Mounting; General Instructions - Siemens SITRANS LG270 Operating Instructions Manual

Screwing in
Protection against mois-
ture
Cable glands
Suitability for the process
conditions
PBD-51041071
4

Mounting

4.1

General instructions

On instruments with threaded process fitting, the hexagon must be
tightened with a suitable wrench. For the proper wrench size see
chapter "Dimensions".
Warning:
The housing must not be used to screw the instrument in! Applying
tightening force can damage internal parts of the housing.
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
•
When mounting horizontally, turn the housing so that the cable
gland points downward
•
Loop the connection cable downward in front of the cable gland
This applies mainly to outdoor installations, in areas where high
humidity is expected (e.g. through cleaning processes) and on cooled
or heated vessels.
To maintain the housing protection, make sure that the housing lid is
closed during operation and locked, if necessary.
Make sure that the degree of contamination specified in chapter
"Technical data" meets the existing ambient conditions.
Metric threads
In the case of instrument housings with metric thread, the cable
glands are screwed in at the factory. They are sealed with plastic
plugs as transport protection.
You have to remove these plugs before electrical connection.
NPT thread
In the case of instrument housings with self-sealing NPT threads, it is
not possible to have the cable entries screwed in at the factory. The
free openings for the cable glands are therefore covered with red dust
protection caps as transport protection. The dust protection caps do
not provide sufficient protection against moisture.
Prior to setup you have to replace these protective caps with ap-
proved cable glands or close the openings with suitable blind plugs.
Make sure before mounting that all parts of the instrument exposed 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:
SITRANS LG270 - Operating Instructions
13