underground computer enclosure

Status
Not open for further replies.
G

Gizmobreaker1155

Member
Location
New Jersey
Occupation
Electrician
Good morning. Here's a distraction from the ongoing vote-counting. I have a sculpture to install on a lawn in an industrial park in Indiana. It features 1282 individually controlled 24vdc LEDs, on 16 messengers, all running from a single pole down to 16 footings arranged in a 52' diameter circle. It will require a computer to analyze weather data and send out the video signal to the LEDs, plus video decoders and power supplies. The nearest building is 350 conduit feet away and there is some concern that they don't have any space for my equipment, anyway. The artist does not want an above ground enclosure.

Each of the 16 strands of LEDs has 2 data lines and 2 power lines. 4 x 16 = 64 wires, 32 data (shielded) and 32 DC power. That's a lot of conduit diameter and 350' is a lot of voltage drop.

The only solution that seems to make sense is an underground enclosure for the computers and the LED drivers. All that equipment, of course, hates moisture and wants to be cooled. An open bottom enclosure will always be wet and a closed bottom enclosure would require a sump pump and a nearby dry well. Either way, there's likely to be moisture in the enclosure all the time. Everything can be enclosed in weather-tite NEMA4 enclosures but then cooling becomes an issue.

What's the best solution? Am I ignoring something obvious? I have a different installation in Florida where I used an air-conditioned SS enclosure but I was able to mount that to a building wall, close enough to avoid too much voltage drop. That's not possible, here. The artwork does not include any above ground structures other than the pole, which is only 8" in diameter. The footings are all flush with grade.
 
In the spirit of full disclosure, I should admit that I have never installed equipment in underground vaults though I have certainly done repairs in them. No computers or electronics in them, though.
 
Gizmobreaker1155 said:
Good morning. Here's a distraction from the ongoing vote-counting. I have a sculpture to install on a lawn in an industrial park in Indiana. It features 1282 individually controlled 24vdc LEDs, on 16 messengers, all running from a single pole down to 16 footings arranged in a 52' diameter circle. It will require a computer to analyze weather data and send out the video signal to the LEDs, plus video decoders and power supplies. The nearest building is 350 conduit feet away and there is some concern that they don't have any space for my equipment, anyway. The artist does not want an above ground enclosure.

Each of the 16 strands of LEDs has 2 data lines and 2 power lines. 4 x 16 = 64 wires, 32 data (shielded) and 32 DC power. That's a lot of conduit diameter and 350' is a lot of voltage drop.

The only solution that seems to make sense is an underground enclosure for the computers and the LED drivers. All that equipment, of course, hates moisture and wants to be cooled. An open bottom enclosure will always be wet and a closed bottom enclosure would require a sump pump and a nearby dry well. Either way, there's likely to be moisture in the enclosure all the time. Everything can be enclosed in weather-tite NEMA4 enclosures but then cooling becomes an issue.

What's the best solution? Am I ignoring something obvious? I have a different installation in Florida where I used an air-conditioned SS enclosure but I was able to mount that to a building wall, close enough to avoid too much voltage drop. That's not possible, here. The artwork does not include any above ground structures other than the pole, which is only 8" in diameter. The footings are all flush with grade.
Click to expand...

I did something very similar last year, albeit above ground. We put everything in fiberglass NEMA 4X enclosures, and installed a control cabinet air conditioner on each cabinet. The equipment makes enough heat that we didn't worry too much about cold temps in the winter, just heat and humidity. All cables in/out were through cord grips.

These enclosures were mounted in the electrical vault for the project; it was a 10' x 10' x 10' poured concrete room, with the sculpture on top. It was not heated/cooled, so it was cold-ish in the winter, and swampy humid and hot in the summer.

It sounds like you need a below-grade electrical vault where you can mount your control cabinet(s). That... won't be cheap, especially with the water intrusion and sump pump gear you WILL need to install.


SceneryDriver
 
SceneryDriver, PM me, please. I'm in NJ and a stagehand. Might know some folks, in common. Where was that sculpture installed?

10' x 10' x 10' sounds lovely but I bet they'll balk at that cost! A Hubbell closed bottom Quazite enclosure is about $3500 with the lid, and then there's the ventilation and water issues. Still, there's not a lot of other options that I can see.
 
What is the connection between the computer and led drivers? Ethernet? What's the current draw of each of the LED strands 16 strands? Meanwell makes IP67 led power supplies, those could go in the pole or in a vault. There are SPI extenders that can sit between the driver and LEDS at the led end and support long distances between the driver and extender. Perhaps the computer and drivers live in the building and power supplies and extenders live in a vault near the pole.
 
