timm33333
Device 50 is the "instantaneous overcurrent" designation according to the ANSI/IEEE Standard C37.2, while Device 51 is the "AC time overcurrent" designation. The "G" suffix typically denotes "Ground" or "Generator" (depends on the manufacturer's nomenclature) and "N" denotes "Neutral"...
At medium voltage, the sensing/processing (relay) and current interruption (circuit breaker) components of circuit protection are separate devices, while at low voltage they're usually integral parts of the same device. So your typical "circuit breaker curve" wouldn't apply in this case.
What's...
I agree with wroggent about the switch fuse locations though I think Schneider could have done a better job with the diagram. Here's my take:
Figure 5.4 - Each Load Interrupter switch/fuse combination is physically located next to the substation transformer. Since the only overcurrent...
Living2Learn, I'm in a similar situation on a current project. In my case, we have (2) 2500kW/3125kV DGs at 4160V, paralleled on a common bus. There is about 18,500kVA of installed substation TX capacity on the bus (2.96x DG capacity). I understand the transformers will eventually be fully...
