Siemens SITRANS LR200 Kurzanleitung Seite 10

• Approved dust-tight and water-tight conduit seals are required for outdoor NEMA 4X /
type 4X / NEMA 6, IP67, IP68 locations.
• The maximum input voltage to the barrier must not exceed 250 V rms.
• Recommended intrinsically safe barriers are listed on page 9.
Instructions specific to hazardous area installations
• Refer to
EU Equivalency (barrier selection)
Any zener diode safety barrier, certified by an EU approved certification body to [ EEx ia ] IIC,
its output voltage (U ) not exceeding 30 V and its output current (I
o
(R ); such that I = U
o o o
IS Safety Barrier Selection
Selecting a suitable barrier or power supply requires knowledge about Intrinsic Safety and the
application. It is the responsibility of the installer to ensure that the intrinsically safe
installation complies with both the apparatus approval requirements and the relevant national
code of practice.
How to select a passive barrier for SITRANS LR200
1. Make sure that the barrier safety description is suitable for the LR200 Intrinsically Safe
(IS) input parameters.
2. Determine the maximum end-to-end resistance of the barrier (Re-e) from the data sheet.
3. Determine other loop resistance (Rloop): for example, sense resistance, displays, and/or
PLC inputs.
4. Calculate Rworking = Re-e + Rloop.
5. Determine any non-linear voltage drops due to the barrier (Vbarrier) from the barrier data
sheet (for example, voltage drops due to diodes).
6. Calculate Vworking = Vsupply – Vbarrier.
7. Using Vworking and Rworking, confirm that operation is within the shaded area of the
Loop Voltage versus Loop Resistance
graph
Notes:
• The following list is not complete: there are many safety barriers on the market, which
will work with the LR200.
• The barriers listed below have all been tested and are functionally compatible with the
LR 200.
• The barriers listed below are all HART compatible.
PLC Input Modules
Manufacturer
Siemens
7ML19985QL83
/ R , does not exceed 120 mA.
o
Part Number
SM331 PCS7 HART Input Module
SITRANS LR200 (HART) – QUICK START MANUAL
on page 10.
) limited by load resistance
o
on page 5 of Appendix A.
Page EN-9