power supply system - this point must be designated as one of the two DT's for both power supplies.
Thus there are exactly (N + 1) DT's in any system, where N is the number of power supplies (excluding the possibility of parallel supplies sharing the same distribution terminals or series power supplies with unused intermediate terminals).
This rule eliminates the possibility of circulating dc currents, while insuring the optimum connection of load and sensing leads and lays the groundwork for avoiding ground loops.
DC Common
One of the (N + 1) DT's determined in accordance with the preceding paragraph is designated as the CP for the system. There can be only one CP per
DC Ground Point
There must be only one GP per multiple power supply system. This rules out the possibility of connecting two grounded loads in the same system. For other notes on designating the GP, refer to DC Ground Point on page 72.
Connect the System CP to the System GP (unless one load is already grounded), making certain there is only one conductive path between these two points for the entire system. This rule also appears on page 72 and is repeated here as a reminder because of the far greater number of possible paths from dc to ground associated with multiple power supply systems. The notes on page 72 are fully applicable to multiple power supply systems.
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