Siemens LC 500 Manual De Usuario
7ML19985GE01
SITRANS LC 500 – INSTRUCTION MANUAL
Page 31
m
mmmm
Int
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onnect
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Example 3
If you do not want to ground the negative connection directly, or in the case of
Intrinsically Safe applications where the DCS measures the current in the negative
connection, and that wire cannot be grounded, a barrier type is required as shown below.
Intrinsically Safe applications where the DCS measures the current in the negative
connection, and that wire cannot be grounded, a barrier type is required as shown below.
Example 4
In Intrinsically Safe applications where the DCS has galvanically separated inputs, you
can use either the type of barrier shown below, or the type shown in Example 2.
can use either the type of barrier shown below, or the type shown in Example 2.
When Ex applications are using an Ex approved Intrinsically Safe (I.S.) power supply unit,
no barrier is required and grounding is optional.
no barrier is required and grounding is optional.
3
277
1
2
PA
PA
28V
28V
110 mA
Rmeas
0 V
4
DCS APPARATUS
Type:
Ser.:
Date:
Rev.:
Ser.:
Date:
Rev.:
Tampering voids warranty
Stahl barrier: 9002/13-280-
110-00 (or equal)
hazardous area
non-hazardous area
3
1
2
PA
PA
280
160 mA
160 mA
4
DCS APPARATUS
ISS Ground
Type:
Ser.:
Date:
Rev.:
Ser.:
Date:
Rev.:
Tampering voids warranty
Stahl barrier: 9002/01-280-
110-00 (or equal)
hazardous area
non-hazardous area
DCS APPARATUS
Type:
Ser.:
Date:
Rev.:
Ser.:
Date:
Rev.:
Tampering voids warranty
I.S.