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Pmag
- Installation
5.9 Grounding
The grounding of the instrument must be satisfied because the signal the instrument
measured is very weak, only a few milli-voltages, even at its full range. See figure 9
for the grounding position. There are two requirements for grounding:
1) The sensor and the fluid must be equipotential.
2) Special grounding fitting must be assembled when electromagnetic disturbance
is greater. Total section area of the wires for grounding shall be greater than 4mm
2
with multicore threads of copper. Grounding wire cannot be connected on electric
motor or common grounding's for all other equipment in case of the influence
occurred from any electric current leakage.
The resistance of grounding shall be less than 10 ohm. See figure 9.
The sensor must be assembled with grounding rings or flanges on its both sides, or a short pipe on which there is an
electrode for grounding when the sensor shall be installed on plastic pipeline or the pipeline has insulated liner.
5.10 Preparation for operation
Strictly check the installment and wirings before it gets into operation!
It shall be pointed out that the instrument, including the sensor and converter has been fully adjusted, calibrated
with actual flow, and inspected under strict measures. All shipped units are certified. No further adjustments
are required when put it into operation. Observing the contents in this manual, to check and analyze any
malfunction
The following steps are to be followed to get the instrument into operation.
1) Make sure that the sensor is completely filled with fluid.
2) Turn on the power supply. One minute late, the value displayed in the indicator will reach some amount, which
means the connections of wires are correct. If the flow direction is wrong, then change the flow direction on the
converter..
3) Zero verification. Shut off the valve tight in downstream first and then the valve in upstream, to let the medium in the
pipeline stops. The displayed value should be 0. The value displayed can be corrected at the converter if the value is
different than 0: ensure that no leaks.
Figure 9