SRA – 100 8M
page 6 of 8
Electrical connection
The electrical connection of the device must be carried out according to the respective country specific
standards. Incorrect installation or adjustment could cause applicationally conditioned risks.
Power supply input, measuring input and relay output channels are safe galvanically isolated from each other.
This is also valid for both relay output channels among each other.
Connection of the signaling transmitter resp. measuring transducer – measuring inputs
For the two or three-wire connection cable between the filling level limit switch and the signaling transmitter
resp. measuring transducer a standard installation cable or multi-wire cable for measuring intends with a
maximum of 25
per wire can be used.
The use of a shielded signal cable is not required in principle, but is recommended, if strong electromagnetic
influences could happens, e.g. due to machines or radio equipment. In that case the shielding of the cable
should be connected to earth only at the side of signaling transmitter resp. measuring transducer.
The signal cable should be installed separated from power leading wires.
If more than two limit levels with the same reference potential should be evaluated, several filling level limit
switches could be connected in parallel. For this purpose only the reference connection of all devices must be
connected with each other (see scheme below - right).
Connection of the signaling and control equipments – relay outputs
Inductive loads at the relay contacts, e.g. auxiliary contactors or magnetic vents may only be used with a free-
wheeling diode or a RC protection circuit to avoid high voltage peaks.
For inauguration it is suggested, to deactivate all connected control devices, to avoid unwanted control
reactions.
Connection of the power supply voltage
Due to the integrated wide range power supply, for connection to supply voltages from 20...253V AC / DC, the
filling level limit switch is suitable for using in all common energy supply networks.
At variants with ATEX certificate, the supply voltage range is 20...253V AC resp. 20...125V DC.
The connection is reverse polarity protected.
A switch, that is marked as separator as well as a over current protection switch (nominal current
10 A) must
be installed near the device into the supply lead.
single channel operation two channel operation four channel operation
resp. by parallel connection of two
two-position-control
s filling level limit switch SRA – 100
