Why Positive DC Grounding Over Floating?

Mostly I think for eliminating noise and voltage spikes effecting the signals, the positive ground allows for excess voltage leak off and minimizes corrosion...

<...minimizes corrosion...>

Er, um, motor vehicles are negative ground for that reason....

Also, if the site is relatively large, then grounding will ensure that the local voltage (relative to the other cabinets and such) will be at that same potential. Also, if anything (within reason) is incorrectly connected it will be shunted to ground rather than some unfortunate operator.

In coal mines it was referred to as "transfer potential". Even a simple pipe could run a few miles sitting on insulated supports, so if it wasn't locally grounded you encountered the transferred voltage from the pipe connection point. Combination of outgassing from coal and sparks was to be avoided at all costs.

Floating systems are complex as detection and elimination of ground fault requires special equipment and operationally complex. Yet, this is preferred in DC systems over 50V to prevent loss of supply on first ground fault.

In case of 50V and lower, the possibility of earth fault is low (considering the voltage with earth itself is low and hence the required clearance is low). This is the reason why DC system is grounded.

Seems to be a very effective, good and stable 48 volts regulation is achieved, by using positive ground, as no inadvertent and accidental voltage increase can be imparted onto the telecommunications system power supply..

Any unnecessary voltage increased is automatically shorted to the ground potential..

Dear sir

thanks for your replay

but how unnecessary voltage is automatically shorted to the ground potential.

thanks

Without a ground the system could be floating up at 2kV and no one would know until they touched it.
I know this from experience when someone built a badly designed and constructed power supply test rig... and I had to use it
Del