Mounting; General Instructions; Mounting 4.1 General Instructions - Siemens SITRANS LG250 Operating Instructions Manual

Screwing in
Protection against mois-
ture
Cable glands
Suitability for the process
conditions
PBD-51041387
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 the recommended 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 humidity is
expected (e.g. through cleaning processes) and on cooled or heated
vessels.
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 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 are particularly:
•
Process pressure
•
Process temperature
•
Chemical properties of the medium
•
Abrasion and mechanical influences
SITRANS LG250 - Operating Instructions
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