KROHNE AQUAFLUX EN - Manual (Page 9)

9
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.
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 AQUAFLUX F 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
AQUAFLUX 010 K, 020 K and 080 K compact systems
Grounding diagrams
Metal pipelines,
not internally coated
grounding without grounding rings
Metal pipelines,
with or without internal coating,
and plastic pipelines
grounding with grounding rings
R R
D2
RF RF
D3
F F
FE
(PE)
V1 V1 V2 V2
F F
FE
D3 D2 D1 D1
E E
R R
RF RF
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.
AQUAFLUX F 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.
Y Y
(PE)