FMS-2000C
LIT-12013504
36
Conguring 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 dierent modes of occupation.
Otherwise there is only one air change rate setpoint available.
Conguring 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 congure the analog input type for ow, tap the Type arrow.
5. On the Type screen, scroll to Flow.
6. To conrm 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 conrm 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 conrm 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 conrm 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 dierential 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 conrm the settings, tap the Checkmark icon.