Safety Conventions - Endress+Hauser FEC 22 Betriebsanleitung

Safety conventions

Safety conventions
Explosion protection
Electrical symbols
Other symbols
C
H
∆C
C
X
C
S
C
X
∆C
C
L
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Safety Conventions
In order to highlight safety-relevant or alternative operating procedures in the manual,
the following conventions have been used, each indicated by a corresponding icon in
the margin.
Symbol Meaning
Note!
A note highlights actions or procedures which, if not performed correctly, may indirectly
affect operation or may lead to an instrument response which is not planned.
Note!
Caution!
Caution highlights actions or procedures which, if not performed correctly, may lead to
personal injury or incorrect function of the instrument.
Caution!
Warning!
A warning highlights actions or procedures which, if not performed correctly, will lead to
personal injury, a safety hazard or destruction of the instrument
Warning!
Explosion hazardous area
Symbol used in drawings to indicate explosion hazardous areas.
– Devices located in and wiring entering areas with the designation "explosion hazardous
areas" must conform with the stated type of protection.
Safe area (non-explosion hazardous area)
Symbol used in drawings to indicate, if necessary, non-explosion hazardous areas.
– Devices located in safe areas still require a certificate if their outputs
run into explosion hazardous areas.
Symbol
Meaning
Direct voltage
A terminal to which or from which a
direct current or voltage may be
applied or supplied.
Alternating voltage
A terminal to which or from which an
alternating (sine-wave) current or
voltage may be applied or supplied.
Grounded terminal
A grounded terminal, which as far as
the operator is concerned, is already
grounded by means of an earth
grounding system.
Protective grounding (earth) terminal
A terminal which must be connected to
earth ground prior to making any other
connection to the equipment.
Symbol Definition
Lower calibration point (capacitance
C
L
when empty)
C
H
Upper calibration point (capacitance
C
H
when covered)
∆C
Switchpoint difference
C
S
C Switchpoint (switchpoint capacitance)
S
Measured change in capacitance,
C from lower
C X
L
value: C
X
or upper calibration
= 2 x ∆C
Elektronic insert FEC 22
Symbol
Meaning
Electromechanical device
Identifies terminals to which an external
load (e.g. relays, PLC ) is connected.
Change-over contact
Indicates terminals for a relay output.
Change-over contact (Switch)
Indicates the LED showing the
switching status of the relay in the AC
version
Make contact (No contact)
Indicates the LED showing the
switching status of the output in the DC
version
Symbol Definition
Deviation of actual capacitance
dC measured by the instrument from the
set switchpoint C
S
LED LED
DC-PNP DC version with PNP output
AC version with two change-over
AC-DPDT
contacts connected in series (DPDT)
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