not explain the specific AHU conditions
observed. Option D (The condenser water pumps are flowing water through a
chiller that is off) is irrelevant to the AHU's airflow and damper issues.
Therefore, the most likely explanation is: "Damper is commanded open greater
than it needs to be – check the BMS logic."