→ Table 15 — Zone Air Balance/Commissioning Table
DESCRIPTION | DEFAULT | POINT NAME |
Commissioning Mode | Dsable | CMODE |
Damper/Transducer Calibration | Dsable | CALIBRAT |
Maximum Cooling | Dsable | MAXCOOL |
Minimum Cooling | Dsable | MINCOOL |
Heating Override | Dsable | HEATOVER |
Fan Override | Dsable | FANOVER |
CFM Set Point | 0 cfm | COMCFM |
Actual Airflow | 0 cfm | AIRFLOW |
Primary Damper Position | 100 % | DMPPOS |
Measured Velocity Pressure | 0.000 in. wg | MVP |
Supply Air Temperature | 0.0 F | SAT |
Normal | CAL | |
Calibration Gain | 1.000 | CAL_GAIN |
Heating Override — This variable can be used to test the heat outputs. Enabling this variable will cause the heat to be modu- lated or staged to full heat until this point is disabled or the force released. Ducted reheat operation will be controlled so as not to exceed the configured maximum duct temperature. The
Heating Override: Display Range | Dsable/Enable |
Default Value | Dsable |
Network Access | Read /Write |
Airflow CFM Set Point — This variable displays the current airflow set point that the zone controller is controlling to. Dur- ing the calibration tests this value can be forced, which will change the set point configuration for the value being tested.
Airflow CFM |
|
|
Set Point: | Display Units | CFM |
| Display Range | 0 to 9999 (Limited by |
| velocity pressure transducer high alarm | |
| limit) |
|
| Default Value | 0 |
| Network Access | Read /Write |
Actual Airflow Display — This variable shows the actual air- flow being measured, based on the inlet size configured. Dur- ing the Maximum and Minimum Cooling Airflow calibration tests this value can be forced, which will correct the multiplier or offset used to calculate the airflow.
Actual Airflow: Display Units | CFM |
Display Range | 0 to 9999 (Limited by |
velocity pressure transducer high alarm | |
limit) |
|
Default Value | 0 |
Network Access | Read /Write |
Primary Damper Position — This variable displays the cur- rent damper position. During CFM Balancing, this variable is used to display the position of the damper. This value can be used to see if the damper is fully open and the system air is sufficient.
Primary Damper |
|
|
Position: | Display Units | % (open) |
| Display Range | 0 to 100 |
| Default Value | 100 |
| Network Access | Read Only |
Measured Velocity Pressure — This variable displays the measured velocity pressure, which is used to check accuracy during test and balancing of the terminal. If the pressure appears to be much different than that measured with a Magna- helic gage, the transducer can be forced to recalibrate its zero by enabling the Damper/Transducer Calibration.
Measured Velocity |
|
|
Pressure: | Display Units | in. wg |
Display Range 0.000 to 2.000 (Limited by velocity pressure transducer high alarm limit)
Default Value | 0.000 |
Network Access | Read Only |
|
| |
Temperature: | Display Units | F (C) |
| Display Range | |
| Default Value | 0.0 |
| Network Access | Read /Write |
Normal/Alarm | |
Default Value | Normal |
Network Access | Read Only |
Calibration Gain — Air terminal testing by industry standards is done with straight duct, upstream of the terminal. Since most applications are not installed in this manner, the actual airflow from the terminal, at balancing, may not equal the reading from the zone controller.
The Calibration Gain is used for making fine tuning adjust- ments to the airflow calculation. This number is calculated au- tomatically by the zone controller after input to the air balance maintenance screen. The Calibration Gain can also be entered manually in the service configuration CONFIG screen.
A number of .95 entered into the Calibration Gain variable will cause the maximum airflow to be reduced to 95% of the calculated value. A number of 1.05 would cause readings to become 5% higher. The Calibration Gain is adjusted on the Air Balance maintenance screen when performing the Maximum Airflow Calibration and will have the greatest affect on the air- flow at maximum CFM.
After performing the air balance procedure using the air bal- ance maintenance screen, it is recommended to upload and save the Airflow Configuration, Calibration Gain, and Offset settings.
Calibration Gain: Display Range | 0.000 to 9.999 |
Default Value | 1.000 |
Network Access | Read Only |
501 | 48 |