by rail10
Where are these located and what type of fuse and breaker system is used to protect them on both ac from the transformer and dc side
Railroad Forums
Moderator: GirlOnTheTrain
rail10 wrote:Where are these located and what type of fuse and breaker system is used to protect them on both ac from the transformer and dc side
kitn1mcc wrote:i think it would take alot of covert the system to AC i dont even know if ac would work with the 3rd rail. one thing with ac is that they can then use just transformers plus they would have to add resistor banks for dynamic brakesI'm not sure what you meant by adding resistor banks - to the railcars or to the power gride. All of the NYC subway cars from the R-142's on have AC traction with regenerative/dynamic braking already.
railfan365 wrote:
The actual question is whether anyone knows if third rail power will be changed to AC once the cars with DC motors will all be retired, and if the inverters on the R-142 cars onward will be disabled.
Allan wrote:No matter what link I try, I get shunted to the service advisory page.
There is no specific list of these but there is a list of NYC Substations here:
http://www.mta.info/mta/museum/pdf/Powe ... %20Aid.pdf
....
http://www.mta.info/mta/museum/archiveguide.html
Allan wrote:I can tell you that there are a lot of arc rectifier substations all over the system - from what I understand nearly 200.They're still using arc rectifiers instead of solid-state? Wow.
MBTA3247 wrote: They're still using arc rectifiers instead of solid-state? Wow.At least they retired the rotary converters....
Disney Guy wrote:Mercury arc rectifiers are very efficient (around 95%), much more so than rotary converters (motor-generators). They have no moving parts and last a long time. I would think that they are less subject to damage from power surges caused by lightning compared with solid state rectifiers. I would say they fall into the category "if it ain't broke then don't fix it."I would doubt anyone has made them in decades. They were not cheap. They are a hazmat event waiting to happen; at manufacture, shipping, storage and operation. You have to preheat them for tens of minutes after moving them or they flash.