back box mounting

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ElectronDance

ElectronDance

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i am looking for a solution to a device mounting issue, kind of outside the box at this point and hoping someone has seen an answer I cannot find. I am working with Wheelock EMNA dual strobe/speaker units for MNS. Spec calls for a 4sq deep with an extension ring, device mounting holes match up to a standard 4sq configuration. Here's the issue I keep running into. The speaker unit has a 10oz magnet, rather large, and the footprint of the speaker unti is about 3 1/2". the terminals sit on the side of the speaker. So, you have to fit the loop wires (4 12g solid, 4 14g solid in our installations) into the terminals and turn them back in about 1/4" of space. This is leading to a lot of grounds on the system, as our installers are having trouble making things fit into a 4sq. without forcing the device and knicking the wire jackets (yes I know, more cautious installers would be the obvious answer, but I've got what I've got, and I'm a big fan of job simplification and idiot proofing anyways.)

So, my thought was to use 4 11/16" boxes and extension rings for the extra room. But, to accomplish this I would need some sort of flat plate adaptor to mount to a 4-11 and provide 4sq. configured threaded mounting holes. Been searching hard and haven't found such an animal, does one exist? I can make this work on ceiling mounted devices, as I can drill holes in the speaker mounting plate for the 4/11 box mounting and the plate is pre tapped for the device screws. Wall devices I need a different solution.

My other thought was 12 and 14 awg crimp style insulated 90 degree pin connectors. I know they exist, but have not been able to find a source for them.

Thanks for any and all help.
 
I know this isn't the answer you are looking for, but teaching your guys how to use heat shrink and a heat gun is a cheap alternative (maybe)
 
I would try lining the back of the box, or the back of the device once it's wired, with a layer of the thick pipe wrap tape that the refrigeration guys use.
 
So, you have to fit the loop wires (4 12g solid, 4 14g solid in our installations) into the terminals and turn them back in about 1/4" of space.

Do you mean that you are trying to get all that on the speaker terminals? Try pigtailing some #18 TFFN and wire nut the 12s and 14s. Push the splices to the sides of the box so they clear the magnet. Make sure you are using deep 1900 boxes, you could also use an extension but I suppose the boxes are already installed.

-Hal
 
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Chuck, I bet you could use a 2-gang device plaster ring that mounts to the 4-11/16" box by just drilling and tapping two 8/32 holes in the ring.
 
LarryFine said:
Chuck, I bet you could use a 2-gang device plaster ring that mounts to the 4-11/16" box by just drilling and tapping two 8/32 holes in the ring.
Click to expand...

If going this route, might try using a round plaster ring so that the lips of the extension don't interfere iwth the holes you drill. If you can get those wires to work atleast...
 
Good question. I run into this all of the time. Stranded wire makes a difference. I say just use more caution. I will have to get a speaker and see what else fits. Are you using the 512HD Brackets?
 
ElectronDance said:
So, you have to fit the loop wires (4 12g solid, 4 14g solid in our installations) into the terminals and turn them back in about 1/4" of space. This is leading to a lot of grounds on the system,
Click to expand...

A lot of times you can just enter the wires into the terminal strip from the opposite direction then what is 'normal'.

So instead of the conductors pointing directly into the side of the box they are pointed toward the speaker.
 
brennan said:
Good question. I run into this all of the time. Stranded wire makes a difference. I say just use more caution. I will have to get a speaker and see what else fits. Are you using the 512HD Brackets?
Click to expand...


For ceiling mounts we use the SSB4 brackets, which could easily be drilled to accomodate a 4/11 and still offer 4sq mounting holes, as the use pretapped hole patterns so as to be used without a backbox.

for wall mounts we go direct to the 4sq extension with no bracketing. We initially spec'd the units with both the SBL2 and ISP2 surface backboxes, which we have used quite successfully in the past and are the cleanest solution to the problem. ( http://www.cooperwheelock.com/products/safepath4/emna.aspx ) However, our DOD owners rep does not like the increased profile of the device set with those boxes installed, so we are being asked to mount direct to the wall.
 
The 3 things I've found to work best when working with Speaker / Strobe Appliances.

1. Electric tape
2. More Electric Tape
3. More Electric Tape
 
Stallzer said:
The 3 things I've found to work best when working with Speaker / Strobe Appliances.

1. Electric tape
2. More Electric Tape
3. More Electric Tape
Click to expand...

Well, that is the short term answer we are using. And my long term ideal is to have some trained and skilled techs dedicated to our sytems group. But, we are a new division, so at the moment it is the PM, me in the field and one JW doing rough ins... rest of the work is "catch as catch can", by pulling available bodies out of the electrical division for a day here and a day here.

But, the real driver here is that I am always looking for a better mousetrap. Tape works, care and caution work. But neither is a good mental exercise, lol. Since we dove headlong into the new MNS requirements for DOD installs, both the PM and I have been tweaking and finetuning and so on, him on the design and specification end, me on the field install end. I figure another 6 months and we will be at the level of efficiency we desire. Which is kinda the point. IMO quality, on time performance and customer relations should be givens for all companies. But the real impact on profit/loss statements is, and always was, efficiency. Build value into a system by means of efficiency of design and by creating ease of install, and you help your bottom line, and by way of value engineering, your customers.

Besides, I like these little mental puzzles. Allows me to toss questions around amongst others in the field, hand brain teasers to suppliers and often play around in the fab shop. I'm a bit strange that way... but I've noticed a lot of systems guys are. :)
 
hbiss said:
So, you have to fit the loop wires (4 12g solid, 4 14g solid in our installations) into the terminals and turn them back in about 1/4" of space.

Do you mean that you are trying to get all that on the speaker terminals? Try pigtailing some #18 TFFN and wire nut the 12s and 14s. Push the splices to the sides of the box so they clear the magnet. Make sure you are using deep 1900 boxes, you could also use an extension but I suppose the boxes are already installed.

-Hal
Click to expand...

Do NOT use pigtails. These are supervised devices. Make the connections under the wire plates ONLY.
 
Yep, pigtailing would destroy the supervision, unless you did in and out pigtails. But adding 18ga pigtails to every device on the loop is not gonna do good things in terms of loss anyways.
 
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