KROHNE H250 M9 NEPSI Ex nA - Manual (Page 12)

4
ELECTRICAL CONNECTIONS
12
H250 M9
www.krohne.com 03/2013 - 4002616501 AD H250 M9 NEPSI Ex nA R01 en
Electrical connections
4.1 General notes
Electrical connection of the signal circuits is carried out in the integrated terminal compartment
of the indicator part. Separate conduit entries are provided for the signal output and limit
switches.
Unused conduit entries should be closed using approved blind plugs and seals. Ensure that the
seals are tight.
The connecting cables should be selected according to the applicable installation standards and
the maximum operating temperature. The outer diameter of the connecting wires must be
adapted to the sealing range of the cable entries (6...10 mm / 0.24...0.39"). The connecting cables
must be fixed and laid in such a way as to be sufficiently protected against damage.
Before connecting or disconnecting the electric connecting cable of the device, ensure that all of
the cables leading to the signal converter are de-energised relative to each other and to the
reference potential of the hazardous area. This also applies to earthing conductors (FE) and
equipotential bonding conductors (PA).
All cores that are not used must be securely connected to the earth potential of the hazardous
area or carefully insulated against each other and against ground (test voltage ≥ 500 V
eff
).
Cable entries / Blanking plugs
The variable area flowmeter is optionally equipped with one conduit entry and one blind plug or
two conduit entries. These elements guarantee protection against foreign bodies and water
(protection category) IP65 or greater. The cable entries are sealed with a plug. The plugs should
be replaced with suitable connecting cables.
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