How does Amtrak monitor/charge electric use by NEC tenant agencies?

west point wrote: ↑Thu Jun 09, 2022 3:24 pm Do not be confused by the listed voltages as it is nominal with a +/- allowable of 10%. So it is 12,000 to high 13,200 and low 10,800. If an ACS-64 is running regenerative braking and CAT voltage goes above 13,200 the motor will switch to dynamic braking. There are many reasons that the CAT voltages might go beyond these nominal limits . Amtrak has had several times when that happened causing a shutdown and reboot of the CAT power.

Equipment of any type, not just railroad equipment, always have a +/- 10% allowance for voltages. For example, Raspberry Pi CPU boards take 5V 2A power (Pi 4/400 take 5V 3A). A lot of times, you'll find a 5V charger that pumps out literally 5V but by the time it gets to the Pi, it's 4.99V or something similar. Many chargers will compensate by pumping out 5.25V, which the Pi's tolerate.

west point wrote: ↑Thu Jun 09, 2022 3:24 pm Anyone on this thread. Just think of your home electrical system. Originally nominally 110 V leg to ground and 220 V leg to leg. Nowmost circuits are 125 and 250 V My own is a couple volts higher. PRR did the same going from 11,000 volts CAT to 11,500 after WW-2 and Amtrak taking it to 12,000 Volts CAT. Raised their high voltage service as well from 132 kV to 135 kV to 138 kV nominal (10)%.

Do not be confused by the listed voltages as it is nominal with a +/- allowable of 10%. So it is 12,000 to high 13,200 and low 10,800. If an ACS-64 is running regenerative braking and CAT voltage goes above 13,200 the motor will switch to dynamic braking. There are many reasons that the CAT voltages might go beyond these nominal limits . Amtrak has had several times when that happened causing a shutdown and reboot of the CAT power.

Have read unconfirmed posts that Amtrak is buying equipment to eventually bring the 25 hZ CAT to 12.5 kV nominal. But have no reason to either believe it or not.

Why a shutdown. In Europe overhead voltage may permanently 10% up or down the designed voltage. It even allows up to 25% non permanent voor a short time. If is going up of down further the grid breakers do their job.

SRich wrote: Why a shutdown. In Europe overhead voltage may permanently 10% up or down the designed voltage. It even allows up to 25% non permanent voor a short time. If is going up of down further the grid breakers do their job.

I believe 8600 volts is the magic number when the locomotive MCB will open. The NEC electrical system is fickle at best. It was originally designed to be self-sustaining (remember.....this was the late 20's to early 30's). The only connections to the national grid are at Jericho Park, Lamokin, and Metuchen (not sure about Safe Harbor, I think that's just the hydro generators)....and that's at 138kV. The last couple of major shutdowns were cascading failures. I don't ever recall one south of the Perryville phase gap though, other than the low voltage conditions in Washington Terminal that were corrected by extending the 138kV feeders to a new substation in Ivy City (to replace the long abandoned Capitol Sub in DC).