GE Industrial Solutions OKCV3000CN DeviceNet - Manual (Page 58)

Single Supply Center-Connected
If previous calculations indicated that you must place your power supply somewhere other than at the end of the
network, then use the following steps to determine the validity of a power supply connected at the Physical
Center of the network.
A single center-connected supply provides double the total current capability of a single end-connected supply.
1. Add the current ratings of devices in each section to determine total current in each section. Because the
supply is center-connected, the bus has two sections, one on each side of the power tap. See Figure D.9.2.
2. Using Table D.9. 1 for a thick cable trunk line, look up the maximum current capability for each section
based on the length of each section, including the power supply drop cable. Use Table D.9.2 if thin cable
trunk line is used on a section.
If the currents in both sections are less than the table value, then your network can support a single-supply,
center-connected configuration.
If your current (determined in Step 2.) in a given section exceeds the maximum current capability according to
the appropriate table, then do one of the following, based on your circumstance:
onty one
OT
tne two secuons Move tne position ottfle suppiy along tne
overloaded section and recalculate; or
Move the power supply so that one of thenodes
from the overloaded section is nowin the other
section
both sections Use two power supplies.
NI
HL2]H
Power
v+
Tap
I—
Power
Supply
Figure D.3: Single Power Supply, Center Connected
APPENDIX D
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