12
4 Mounting
VEGABAR 18 • Two-wire 4 … 20 mA
55575-EN-200327
4 Mounting
4.1 General instructions
The instrument is suitable for standard and extended ambient condi-
tions acc. to DIN/EN/IEC/ANSI/ISA/UL/CSA 61010-1. It can be used
indoors as well as outdoors.
Note:
For safety reasons, the instrument must only be operated within the
permissible process conditions. You can find detailed information on
the process conditions in chapter "
Technical data
" of the operating
instructions or on the type label.
Hence make sure before mounting that all parts of the instrument ex-
posed to the process are suitable for the existing process conditions.
These are mainly:
•
Active measuring component
•
Process fitting
•
Process seal
Process conditions in particular are:
•
Process pressure
•
Process temperature
•
Chemical properties of the medium
•
Abrasion and mechanical influences
The permissible process pressure range is specified by "MWP" (Maxi-
mum Working Pressure) on the type label, see chapter "
Structure
".
The MWP takes the element of the measuring cell and processing
fitting combination with the weakest pressure into consideration and
may applied permanently. The specification refers to a reference
temperature of +20 °C (+68 °F). It also applies when a measuring cell
with a higher measuring range than the permissible pressure range of
the process fitting is installed order-related.
In order to prevent damage to the device, the test pressure may only
exceed the specified MWP briefly by 1.5 times at reference tempera-
ture. The pressure stage of the process fitting as well as the overload
resistance of the measuring cell are taken into consideration here
(see chapter "
Technical Data
").
In addition, a temperature derating of the process fitting, e. g. with
flanges, can limit the permissible process pressure range according
to the respective standard.
Protect your instrument against moisture ingress through the following
measures:
•
Use a suitable connection cable (see chapter "
Connecting to
power supply
")
•
Tighten the cable gland or plug connector
•
Lead the connection cable downward in front of the cable entry or
plug connector
Ambient conditions
Process conditions
Permissible process
pressure (MWP)
Protection against mois-
ture
