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『Endress Hauser Flow Meter Wiring Diagram and Grounding Rings Installation Instructions』Related information(v cone flow meter|rotary gas meter|gallon meter|gear meter|metal tube rotameter|glass tube rotameter|nutating disk meter|transit time ultrasonic flow meter|wedge flow meter|pd meters|hydraulic flow meter|ultrasonic water flow meter|water flow meter|air flow meter|magnetic water flow meter|oxygen flow meter|gas flow meter|argon flow meter|air velocity meter|gasoline flow meter|fuel flow meter|ultrasonic water meter|digital water meter|nitrogen flow meter|solid flow meter|Oxygen tank flow meter|digital water flow meter|diesel fuel flow meter|steam flow meter|02 flow meter|compressed air flow meter|oil flow meter|liquid flow meter)
Endress Hauser Flow Meter Wiring and Grounding Ring Installation
Quick Answer: For an Endress Hauser electromagnetic flow meter or a compatible Silver Automation Instruments unit, always connect power terminals and signal terminals exactly as shown on the wiring diagram inside the terminal cover. Install grounding rings on non-conductive pipes, lined pipes, and any pipe where the fluid has no direct metal contact to earth. A missing or poorly installed grounding ring often causes unstable flow readings.
Wire the Power Supply and Signal Outputs
Open the terminal cover and check the wiring diagram label first. Many Endress Hauser Promag models use separate terminal blocks for power and signal. The Silver Automation Instruments electromagnetic flow meter follows the same practical layout. Power input is usually 85 to 265 V AC or 24 V DC depending on your order code. Connect the live wire to terminal L and the neutral wire to terminal N for AC units. For DC units use plus and minus terminals. The PE terminal must be connected to earth. Do not switch the live and neutral wires because the meter can show false readings or get damaged.
Signal wiring covers 4 to 20 mA with HART, pulse output, frequency output, and RS485 Modbus. Use shielded twisted pair cable for the analog output and Modbus lines. In practice, most engineers skip this part but you should not. The shield must be earthed at only one end, normally at the control cabinet side. If you earth both ends, ground loops appear. Keep signal cables at least 30 cm away from VFD cables and motor cables. This one step reduces noise on many customer sites. For ATEX Zone 1 areas, use certified cable glands and follow the Ex wiring diagram strictly.
Grounding Ring Basics
Here is the thing. A grounding ring is a metal plate or ring installed between two flanges. It puts the fluid in contact with the meter ground system. You need grounding rings for plastic pipes, concrete pipes, rubber lined metal pipes, PTFE lined pipes, and any pipe with insulating inner coating. When the pipe is bare metal and the fluid touches the pipe wall, the pipe itself often acts as the ground path. But a Vietnam customer found unstable readings on a plastic pipe skid because no grounding rings were installed. Adding 316L stainless steel grounding rings fixed the flow signal in one hour.
Choose the grounding ring material by the fluid. Use 316L stainless steel for clean water, river water, seawater in desalination plants, and low concentration waste water. Use Hastelloy C276 for acids and aggressive chemical streams. Use titanium for high salinity seawater and brine. Use tantalum for very aggressive acids where other metals fail. The ring must be sized to your pipe schedule and flange standard such as DIN PN16, DIN PN40, ANSI 150, or ANSI 300.
Step by Step Grounding Ring Installation
Shut down the process and drain the pipe. Place the grounding ring between the two flange faces. Put the gasket on the opposite side of the ring from the meter body if the meter requires a separate gasket. Many users do not know this detail and end up with leakage. Insert the flange bolts and tighten them in a cross pattern. For a DN50 PN16 flange, torque values around 20 Nm to 25 Nm are typical b
Replacing an Endress Hauser Flow Meter with a Silver Automation Instruments Unit
If you plan to replace an Endress Hauser Promag unit with a Silver Automation Instruments electromagnetic flow meter, compare the terminal numbers before you wire anything. Most Promag models have analog output on terminals 26 and 27 but the numbering varies by generation. Our wiring diagram ships with every unit and uses plain labels like 4-20 mA, pulse, RS485 A and RS485 B. Field wiring becomes easier for plant electricians. Output options include 4 to 20 mA HART, pulse, frequency, and Modbus RTU. The display shows flow rate in m³/h or L/h with totalizer functions. Power supply options include 24 V DC, 220 V AC, and 110 V AC. Sizes cover DN15 up to DN2000 depending on the liner and electrode material.
Common Installation Mistakes
We have seen grounding rings installed backwards so the fluid never touches the metal surface. This defeats the purpose. Another common mistake is running signal cable in the same cable tray as VFD motor cables. The flow reading then jumps from 0 to a random value every time the pump starts. A paint manufacturer in Southeast Asia had a similar issue on a solvent line with lined pipe. The fix was rerouting the signal cable and adding a Hastelloy grounding ring. A third mistake is using a grounding ring for clean water but selecting the wrong material for a chemical stream. Hastelloy costs more but prevents early failure in acid service.
FAQ
Do I need grounding rings for a metal pipe?
Not always. Bare unlined metal pipes with conductive fluids often provide enough grounding. But if the pipe has an internal rubber or PTFE liner, install grounding rings. If the metal pipe is painted inside or has an insulating coating, install grounding rings as a standard practice.
Can I share the signal cable shield with the power earth?
No. Connect the signal shield to the instrument earth bar in the control cabinet. Connect the power earth to a separate PE terminal. Sharing them can create a ground loop and unstable readings.
What output signals match Endress Hauser wiring?
Most replacement projects use 4 to 20 mA HART plus pulse output. Silver Automation Instruments can supply 4 to 20 mA HART, pulse, frequency, and RS485 Modbus. Send us the existing Endress Hauser model number and we will help match the terminal layout.
What torque do I use for grounding ring bolts?
For DN50 PN16 flanges, a range of 20 Nm to 25 Nm is typical for carbon steel bolts with PTFE gaskets. For higher pressure classes like PN40 or ANSI 300, check the bolt grade. Always tighten in a cross pattern to avoid uneven gasket compression.
How do I get a quote for a replacement flow meter?
Send us your pipe size (DN), fluid type, conductivity in µS/cm, pressure in bar, temperature in °C, and flow range in m³/h or kg/h. Our team at Silver Automation Instruments will respond with a quote. Tel: +86-135-1213-1526. Whatsapp: 86-135-12131526. WeChat: +86 13512131526.