Power Entry/Exit To 16 Channel LOR Box

[geogecko]

I've got 2 of my 5 CTB16KD kits assembled now, and have 12 of the 12"x12"x6" Scepter junction boxes that were on eBay a few months back, and am trying to come up with a good way to bring the cords in and out of the box.

I originally thought using a male and female 1 and 1/4" electrical conduit coupling on one side, threaded on the other, would be a good choice, but this provides no strain relief. That size, has enough play in it to get 8 output channels, and 1 input plug through, which would require 2 per 16 channel box, plus another method for getting the comm cables in/out.

I do not expect, nor want, it to be a water tight connection, just want strain relief, and decent protection from insect intrusion.

I have been looking online, and am seeing these things called EMT Compression Connectors. These look like something that may work, but until I see one in person, I won't know.

I was wondering what other people are using? It seems like a lot of people are using something like a large cable clamp (maybe similar to what the Showtime LOR boxes use), but I have to keep in mind, that these Scepter boxes are around 1/4" thick in the walls, so I need that, plus some more, to thread a nut on it to keep it in the box. I prefer plastic, but am thinking I may have to use these EMT things, which are metal.

I prefer not to provide some other kind of strain relief inside the box, but if that is the only option, I guess I'll look into it.

Also, what about the comm cables? I could strain relief those with some other method, inside the box, such as, adhesive cable tie downs, through a regular 1/2" male/female coupler as described above.

I liked the idea of the waterproof single cable inlet devices, but those things are really expensive, especially, given you need like 20 per box...

[grandlakedad]

I don't think the EMT fitting is what you are looking for either. It is made to clamp flexible conduit and doesn't have a lot of clamping movement such as a regular wire clamp does. See the photo as I believe this is what you are refering to.


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[grandlakedad]

I think this would be a better solution. It can be attached directly to your box.
By the way if anyone can tell me how to attach more than one picture I wouldn't have to double up on replys.


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[ranger_391xt]

Here is a link to a couple old e-bay auctions for some of the liquid tight cord grips.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290236242551

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290233020965

I bought some 1/2" NPT from the seller earlier this year. I'd keep checking for him to list more, as he's been selling them off and on throughout the year. Sellers e-mail is in the first listing, so you might try contacting him to see what he has available.

Chris

[geogecko]

Yeah, a standard cable clamp would probably be better, I was just looking for a more elegant solution, but may have to settle.

Those liquid tight cord grips might do the trick, if I can find them that cheap. I have sent that guy on eBay an e-mail, to see what he can come up with. If I can get them for $0.68 or less each, that is a good deal. They wanted like $6 each at the local electrical shop! I was going to get a couple for samples, until I found out how much they were. :shock:

[ranger_391xt]

Looks like he listed some of the bigger ones:

http://cgi.ebay.com/250pc-3-4-pg21-THREAD-STRAIN-RELIEF-CABLE-GLAND_W0QQitemZ290250439099QQcmdZViewItem?hash=item290250439099&_trkparms=72%3A552%7C39%3A1%7C66%3A2%7C65%3A12&_trksid=p3911.c0.m14.l1318

250 of them for $35.00 is a steal....if you can use them. A PG21 thread takes a 27Mmm hole.

Here is a spec sheet on them:

http://www.niedaxusa.com/Ipon%20Flier.pdf



Chris

[geogecko]

Thanks Chris, I have been in contact with him. His name is Mark, and he has some really good deals on these. They were such good prices, I'm ordering enough to probably cover the next 5-10 years worth of upgrades. I'm getting the size for the AC cables, and the other size for the CAT 5 cables.

I'm also going with the NPT, because he said the threads on the box side are longer than the PG versions, and these will be going through a 1/4" box enclosure, so I'll need all the threads I can get.

He has both black and gray as well.

Thanks again for this great find. I was wanting to do them this way from the beginning, but couldn't find any cheap enough to build a lot of boxes.

[ranger_391xt]

Your welcome. I think you are using the same boxes that I have as well. the 12" X 12" X 6" Scepters that came from a guy in Florida. These have worked our fairly well. One word of caution, though, if you plan to re-open to re-open the boxes. I has some of the brass inserts with the female threads back out on me, and didn't realize it. When I put the lid back on, it didn't seal, and moisture got in the box.

I use something a little different for the CAT 5.

http://www.wlanparts.com/product/RJ45-ECS/RJ45ECS_Ethernet_Connector_System_11__RJ45ECS.html

Chris

[geogecko]

Yep, same boxes. Some were a little worn looking, but for the price, you can't beat it. I'll have to pay attention to the brass inserts.

I ended up buying all he had of the size for the plugs, which was 320. I almost wish I had bought something similar to yours on the CAT5 connections. I assume there is a receptical on the outside of that contraption? I haven't seen those before. Might be worth the $5 each to be able to rearrange the CAT5 plugs, once they are installed. I didn't realize it, but I'd have to cut the connector off if I wanted to remove the wire...or at least, remove the entire strain relief.

