Maximum Process Temperature Chart; Loop Power; Typical Connection Drawing - Siemens Sitrans LR250 Quick Start Manual

Maximum Process Temperature Chart

WARNING: Internal temperature must not exceed 80 °C (176 °F).
Notes:
• The chart below is for guidance only:
• The chart does not represent every possible process connection arrangement. For
example, it will NOT apply if you are mounting SITRANS LR250 directly on a metallic
vessel surface.
• The chart does not take into consideration heating from direct sunshine exposure
.
Maximum Flange and Process Temperatures versus allowable ambient for
90
80
70
60
50
40
30
20
10
0
0 10 20
Parameter 3.14.1 is required to monitor the Internal Temperature. It gives you an excellent
indication of how reliably the product will perform thermally when installed on your process
vessel.

Loop power

Typical Connection Drawing

: Loop voltage is the voltage at the terminals of the power supply (not the voltage at the
Note
terminals of the device).
power
loop voltage
supply
VL
Page EN-20 SITRANS LR250 (HART) – QUICK START MANUAL
flange adapter versions of SITRANS LR250
30 40 50 60 70 80
Process Flange Surface Temperature (
loop resistance
RL
-
+
loop current IL
flange
process
tempera-
temperature
ture
90 100 110 120 130 140
o
C)
150 160
LR250
7ML19985QX81