Underground Station lighting

[farecard]

I was at Ballston and noticed new equipment atop the HVAC pylons.
It's clearly power supplies for the lighting bouncing off the ceiling.
https://www.meanwell-web.com/en-gb/ac-d ... -185h--48b
It looks like they are replacing older lighting with LED.
I note I did not identify the light as LED; they must have worked to get good multi-spectrum output

[davinp]

Metro needs to repair the one at Capitol South. The lights are not working on 2 of the brown pylons making it dark in certain areas of the platform

[wrivlin]

Saw them at Court House a few days ago. Doesn't look like they've been turned on yet.

[farecard]

Did these replace units recessed inside the pylons?

[Sand Box John]

"farecard"
Did these replace units recessed inside the pylons?

Looks like yes. The vapor lamps they replaced were fitted in a cone that was part of the diffuser at the top of the pylon. The reason why these LED luminaries stand proud of the top of the pylon is because of the heat sink on their back side. Those power supplies are mounted on the side of heat sink. I have a couple of salvaged LED street lights, the heat sinks on them are ginormous.

[STrRedWolf]

https://wtop.com/tracking-metro-24-7/20 ... -stations/

In short: 10 times brighter in stations, 24,000 MW saved now due to switching to LED, done a year earlier thanks to the pandemic.

Reminds me of George Carlin on one of his routines. "Weather tonight: DARK! Continued darkness until morning."

[Sand Box John]

STrRedWolf
https://wtop.com/tracking-metro-24-7/20 ... -stations/

In short: 10 times brighter in stations, 24,000 MW saved now due to switching to LED, done a year earlier thanks to the pandemic.

24,000 MW is roughly equal to $2.5 million. The cost to upgrade the legacy lighting packages in the 48 underground stations was $45.6 million.

In my view the lighting improvements are far more important then the energy savings.

[farecard]

Also consider reduced maintenance, and its saving.

[Sand Box John]

farecard
Also consider reduced maintenance, and its saving.

The last underground stations opened 21 years ago. As far as I know most of original fixtures dating back to the mid 1970s remained in service. Service life of the fluorescent tubes is around 10 years. I think WMATA push that limit beyond 10 years before doing complete swap outs of the tubes. Vapor lamps have a service life that is a little less then half of fluorescents. Service life of LEDs using present technology is 5 3/4 years.

[R36 Combine Coach]

The last underground stations opened 21 years ago.

In fact the last segments of the 103 mile system designated by Congress. The Glenmont extension, Green Line mid-city route and southern Green Line in Maryland completed the "final system" as established.

[farecard]

Service life of the fluorescent tubes is around 10 years.

The sources I find mention 10,000-20,000 hours for tubes. I don't know what lighting is turned off outside of operating options, but if I assume they run 20 hr/day; that's 1.5~3 years.

Service life of LEDs using present technology is 5 3/4 years.

I was working this week on spec'ing a quantity of T8 tubes. They come with a 5 year warranty; that's about 44,000 hours or 2190 days of 20 hours; or 6 years service. And that's a warranty time, not mean lifetime. I expect they will last 1.5X warranty at least.

[Sand Box John]

R36 Combine Coach
In fact the last segments of the 103 mile system designated by Congress. The Glenmont extension, Green Line mid-city route and southern Green Line in Maryland completed the "final system" as established.

The main point is most of the fixtures at the time of the upgrade date back to the building of the stations.

farecard
The sources I find mention 10,000-20,000 hours for tubes. I don't know what lighting is turned off outside of operating options, but if I assume they run 20 hr/day; that's 1.5~3 years.

I was working this week on spec'ing a quantity of T8 tubes. They come with a 5 year warranty; that's about 44,000 hours or 2190 days of 20 hours; or 6 years service. And that's a warranty time, not mean lifetime. I expect they will last 1.5X warranty at least.

WMATA leaves the lights on in the tunnels and underground stations 24/7. In my experience fluorescent light not cycled off and on have a longer service life. Your 10,000 to 20,000 figures are on the conservative side compared to reality.

[R36 Combine Coach]

R36 Combine Coach
In fact the last segments of the 103 mile system designated by Congress. The Glenmont extension, Green Line mid-city route and southern Green Line in Maryland completed the "final system" as
established.
The main point is most of the fixtures at the time of the upgrade date back to the building of the stations.

Are these the last stations built on original 1970s design?

[Sand Box John]

R36 Combine Coach
Are these the last stations built on original 1970s design?

6 coffered arch vault in place of the original 22 coffered arch vault. Fluorescent in the light troughs, vapor lamps on the pylons, incandescent in the can fixtures.