User's Manual

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Micropilot FMR50
28 V. 1, Rev. 6, 4-10-2012 Endress+Hauser
Overvoltage protection
If the measuring device is used for level measurement in flammable liquids which requires the use of
overvoltage protection according to DIN EN 60079-14, standard for test procedures 60060-1 (10 kA, pulse
8/20 ms), overvoltage protection has to be ensured by an integrated or external overvoltage protection
module.
Integrated overvoltage protection
An integrated overvoltage protection module is available for 2-wire HART as well as PROFIBUS PA and
FOUNDATION Fieldbus devices.
Product structure: Feature 610 "Accessory mounted", option NA "Overvoltage protection".
Technical data
Resistance per channel
2 * 0.5 W max
Threshold DC voltage 400 to 700 V
Threshold impulse voltage < 800 V
Capacitance at 1 MHz < 1.5 pF
Nominal arrest impulse voltage (8/20 ms)
10 kA
External overvoltage protection
HAW562 or HAW569 from Endress+Hauser are suited as external overvoltage protection.
For detailed information please refer to the following documents:
• HAW562: TI01012K
• HAW569: TI01013K