How to
Connecting an Air Velocity Probe to the MP-V Air Flow Sensor
You connect an air velocity probe installed in the duct inlet to the MP-V onboard air flow sensor (differential velocity pressure sensor) to measure the air flow in the VAV terminal unit.
The MP-V incorporates an integral actuator and the device is designed for over-the-shaft damper installation.
The MP-V can be used with dampers that are opened in clockwise (CW) position as well as dampers opened in counter-clockwise (CCW) position. You use WorkStation or the Commission mobile application to configure the MP-V actuator direction of rotation accordingly.
The MP-V is typically installed with the air flow sensor barbed fittings pointing down (orientation B in the figure below). The MP-V can also be installed with the barbed fittings pointing left (A), right (C), or up (D).
With a downward extension, the available area around the damper shaft must measure:
160 mm (6 inches) down from the lower edge of the shaft,
120 mm (4.5 inches) to the right,
45 mm (1.75 inches) to the left, and
45 mm (1.75 inches) above the shaft.
Ensure that the location allows enough clearance for servicing.
The MP-V actuator is designed to be installed over a 12.7 mm (0.5 inch) diameter round damper shaft with a minimum of 54 mm (2.125 inches) exposed damper shaft length.
When the damper shaft diameter is less than 12.7 mm (0.5 inch), an adapter is required. An adapter with part number AM-135 can be ordered from Schneider Electric to enable installation on a 9.5 mm (0.375 inches) diameter damper shaft.
The cutout section of the shaft adapter must be positioned such that the damper shaft mounting screws are tightened against the damper shaft and not the adapter cylinder.
When the exposed damper shaft length is less than 54 mm (2.125 inches) but greater than 22.2 mm (0.875 inch), you move the damper shaft mounting screws from the actuator collar to the alternative screw holes on the MP-V actuator.
The MP-V also has two mounting brackets, which allow you to choose the mounting bracket that best accomodates the available access space in the VAV mounting area. You position the anti-rotation clip in the desired mounting bracket.
The MP-V onboard air flow sensor is connected to an air velocity probe in the VAV box using two tubes. A dip in the tubing helps prevent moisture from entering the MP-V and damaging the air flow sensor. The dip should extend below the elevation of the barbed fittings. This applies to all MP-V orientations.
When operating in an unusually dusty environment, it is recommended to connect an in-line air filter (Schneider Electric part number 01-2100-272 or equivalent filter) on the high side pressure tube from the VAV box. The filter should be positioned close to the VAV box. The low flow of the sensor helps prevent most of the dust migration. The filter adds protection to help prevent dust from entering the velocity measurement tube in a dusty environment.
The recommendation to connect an air filter applies to MP-V hardware versions that have an air flow sensor of flow-through type. For more information, see Differences Between MP-V Hardware Versions .
The MP-V is delivered with terminal blocks installed on the device. Spare terminal blocks can be ordered separately using the part number SXWMPVCON10001.
The terminal blocks are removable. You can quickly and easily replace an MP-V because no terminal wiring is affected.
When the MP-V is powered up for the first time, the MP-V software automatically performs an actuator travel and damper position calibration. The calibration operation drives the damper actuator in the close direction and registers the position when the actuator encounters the stop. The software then drives the actuator in the open direction and registers the position when the stop is encountered. The software uses that information to scale the 0 to 100% span. Mechanical obstructions hindering the damper actuator rotation during the calibration process can adversely affect the calibration results and thus the VAV damper operation. In that case, after removing the mechanical obstruction, you can manually run a recalibration. For more information, see Configuring a Damper Command .
Initial calibration of actuator travel and damper position is performed automatically when the MP-V is powered up for the first time. If you subsequently press the manual override button, you must recalibrate the MP-V manually. For more information, see Configuring a Damper Command .
Connect tubing to the air velocity probe in the inlet section of the VAV box.
Note:A maximum length of 1.2 m (4 ft) FRPE polyethylene tubing with 6.4 mm (0.25 inches) outside diameter and 4.3 mm (0.17 inches) inside diameter is recommended for the typical plenum applications. The air flow sensor inputs on the VAV controller also supports flexible Tygon tubing (when plenum rating is not required), using tubes with size of 6.4 mm (0.25 inches) outside diameter and 4.8 mm (0.19 inches) inside diameter.
Connect the tube from the low pressure side of the air velocity probe to the barbed fitting labeled (Low) on the MP-V air flow sensor input.
Connect the tube from the high pressure side of the air velocity probe to the barbed fitting labeled (High) on the MP-V air flow sensor input.
Important:Ensure you connect the correct tube from the air velocity probe to the correct air flow sensor input on the VAV controller, to avoid incorrect control of the VAV terminal unit.
action_zoom_plus_stroke 
Create a tubing dip that extends at least 75 mm (3 inches) below the barbed fittings.
action_zoom_plus_stroke 
When operating in an unusually dusty environment, connect an in-line air filter (Schneider Electric part number 01-2100-272 or equivalent filter) on the high side pressure tube from the VAV box with the filter positioned close to the VAV box. The filter helps prevent dust from entering the velocity measurement tube.
Note:The recommendation to connect an air filter applies to MP-V hardware versions that have an air flow sensor of flow-through type. For more information, see Differences Between MP-V Hardware Versions .
action_zoom_plus_stroke 
MP-V Device Installation
Air Flow Sensor
Installing MP-V on a Damper that Rotates Counter-Clockwise (CCW) to Open
Installing MP-V on a Damper that Rotates Clockwise (CW) to Open
VAV Box Controls to Full Open State with Maximum Air Flow
Air Flow Rate Higher or Lower Than Expected
Differences Between MP-V Hardware Versions