Johnson Controls FMS-2000C - Air Flow Input Configuration; Air Flow Measurement Parameters

FMS-2000C
LIT-12013504
36
Conguring the analog input to measure air ow
You can calculate and display the air change rate or display room cfm in AI-2, AI-3 and AI-4 with either a DP transmitter or ow sensor.
In AI-2 only, if you choose to calculate the air changes per hour, you can also select setpoints based on di󰀨erent modes of occupation.
Otherwise there is only one air change rate setpoint available.
Conguring the analog input type to measure air ow
1. On the home screen, tap the Settings icon to enter the Settings menu.
2. To view analog input settings, tap Analog I/O.
3. To nd the analog input you want to adjust, swipe left.
4. To congure the analog input type for ow, tap the Type arrow.
5. On the Type screen, scroll to Flow.
6. To conrm the settings, tap the Checkmark icon.
Specifying the sensor type to measure air ow
1. On the home screen, tap the Settings icon to enter the Settings menu.
2. To view analog input settings, tap Analog I/O.
3. To nd the analog input you want to adjust, swipe left.
4. Expand the Sensor Type and tap one of the following options:
• DP Transmitter
• Flow Sensor
5. To conrm the new settings, collapse Sensor Type.
Specifying the maximum input setting to measure air ow
If you are using a DP transmitter, set the maximum pressure input. If you are using a ow sensor, set the maximum ow input.
1. On the home screen, tap the Settings icon to enter the Settings menu.
2. To view analog input settings, tap Analog I/O.
3. To nd the analog input you want to adjust, swipe left.
4. To change the maximum pressure input, tap the Maximum Pressure Input arrow.
5. To conrm the settings, tap the Checkmark icon.
Specifying the minimum input setting to measure air ow
If you are using a DP transmitter, set the minimum pressure input. If you are using a ow sensor, set the minimum ow input.
1. On the home screen, tap the Settings icon to enter the Settings menu.
2. To view analog input settings, tap Analog I/O.
3. To nd the analog input you want to adjust, swipe left.
4. To change the minimum pressure input, tap the Minimum Pressure Input arrow.
5. To conrm the settings, tap the Checkmark icon.
Setting up the duct area to measure air ow
If you are using a DP transmitter, specify the cross-sectional duct area in square inches. This duct area converts a di󰀨erential pressure
or a velocity to a real-time volumetric ow, which can be used to calculate the air change rate. For round ducts, the cross-sectional area
can be determined by multiplying the square of the radius by pi. As an example, the cross-sectional area of a round 12 in. (304.8 mm)
duct, which has a radius of 6 in. (152.4 mm), is calculated as follows:
Area
round duct
= π * r
2
= 3.1416 * (6 in.)
2
= 113.09 in.
2
For rectangular ducts, the cross-sectional area can be determined by multiplying the length and width. As an example, the cross-
sectional area of a duct that measures 24 in. (609.6 mm) by 12 in. (304.8 mm) is calculated as follows:
Area
rectangular duct
= L * W = 24 in. * 12 in. = 288 in.
2
To specify the duct area for ow, complete the following steps:
1. On the home screen, tap the Settings icon to enter the Settings menu.
2. To view analog input settings, tap Analog I/O.
3. To nd the analog input you want to adjust, swipe left.
4. To specify the duct area, tap the Duct Area arrow and enter the result of your calculation.
5. To conrm the settings, tap the Checkmark icon.