4
ELECTRICAL CONNECTIONS
18
OPTISWIRL 4200
www.krohne.com
01/2017 - 4004274302 - AD OPTISWIRL4200 Ex-II2G R02 en
4.1 General notes
The separate intrinsically safe signal circuits are electrically connected in the terminal
compartment of the signal converter. The circuits are designed in protection type "intrinsically
safe" and galvanically isolated from ground (test voltage
≥
500 V
eff
).
The intrinsically safe measuring sensor circuits are connected in the connection boxes on the
wall bracket and flow sensor.
The connecting cables must be selected according to prevailing installation standards
(e.g. EN 60079-14) and the maximum operating temperature.
The connecting cable between the flow sensor and wall bracket with remote systems is part of
the supply.
•
The connecting cables must be fixed and laid so they are sufficiently protected against damage.
•
All cores that are not used must be securely connected to the ground potential of the hazardous area or
carefully insulated against each other and against ground (test voltage
≥
500 V
eff
).
•
Lay cables so as to ensure that there is sufficient distance between surfaces of the flow sensor and the
connecting cable.
•
Supplied blind plugs / cable entries guarantee protection against foreign objects and water (protection
category) IP66/67 according to EN 60529.
•
Before connecting or loosening the equipotential bonding cable, ensure there are no differences in
potential.
•
Any existing cable shields should be connected to ground according to applicable installation
regulations (EN 60079-14). A terminal in the terminal compartment permits a short way grounding of
the cable shields.
•
The outer diameter of the connecting cable must be within the sealing range of the cable entry
(6...12 mm / 0.24...0.47").
•
Unused cable entries are to be closed.
Ensure that the gaskets and incised gasket ring are tight.
4.2 Power supply
Vortex flowmeters do not require a separate power supply. The required supply for the built-in
electronics is provided via the 4...20 mA current output or the bus connection.
4.3 Inputs / Outputs
The terminal assignment is described in the standard documentation. The signal circuits of the
vortex flowmeters may only be connected to certified intrinsically safe slave units or circuits.
For more information refer to chapter "Electrical data".
The current output, the current input and the binary output are designed for connection to a
certified, intrinsically safe circuit, protection type: intrinsic safety Ex ia IIC or Ex ib IIC.
The bus connections are designed for connection to a certified, intrinsically safe circuit,
protection type: intrinsic safety Ex ia IIC or Ex ib IIC according to the FISCO model.
The current output, the current input and the binary output are reliably separated up to a peak
voltage of 60 V. All signal circuits are electrically isolated from the earth.
