Why do R62/A interior lights shut off periodically?

[Deucey]

T4R

[B46 via Utica]

Two reasons:

1) It hit a debris on the tracks.

2)LED lights need to be changed.

[elantra06]

Two reasons:

1) It hit a debris on the tracks.

2)LED lights need to be changed.

 

Both your reasons are wrong.

 

1) The carbody lights can shut off when passing over a 3rd rail gap leaving only the emergency lighting on for a few seconds(EX: passing over a switch) or when stopped over a switch basically a temporary loss of 600v to that car.

 

2) R62/A carbody lights are not LED

[danielhg121]

Aren't they prone to outages and the electrical wiring is kind of bad or am I getting things mixed up, i know the train along 7th avenue always cuts out esp. in Lower Manhattan but I'm pretty sure that's the third rail gap.

 

 

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[elantra06]

Aren't they prone to outages and the electrical wiring is kind of bad or am I getting things mixed up, i know the train along 7th avenue always cuts out esp. in Lower Manhattan but I'm pretty sure that's the third rail gap.

 

 

Sent from my iPhone using NYC Transit Forums mobile app

Dips in the 3rd rail and 3rd rail gaps are the causes.

[paulrivera]

I've seen it happen on the R142's as well. Most of the time I notice it leaving 125th Street on the and in either direction.

[Wallyhorse]

Both your reasons are wrong.

 

1) The carbody lights can shut off when passing over a 3rd rail gap leaving only the emergency lighting on for a few seconds(EX: passing over a switch) or when stopped over a switch basically a temporary loss of 600v to that car.

 

2) R62/A carbody lights are not LED

This used to be the norm in ALL subway cars.  

[R10 2952]

To add onto what Elantra is saying, the lights blinking over gaps is limited to the R62s, it does not affect the R62As as such.  The reason is that R62s were still built with the older electrical setup.  A good parallel can be found on nycsubway.org involving the R33/36 WF rebuild and the Mainline rebuilds:
 
"Why do the car lights blink on the R-33/R-36 World's Fair/Flushing Line cars but not the other Redbirds?

The original carbody lighting design called for the lights to be run directly off the 600V supply (with a polarity reverser relay when florescents came along). A relay called the ELR (Emergency Lighting Relay) was also across the line. When the 600V failed (car crosses a contact rail gap), the relay goes off and the normally-closed contacts of the relay apply 37V battery voltage to a set of emergency, or "battery" lights. On the IRT redbirds, these are incandescent bulbs located along the center of the car. There are some inside the long fluorescent glass fixture, and there is one each in the center of each axiflow fan.

When the R-26/R-28/R-29 fleet was overhauled by MK, the battery lights were removed from the center of the fans and PA speakers replaced them. On these cars, a solid-state converter replaces the older motor-generator set for converting 600V to battery voltage, and the same converter unit also contains a solid state lighting inverter to take the battery voltage, chop it to AC, and step it up to drive the fluorescent bulbs. When 600 goes off on these cars, the lights stay on fully for up to about 30 seconds. In prolonged power-out, the inverter gradually shuts down banks of lights until only two lights are on in the entire car.

The Flushing cars were rebuilt in 1985 by Coney Island, before the more thorough car overhaul program was devised. They left a lot of "old technology" behind, including the Motor-Generator and the classic SMEE pneumatic units. That's why those are the only cars that still go "puff" when the doors close, and why the lights still blink out across third rail gaps."


http://www.nycsubway.org/wiki/The_IRT_SMEE_Fleet_(R-12_--_R-36)

[elantra06]

I've seen it happen on the R142's as well. Most of the time I notice it leaving 125th Street on the and in either direction.

That's because the they are crossing over switches. Hence the 3rd rail gap.

[MassTransitHonchkrow]

Last week when I was on the just a few hundred feet from Rockefeller Ctr a train at West 4th Street created a massive logjam because of mechanical issues.

 

Do electrical problems contribute or correlate with these kinds of failures?

[RailRunRob]

Last week when I was on the just a few hundred feet from Rockefeller Ctr a train at West 4th Street created a massive logjam because of mechanical issues.

 

Do electrical problems contribute or correlate with these kinds of failures?

Possible if there's a voltage drop or spike. Signals in NYC from what I understand run on AC so I having issues there could also effect service independent of the DC 3rd rail or stock. Cars themselves have like 3-4 systems running internally a lot can go wrong there as well. 

[MassTransitHonchkrow]

Possible if there's a voltage drop or spike. Signals in NYC from what I understand run on AC so I having issues there could also effect service independent of the DC 3rd rail or stock. Cars themselves have like 3-4 systems running internally a lot can go wrong there as well. 

do you think new train builds are worse than their predecessors? We aren't the only agency with a train car shortage and I hear that the concerns of cracked undercarriages are mutual.