Gizmobreaker1155 said:
The nearest building is 350 conduit feet away and there is some concern that they don't have any space for my equipment, anyway. The artist does not want an above ground enclosure.
Click to expand...
Is there any opportunity to have an above ground enclosure some distance away from the sculpture (e.g., behind or enclosed in bushes) but a lot closer than 350 feet?

I definitely agree with trying to put the computer equipment in the building. Besides the better environmental conditions, I think that would be much more manageable if software, memory, etc. needs to be updated or replaced.
 
The computer sends out DVI video to a proprietary decoder, via HDMI cable. Ethernet out of the decoder to 2 proprietary 8 port data/power distribution hubs. The LED strands connect directly to the decoders, using proprietary connectors.

Each LED draws 1.5 watts. The strands are not consistent lengths and range from 68 to 92 LEDs per strand, or 102 watts to 138 watts. 1282 x 1.5 = 1923 watts, total. 1923w/24vdc = 80.125amps. If we assume that each PS is limited to 100 watts, then each strand would need 2 supplies, or 32 supplies, total. That's a lot of supplies to fit into a 8" diameter pole. Plus, service access would be a bear.
The only reason that I was hoping to put the electronics near the LEDs was my fear of data loss over that long run. I can't even say, for certain, that the data over the Ethernet cables is actually Ethernet - it could be just data over readily available cabling. I didn't worry about that, before, because I was thinking that I would have the gear together. I'll have to ask about that.
 
Gizmobreaker1155 said:
The only reason that I was hoping to put the electronics near the LEDs was my fear of data loss over that long run. I can't even say, for certain, that the data over the Ethernet cables is actually Ethernet - it could be just data over readily available cabling. I didn't worry about that, before, because I was thinking that I would have the gear together. I'll have to ask about that.
Click to expand...
If it's standard Ethernet then you could have Ethernet media converters to use optical fiber over the "long run". 350 feet is nothing for fiber. Also fiber should give more immunity to surges, lightning, noise, interference, etc.
 
Big IF, right? If it is true Ethernet, though, then the computer and decoder can be on a cabinet on the outside of the building, which would help. The power supplies and the distribution boxes would have to be underground, still.
Does anyone have experience with this sort of installation? I'm specifically wondering if I better off with an open bottom vault, which has excellent drainage, though sometimes they flood, or a closed bottom vault, which would require a pump and some sort of ventilation.
 
Gizmobreaker1155 said:
I have a sculpture to install on a lawn in an industrial park in Indiana.
Click to expand...

So, after the "artist" spends zillions more than his creation just to get it working, how long do you think it's going to last? I wouldn't get too carried away with this. I would treat it as a temporary exhibition or show.

It's really not your job to design it. Tell the genius that if he doesn't want to see any of the equipment, it's 350 feet back to the building. Give me a call when you figure it out.

-Hal
 
I am guessing that each LED string uses some sort of serial messaging similar to the WS2812 chips that are popular for hobby LED arrays. OP states that there are 2 proprietary splitter boxes that each take ethernet type input and provide the LED array connection for 8 LED strings each.

Is there any chance of getting boxes that go from ethernet to a single strand? Could you place a single string driver and a single 150W power supply in the footings at the perimeter? This means more distance for your run, but then you only need to hide a pair of small boxes at each location.

-Jon
 
winnie said:
I am guessing that each LED string uses some sort of serial messaging similar to the WS2812 chips that are popular for hobby LED arrays. OP states that there are 2 proprietary splitter boxes that each take ethernet type input and provide the LED array connection for 8 LED strings each.

Is there any chance of getting boxes that go from ethernet to a single strand? Could you place a single string driver and a single 150W power supply in the footings at the perimeter? This means more distance for your run, but then you only need to hide a pair of small boxes at each location.

-Jon
Click to expand...

Take a look at the enttec pixelator + waterproof data injector. This is what they need for this project. I wonder if they have already purchased the components (hopefully its not some random junk off ebay or aliexpress)
 
Gizmobreaker1155 said:
The computer sends out DVI video to a proprietary decoder, via HDMI cable. Ethernet out of the decoder to 2 proprietary 8 port data/power distribution hubs. The LED strands connect directly to the decoders, using proprietary connectors.

Each LED draws 1.5 watts. The strands are not consistent lengths and range from 68 to 92 LEDs per strand, or 102 watts to 138 watts. 1282 x 1.5 = 1923 watts, total. 1923w/24vdc = 80.125amps. If we assume that each PS is limited to 100 watts, then each strand would need 2 supplies, or 32 supplies, total.
Click to expand...
Also consider the power dissipation of the power supplies, LED drivers, and other electronics. Determine if forced or natural ventilation for cooling may be appropriate for the environment the electronics is in.
 
Status
Not open for further replies.
Top