Regarding the wiring change from four-wire to two-wire system?
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Vortex flow meter, four-wire terminals; one pair of signal wires comes from the DCS, along with 24V power supply. I would like to know how to wire it so that the signal transmission can proceed properly
This post was last edited by qugd on 2016-9-21 at 12:13. The power supply method for two-wire and four-wire instruments cannot be changed; one can only replace the instrument with one that uses the appropriate power supply method. This is because two-wire and four-wire instruments employ completely different designs in terms of power supply, signal acquisition, signal amplification, and output; it’s not as simple as just replacing a power supply module. The better vortex flowmeters available these days are all of the two-wire type; why is your organization still purchasing four-wire vortex flowmeters?
To install two wires, use the correct wiring method...
Four-wire instruments are generally powered by 220VAC, while two-wire instruments are powered by 24VDC.
I’ve seen quite a few 24vdc ones
That means another pair of wires is still needed; is it confirmed that it cannot be changed to a two-wire system?
It’s a pity that this flow meter is indeed a four-wire model, and it was newly purchased from Zhonghuan Tianyi. According to the manufacturer, it can be modified to operate in a two-wire configuration
Others asked the manufacturer and they said it was possible, but they didn’t ask in detail how to connect it in order to make it work
It is said to be too unreliable and untrustworthy. If it is written this way in the operation manual, then there must be corresponding illustrations or instructions in the manual. Perhaps the selection table offers options for two-wire and four-wire configurations, but once one option is chosen, the other cannot be easily implemented.
If you have power on site. On-site power supply can be used, and then a signal-converting safety barrier can be employed to convert the signals. It eliminates the hassle of setting out lines. If you want to use this single wire both for power supply and for signal transmission, it is impossible to do so. There must be another power source. Find a way to get this power supply; it doesn’t have to come from DCS.