[RailRunRob]

do you think new train builds are worse than their predecessors? We aren't the only agency with a train car shortage and I hear that the concerns of cracked undercarriages are mutual.

NTT vs OTT you mean?  Hard to say But the cost of maintaining and replacing parts id have to say from someone that's been on the design side is a lot less. AC motors are brushless and easy to maintain. HVAC setups are modular.  So looking it from that way I would lean no. Maintenance is a major part of design, effects cost over its lifespan and usefulness.  Newer lighter composites and materials may also give better builds to newer cars. But the major part of any car design/build is QA and attention to detail that makes all the difference. 

[MassTransitHonchkrow]

NTT vs OTT you mean?  Hard to say But the cost of maintaining and replacing parts id have to say from someone that's been on the design side is a lot less. AC motors are brushless and easy to maintain. HVAC setups are modular.  So looking it from that way I would lean no. Maintenance is a major part of design, effects cost over its lifespan and usefulness.  Newer lighter composites and materials may also give better builds to newer cars. But the major part of any car design/build is QA and attention to detail that makes all the difference. 

thank you for that.

Other than contract name I don't really distinguish subway cars any other way.

[hamradioguy]

I'm guessing the batteries also supply the motors during the short duration there's no power from the third rail, or is it just momentum carrying the train through?

[RailRunRob]

I'm guessing the batteries also supply the motors during the short duration there's no power from the third rail, or is it just momentum carrying the train through?

With DC cars the batteries are more for backup systems like lighting and PA. As far as momentum as long as some of the other cars of the train are touching the 3rd rail they'll carry that section of the train across the gap. 

[RailRunRob]

thank you for that.

Other than contract name I don't really distinguish subway cars any other way.

No problem. A train much like a car or plane the devil's in the detail there's are dozens of different things working together per second to make these machines move the intricacy is amazing. They may seem similar but on closer inspection, the small things based on design and environment start to show themselves.     

[hamradioguy]

With DC cars the batteries are more for backup systems like lighting and PA. As far as momentum as long as some of the other cars of the train are touching the 3rd rail they'll carry that section of the train across the gap. 

Thanks that makes sense.

[Fresh Pond]

With DC cars the batteries are more for backup systems like lighting and PA. As far as momentum as long as some of the other cars of the train are touching the 3rd rail they'll carry that section of the train across the gap.

All you need is 1 shoe to touch the 3rd rail, and the whole train is electeified

[2 Train Master]

As some stated the lights flickering or going off for a few seconds is normal most common in the pre-NTT cars, however the NTT's lights do dim or/AND you can obviously know there is a 3rd rail gap because the HVAC temporarily goes out. I almost forgot this used to happen on subway cars till it was mentioned.

[ttcsubwayfan]

All you need is 1 shoe to touch the 3rd rail, and the whole train is electeified

 

 

And in the event there is no power at all, I'm assuming the output from the battery would be nowhere close to being sufficient enough to power the motors. If the subway cars work the same way the PCCs did, you should be able to brake the train to a stop even without power. 

[MassTransitHonchkrow]

No problem. A train much like a car or plane the devil's in the detail there's are dozens of different things working together per second to make these machines move the intricacy is amazing. They may seem similar but on closer inspection, the small things based on design and environment start to show themselves.     

like the new camera arrays on some of the R-179s placed near the marquee or the new display pads where artwork used to be

[RailRunRob]

All you need is 1 shoe to touch the 3rd rail, and the whole train is electeified

Yep. I've seen trains even powered by knife switches while at Kawasaki kinda the same premise. I'm sure that's what they use in the shops as well. Didn't want to get to overly complicated.

[RailRunRob]

And in the event there is no power at all, I'm assuming the output from the battery would be nowhere close to being sufficient enough to power the motors. If the subway cars work the same way the PCCs did, you should be able to brake the train to a stop even without power.

Nope out of 600VDC the motors use 480VAC the not enough for the batteries fully. The trains inverter takes one source and splits into to 3 or 4 outputs

 

It's been while I have to look into the exact specifications but for example it might look something like this

 

600VDC in

 

480VAC out (Motor)

38VDC out ( auxiliary)

80 VDC out (HVAC)

 

 

I remember Kawasaki working on something called BPS battery power system to allow trains to have a backup in power failure.

 

I'm not an expert on braking systems but pneumatic breaking should work without power. You have dynamic/rheostatic, regenerate in conjunction with brake pads and Air. An airbrake should be able to stop the train if all else fails.

[Deucey]

All you need is 1 shoe to touch the 3rd rail, and the whole train is electeified

If that's the case, since I think the longest 3rd rail gap is 200 ft, why do the lights dim or shut off, since on a 600 ft train, there's at least 3 cars/6 shoes touching the 3rd rail?