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• Maintenance-free Application The QVE1901U Flow Switch is used in HVAC installations to monitor the flow of fluids in hydraulic systems, especially in refrigeration, heat pump and heating installations (for example: for use with condensers, boilers, heat exchangers, and so on).
Technical Instructions QVE1901U Flow Switch Document Number 155-711 September 20, 2012 Mechanical Design Reed Contact (3) The device records the flow of monitored medium via a paddle system (1), which has a permanent magnet (2) attached at its upper end. A reed contact (3) is positioned Magnet (2) outside the flow above this magnet.
QVE1901U Flow Switch Technical Instructions Document Number 155-711 September 20, 2012 • On site: Engineering Notes – A T-junction with a female-threaded (1/2" NPT) fitting is required for 3/4” to 2” line sizes. – A 1-inch, female-threaded (1/2” NPT) welding socket is required for 3" to 8" line sizes.
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Technical Instructions QVE1901U Flow Switch Document Number 155-711 September 20, 2012 Line Size 3/4-inch to 8 inches (20 mm to 200 mm) Nut size 27 external thread 1/2-14 NPT Welding adapter with female thread 1/2-14 NPT, adapter length 1’’ Figure 4.
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QVE1901U Flow Switch Technical Instructions Document Number 155-711 September 20, 2012 Elbow Plug Connector EN 175301-803-A Figure 5. Figure 6. Figure 7. Figure 8. • Loosen the central screw M3×35 and disconnect the cable socket from the connector . See Figure 5. Pull the central screw out of the cable socket •...
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Technical Instructions QVE1901U Flow Switch Document Number 155-711 September 20, 2012 Adjust Switching The switching unit of the control switch enables two contact types: Unit 1. Make contact (normally open): RED arrow on the switching unit Standard Contact 2. Break contact (normally closed):...
QVE1901U Flow Switch Technical Instructions Document Number 155-711 September 20, 2012 Field of use Specifications Suitable media water and water/glycol mixture Functional data Piping diameter 3/4-inch to 8-inch (DN 20 to 200) Type of switch Reed contact Maximum contact voltage...