Kobold DON-05, Руководство по эксплуатации

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DON-H
DON-H
01/0721
page 29
14. Troubleshooting
Oval gear flowmeters have two clearly distinct portions: one of which is
mechanical, wetted areas with the oval gears surrounded by a housing, and the
other is the electrical area, which includes the pulse output board.
Details of some key troubleshooting steps will now be provided. Please also refer
to the instructions on troubleshooting errors contained on the following page.
Step 1 - Check application, installation and set-up.
Carefully read the section on mechanical installation to ensure full knowledge of
all relevant installation and application factors which may affect the operation of
the counter. These include pulsation, trapped air or selecting the wrong counter,
including incorrect flow rate, temperature or pressure, or material incompatibility.
Refer to the section on electrical installation to ensure correct cabling.
Step 2 - Check for blockages.
For new and modified systems in particular, the most frequent cause of error or
sub-optimal counter operation is internal system or counter blockages due to
foreign particles, such as beads of condensate, sealing tape residues or mixtures
of deposits, rust, etc.
Step 3 - Guarantee flow rate.
Flow stopping or a flow rate declining below the usual limit may be attributable to
a blocked screen, flowmeter rotors which are stuck or damaged, a defective
pump, closed valves or an insufficient liquid level in the storage tank.
Step 4 - The oval gears in the counter must revolve.
This rotation is audible: try holding a screwdriver blade against the counter
housing and push the handle right against your earlobe. Test the counter as
required with flow switched on and off, to ensure you are familiar with the audible
sound of rotation.
Step 5 - Ensure that pulses are generated when liquids flow.
Here, a multimeter is often not fast enough to capture the pulse sequence of the
reed switch or the Hall Effect sensor. However, an oscilloscope will allow you to
observe the output pulse sequence. When testing the reed switch pulse, a pull-up
resistor must be installed between the single connection of the reed switch and
the supply voltage, while the other connection must be connected to the
reference potential of the measurement device (oscilloscope) (see electrical
installation).
Step 6 - Confirm device operation.
If a mounted electronic component is connected to the DON, check the functions
by simulating a pulse input. A reed switch pulse input can be simulated by a swift
and pulse-driven short-circuiting of the input terminals.