Endress+Hauser Micropilot S FMR531, Operating Instructions Manual

Page: 27 / 100

Micropilot S FMR531 with HART/4...20 mA Wiring
E Hauser 27
Overvoltage protector
• The level transmitter Micropilot S is equipped with an internal overvoltage protector (600 Vrms
surge arrester) according to DIN EN 60079-14 or IEC 60060-1 (impulse current test 8/20
μ
s, Î
= 10 kA, 10 pulses). Additionally, the instrument is protected by a galvanic insulation of 500 Vrms
between the power supply and the (HART) current ouput. Connect the metallic housing of the
Micropilot S to the tank wall or screen directly with an electrically conductive lead to ensure
reliable potential matching.
• Installation with additional overvoltage protector HAW262Z/HAW56xZ (see XA081F-A "Safety
instructions for electrical apparatus certified for use in explosion-hazardous areas").
– Connect the external overvoltage protector and the Micropilot S transmitter to the local
potential matching system.
– Potentials shall be equalised both inside and outside the explosion hazardous area.
– The cable connecting the overvoltage protector and the Micropilot S transmitter shall not
exceed 1 m in length;
– The cable shall be protected e.g. routed in an armoured hose.
Power supply
For stand alone operation recommended via two Hauser RN221N.
mm accuracy
For measurements with mm accuracy the measured variable must be transmitted using HART
protocol to ensure the necessary resolution.
4.2.1 Connection to Tank Side Monitor NRF590
See Page 25.