Siemens SIMATIC NET PROFIBUS OBT Manual page 21

Instructions for Connectoring Plastic Fiber - Optic Cables (with photos)
You can download a detailed instruction brochure with photos illustrating how to
connector plastic fiber-optic cables from the Internet:
S German:
S English:
Select SEARCH on this page and enter the number 574203 in the Entry ID box
and start the search.
Connecting the Power Supply
Figure 5-3
S The power supply for the PROFIBUS OBT must be a stabilized safety extra-low
voltage complying with IEC 950 / VDE 0805, minimum +18 V and maximum
+32 V (typically +24 V). The power source must meet the specifications of NEC
class 2 to comply with the UL/CSA approval. The unit is intended to be installed
on the load side of the class 2 or class 3 power source as defined by the
National Electric Code (NEC), Article 725-2
The module must be wired correctly according to the National Electrical code
(NEC) complying with NEC Article 725-52, 725-54, 725-61 and 725-71.
S If the PROFIBUS OBT is not installed on a grounded rail, a grounding
conductor with a cross-section of 2.5 mm
terminal to the nearest possible ground point.
PROFIBUS Optical Bus Terminal (OBT)
C79000-G8976-C122-03
http://www.ad.siemens.de/csi/net
http://www.ad.siemens.de/csi_e/net
PE M L+
NEC CLASS2
24VDC, 200 mA
Layout of the Terminal Block - Ground Terminal PE and Power Supply
Terminals M, L+
Installation and Startup
2
should be connected from the PE
5-5