[geogecko]

Where did you get nuts to use on the back side of the strain relief? These appear to be sold seperately from the strain relief. Also, did you use some kind of o-ring or gasket to seal between the box and the strain relief.

Did you make your boxes watertight, since you were using these? I wonder if it would be a good idea to put some of that moisture wicking stuff inside (the beaded bags), just in case there happened to be some condensation. I was planning on just putting a small weep hole on the bottom of the enclosure, to allow moisture to escape, but wasn't sure yet.

I don't think the boxes need to be watertight, I mainly just wanted something to keep the cords from being yanked out easily...

[ranger_391xt]

On the CAT5 Connectors, these give you an RJ45 connection outside the box. There is a piece similar to these other strain reliefs that you slip over the plug, onto the cable. You then plug the cable in, and screw down the strain relief. They have worked pretty well for me.

As far as the nuts go, I don't have a consistent source. I got about 100 of e-bay for a really good price. Aliied Electronics has them for around 32 cents I think. That would be for the Altech brand.

I don't use any kind of washer or O-Ring. One thing I do is I thread the holes in the box. You can pick up a set of NPT taps at Harbor Freight.

Hope that helps.

[geogecko]

Awesome. Thanks for the information. 32 cents for a nut is not an option, that's almost twice what I'm paying for the 1/2" strain reliefs! Any reason you felt you needed to go with a nut, even after threading the box? I would think a 1/4" of threads would be enough to hold it in, wouldn't it?

I'll check out eBay, but it is looking harder and harder to find 3/8" nuts, so I may just scrap the CAT5 strain reliefs, and buy some of the kind you bought. After all, I don't need many of those, just 10 right now. I think I saw some of the 1/2" nuts out there for a decent price, so I may just pick some of those up.

Thanks for your help.

[geogecko]

I bought some of the RJ45 jacks from this site, had a little better price, especially when getting more than 10.

http://www.bizsyscon.com/product.php?wastoproduct=yes&id=1448

[geogecko]

Ranger, got any pictures of a controller you built?

I got everything in finally, well, except for the 1/2" nuts. The RJ45 jacks are pretty cool.

I was thinking about having everything come out the bottom, but don't know if there is enough room on the bottom of the box for that. Should be, just 20 ports coming out... I could have the RJ45's come out the sides, down near the bottom, but the jacks stick out quite a bit, and this would make putting the controllers right next to each other a bit difficult. I really don't want to put them on top!

There was another guy that built his kind of this same way, but all his pictures are now missing.

[ranger_391xt]

Here is one in a 12" X 12" X 6" Scepter Junction box.

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[geogecko]

Awesome. Thanks ranger. Looks like you were able to arrange them into lines of 4. I was not sure there was enough room or not.

Since you tapped your holes, what size drill bit did you use on the 1/2" NPTs and what size on the RJ45s? It seems like it is not a standard drill bit size, from what I can tell. Or did you buy some special NPT drill bits too?

I almost have all the materials needed. I like the idea of how you mounted the amp meter in the controller. I have some similar to those, but will house all 8 of them in one Septer box to monitor the 15A branch circuits I'm using to power the controllers...

On another note, looks like my 14 UPS boxes from Creative Displays LED lights will be showing up today!!!

[ranger_391xt]

This is a box I build last year, and all of these are M20 X 1.5, including the RJ-45 connectors. Check the lock nut that came with the RJ-45 connectors, and you should see M20 X 1.5 on there.

To tap the holes on that box, I drilled a 3/4". The actual drill size for an M20 X 1.5 tap is 18.5mm or 0.728", so I figured 3/4" was "close enough". To tap them, I used a one inch long M20 X 1.5 bolt, which I had cut some grooves in lengthwise with my dremel tool. It was amazing how hot the bolt got after tappling just a few holes.....

The drill size for 1/2" NPT X 14 is 45/64 (.703"). I'll likely just use the 3/4 drill again and call it "close enough". That should still allow plenty of thread depth when the holes are tapped. It's not like I'm building an airplane..... :-) I was in Harbor Freight over the weekend and picked up that set of NPT taps and dies I referenced in one of my previous posts. They should last forever if their only used to tap PVC...;-)

Hope that helps.

[geogecko]

Thanks ranger. I noticed the odd drill sizes as well, and though, where am I going to find something like that. Not even in my 64th drill bit set, did I have the right size... I think the 3/4" would work. I will have to order the tap set, as I do not think we have a HF close enough, but for $13, you can't beat that. Interesting method on the RJ45. I assume the slots in the bolt are to let cut material out. Interesting idea.

Thanks again for your assistance.

[ranger_391xt]

geogecko wrote:

Interesting method on the RJ45. I assume the slots in the bolt are to let cut material out. Interesting idea.

Yeah, my attempt at a "homemade" tap. PVC is soft enough I might not have needed to cut slots in it.