Potential Equalization - Endress+Hauser Micropilot FMR50 Sicherheitshandbuch

XA00689F-A
20
• After aligning (rotating) the housing, retighten the fixing screw (see Operating Instructions).
• Continuous service temperature of the connecting cable: –40 to  +85 °C; in accordance with the
range of service temperature taking into account additional influences of the process conditions
(T and T +20 K).
a,min a,max
Intrinsic safety
• The device is only suitable for connection to certified, intrinsically safe equipment with explosion
protection Ex ia / Ex ib.
• The intrinsically safe input power circuit of the device is isolated from ground. If the device is only
equipped with one input, the dielectric strength of the input is at least 500 V
equipped with more than one input, the dielectric strength of each individual input to ground is at
least 500 V , and the dielectric strength of the inputs vis-à-vis one another is also at least 500 V
rms
• Observe the pertinent guidelines when interconnecting intrinsically safe circuits (e.g.
IEC/EN 60079-14, Proof of Intrinsic Safety).
• The device can be connected to the Endress+Hauser FXA291 service tool: refer to the Operating
Instructions and specifications in the "Overvoltage protection" (→  21) chapter.
• When the intrinsically safe Ex ia circuits of the device are connected to certified intrinsically safe
circuits of Category Ex ib for Equipment Groups IIC or IIB, the type of protection changes to
Ex ib[ia] IIC or Ex ib[ia] IIB.
Regardless of the power supply, all the internal circuits correspond to Ex ia IIC type of protection (e.g.
service interface, external display, sensor).

Potential equalization

• Integrate the device into the local potential equalization.
• For grounding the screen, →  2.
1
å 2
A Version 1
Use small capacitors (e.g. 1 nF, 1500 V, dielectric strength, ceramic).
Total capacitance connected to the screen may not exceed 10 nF.
B Version 2
1 Terminating resistor
2 Distributor/T box
3 Screen insulated
4 Supply unit/Segment coupler
5 Potential equalization (secured in high degree)
6 Field device
2 2
6
. If the device is
rms
3
A
4
C
B
4
6
5
Micropilot
.
rms
Erdung