16
4 Mounting
VEGACAL 66 • Foundation Fieldbus
30038-EN-200929
Use a concentric tube in non-conductive products or linearize the
meas. signal.
If condensate forms on the vessel top, the run-off liquid can cause
bridging and hence measurement errors.
For this reason, use a screening tube . The length of the screening
tube depends on the amount of condensate and the drain-off behav
-
iour of the product.
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.
Prior to setup you have to replace these protective caps with ap-
proved cable glands or close the openings with suitable blind plugs.
4.2 Mounting instructions
During operation, the probe must not touch any installations or the
vessel wall. The measured value can also change if the distance to
the vessel wall changes considerably. If necessary, secure the end of
the probe (insulated).
Depending on the size of the process fitting there is either a thread
(M12), e.g. for a ring bolt or a hole for the steel cable in the gravity
weight. The gravity weight is isolated from the measuring cable.
Make sure that the probe cable is not completely taut. Avoid tensile
loads on the cable.
Condensation
Cable entries - NPT
thread
Cable glands
Installation position
