KROHNE ALTOFLUX M 900 EN - Manual (Page 9)

Installation and operating instruction ALTOFLUX M900 and 3080 K 9
7 Grounding
• All flowmeters must be properly grounded to avoid personnel shock hazard.
• The ground conductor should not transmit any interference voltages, therefore do not ground any
other electrical devices together with this conductor.
ALTOFLUX M900 separate primary head with terminal box
• An FE functional ground must always be connected.
• Signal converter with field power supply > 125 mA / 60 V a PE protective conductor must be
connected to the primary head, because of the higher field current from the signal converter. See
grounding diagrams below.
ALTOFLUX 3080 K compact systems
Supply power > 50 V AC
• Grounding is via the PE protective ground conductor incorporated in the power supply cable,
see also Section “Connection to power” in the installation and operating instructions for the signal
converter.
• EXCEPTION: Do not connect up the PE protective ground conductor in the terminal box
if e.g. compact units are operated in the proximity of electric furnaces, electrolysis plants, etc.,
and large potential differences occur in the pipeline system. An FE functional ground must
simultaneously take over the function of the protective conductor (combined protective/functional
ground). Refer to appropriate national codes for specific requirements for this type of installation,
which may require the addition of a ground fault detection circuit interrupter.
Power supply 24 V AC or DC
• Protective separation (PELV) must be ensured (VDE 0100 / VDE 0106 or IEC 364 / IEC 536 or
equivalent national regulations).
• An FE functional ground conductor must be connected for measurement reasons.
Grounding diagrams
Metal pipelines, Metal pipelines,
not internally coated with or without internal coating,
and plastic pipelines
grounding without grounding rings grounding with grounding rings
D1, D2, D3 Gaskets, not included with supply, to be provided by customer.
E Grounding rings (option)
F Flowmeter flanges
FE Functional ground, wire ≥ 4 mm 2 Cu (10 AWG), not included with flowmeter, to be provided by customer
PE Protective conductor required if the ALTOFLUX M900 is operated with a signal converter that supplies a field current of
> 125 mA / > 60 V. Wire
≥ 4 mm 2 Cu (10 AWG), not included with flowmeter, to be provided by customer.
R Pipeline
RF Pipe flanges
V1, V2 Interconnecting wires, included with flowmeter
Y Terminal box or signal converter