Endress+Hauser Micropilot FMR56 - Overvoltage Protection

Micropilot FMR56, FMR57
30 Endress+Hauser
HART
• A normal device cable suffices if only the analog signal is used.
• A shielded cable is recommended if using the HART protocol. Observe grounding concept of the
plant.
• For 4-wire devices: Standard device cable is sufficient for the power line.
PROFIBUS
Use a twisted, screened two-wire cable, preferably cable type A.
For further information on the cable specifications, see Operating Instructions BA00034S
"PROFIBUS DP/PA: Guidelines for planning and commissioning", PNO Guideline 2.092
"PROFIBUS PA User and Installation Guideline" and IEC 61158-2 (MBP).
FOUNDATION Fieldbus
Endress+Hauser recommends using twisted, shielded two-wire cables.
For further information on the cable specifications, see Operating Instructions BA00013S
"FOUNDATION Fieldbus Overview", FOUNDATION Fieldbus Guideline and IEC 61158-2 (MBP).
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 μs), an overvoltage protection module has to be
installed.
Integrated overvoltage protection module
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 Ω 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 μs) 10 kA
External overvoltage protection module
HAW562 or HAW569 from Endress+Hauser are suited as external overvoltage protection.