4/Tests and Troubleshooting
1503-0151-000
5/26/0
4-11
Test Flow Valve
To test the flow valve the software starts off by closing the flow valve. It then opens
the flow valve in increments until the flow valve is completely open. At each of the
settings of the flow valve the A/D (Analog/Digital) channel for Flow DAC (Digital to
Analog Converter) Feedback and Flow Current Sense will be read. If the A/D for
the Flow DAC Feedback and Flow Current Sense are not within the correct toler-
ance the test fails.
A failure can be caused either by the drive circuit or the flow valve malfunction.
Check the drive circuit. Check the flow valve.
To check the drive circuit for proper voltage, set the flow control to output 120 liters
per minute. Unplug the connector from the microcontroller board and measure the
voltage between the pins, it should be approximately 3 volts. If the voltage is less
than 3 volts, measure the resistance between the leads at the unplugged flow valve
connector. A multimeter should read 3 ohms,
±
one percent. If the resistance is 3
ohms, the drive circuit is bad, replace the microcontroller board and test the flow
valve again. If the flow valve test fails again, replace the flow valve.
Summary of Contents for Aestiva 7900 SmartVent
Page 2: ...1503 0151 000 3 27 97 ...
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Page 12: ...Notes viii 1503 0151 000 3 27 97 ...
Page 18: ...1 Introduction 1 6 1503 0151 000 5 26 0 Notes ...
Page 44: ...2 Theory of Operation 2 26 1503 0151 000 3 27 97 Notes ...
Page 46: ...3 Post Service Checkout 3 2 1503 0151 000 5 26 0 Notes ...