Siemens SITRANS LC500 Operating Instructions Manual page 39

• If the DCS measures the current through the loop compared to a common zero Volt
point, do not ground the negative side of the current loop because measurement
inputs can be short-circuited.
• If the DCS measures the current in the positive wire or connector, the negative side
of the current loop can be grounded.
• If the DCS has galvanically separated inputs for each measurement channel the
grounding method can be chosen as required.
In hazardous applications a Stahl-type barrier is required, and it is typically mounted on a
DIN rail inside a customer-supplied enclosure located in the non-hazardous area.
Example 1
If no specific Ex conditions apply, the SITRANS LC500 can be directly connected to the
DCS. The supply voltage, however, should remain within the limits set by the
SITRANS LC 500. Connecting a SITRANS LC500 to a DCS does not influence that
equipment. One of the connection cables can be grounded if desired.
GND
COAX
7ML19985GE04 SITRANS LC500 – OPERATING INSTRUCTIONS Page 33