# Cable Brake



## Evan08 (Mar 22, 2011)

I need to drop a HV armored cable down 500' on a high rise job. Long story short: pulling cable up just isn't a possibility for many different reasons. So, does anybody know of a cable brake system?


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## HARRY304E (Sep 15, 2010)

Evan08 said:


> I need to drop a HV armored cable down 500' on a high rise job. Long story short: pulling cable up just isn't a possibility for many different reasons. So, does anybody know of a cable brake system?


What do you mean by a cable brake system? :blink:


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## Evan08 (Mar 22, 2011)

Like a "cable choke" to slow the cable down and control it as it goes down. It's heavy as hell


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## HARRY304E (Sep 15, 2010)

Evan08 said:


> Like a "cable choke" to slow the cable down and control it as it goes down. It's heavy as hell


I see ,That is something to give some thought about but in this case maybe the guys that do heavy commercial industrial stuff will check in .

I do not know.


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## Shockdoc (Mar 4, 2010)

wedge chokes ?


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## wildleg (Apr 12, 2009)

never done a vertical pull like that. if something like an ultrafeeder is too scary (doesn't have enough a$$), cable trailers have brakes and they make a thing called a retriever for tensioning lineman style pulls. maybe you could crane a trailer up with your spools. heres a link:
http://www.brooksbrotherstrailers.c...emblies/12-inch-tensioning-brake-assembly.php


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## dronai (Apr 11, 2011)

I heard that you want to pull up or else !


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## pjg (Nov 11, 2008)

Assuming the cable is going to be on a reel of some sort, I would try to find a way to control the reel. Without knowing the room you have, a single reel trailer with brakes or the like may do the job(craned to the work area or maybe a freight elevator).

how much does the cable weigh?


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## stuiec (Sep 25, 2010)

pjg said:


> Assuming the cable is going to be on a reel of some sort, I would try to find a way to control the reel. Without knowing the room you have, a single reel trailer with brakes or the like may do the job(craned to the work area or maybe a freight elevator).
> 
> how much does the cable weigh?


Want to be _damn_ sure the cable is secured to the reel if you do it this way. Also, would the decreasing weight of the reel on the trailer be balasting / tip over issue?


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## pjg (Nov 11, 2008)

stuiec said:


> Want to be _damn_ sure the cable is secured to the reel if you do it this way. Also, would the decreasing weight of the reel on the trailer be balasting / tip over issue?


There are certainly many factors to be considered before attempting this task. This won't be easy in any aspect. Contacting a rigging company might 
be a place for some help as well.

I agree the trailer would definitly need to be secured and a safety on the cable. I would be contacting the cable manufacturer and asking them for advice and stresses on the cable if its hanging 500 ft. without support.


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## 360max (Jun 10, 2011)

pjg said:


> There are certainly many factors to be considered before attempting this task. This won't be easy in any aspect. Contacting a rigging company might
> be a place for some help as well.
> 
> I agree the trailer would definitly need to be secured and a safety on the cable. I would be contacting the cable manufacturer and asking them for advice and stresses on the cable if its* hanging 500 ft. without support.*


*
*
It has to be supported according to code. See 300.10 ('08 code)


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## pjg (Nov 11, 2008)

360max said:


> [/b]
> It has to be supported according to code. See 300.10 ('08 code)


 
I agree, but it will need to hang during the install for some amount of time. This may be another issue to be addressed.


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## nitro71 (Sep 17, 2009)

Can this cable handle being suspended 500' without any reliefs? I think you need to feed this down 100' then out a junction box. Wedge, anchor or otherwise strain relief it then feed it another 100' or some derivative of that. If the manufacture says it's good for 500' then you have an engineering problem. You might check with your local universities mech engineering school. See if they would be intrested in helping you design something easy and cost efficient if there isn't an off the shelf solution.


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## pwregan (Apr 13, 2011)

why wouldn't this have been a piped and pull in conductors type install instead of hanging 500 feet of armored cable?
sounds like the wrong aplication for an armored cable, the only thing i can think of is kellems every 30 feet or so to hold weight and not stress the outer armor.
i would strongly suggest you pull this cable up from the bottom- too dangerous to go top down-imhop


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## qckrun (May 18, 2009)

I would get in contact with a company that does windmill applications. I've heard of them pulling conductors up to the top from the bottom. 

Just a note things like this in an industrial setting would be in buss duct or multiple splice boxes with wedges at each box. 

I've pulled 350s bottom to top with boxes and wedges in an 8 story building before. My friend has done a 30 story building but it was all buss duct. 

Is it to late to change the design?


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## John (Jan 22, 2007)

yes..but you have to be more specific as to what you are really trying to do.


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## John (Jan 22, 2007)

I will try a guess at this....

Use a continuous loop of rope with a pulling sheave at the bottom and a capstan puller at the top. Attach the cable to the rope and pull the cable down using the winch. Attach the cable to the rope every 5 ft as you pull the cable down.
Winch and rope need to be rated for the whole weight of the cable. 



Crazy? Yes.:whistling2::blink:


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## sarness (Sep 14, 2010)

Me next!

Why not winch the whole spool down the shaft and clamp as you go? (dont go bottom up, wouldn't want to work under that!)

Another is to start at the bottom clamping off and use a sheave to form a loop pulling it up. At most you would have 250' unsupported.


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## nitro71 (Sep 17, 2009)

250' unsupported is a lot of cable. I'm not sure if the OP is talking about armored MC style or a copper outer type sheath but think about the strain on the cable at 250' hanging. I doubt the cable is designed for that.


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## John (Jan 22, 2007)

nitro71 said:


> 250' unsupported is a lot of cable. I'm not sure if the OP is talking about armored MC style or a copper outer type sheath but think about the strain on the cable at 250' hanging. I doubt the cable is designed for that.


 You do know that the OP is an apprentice and we are getting information (very little) through his inexperience.


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## sarness (Sep 14, 2010)

nitro71 said:


> 250' unsupported is a lot of cable. I'm not sure if the OP is talking about armored MC style or a copper outer type sheath but think about the strain on the cable at 250' hanging. I doubt the cable is designed for that.


I agree, just throwing things against the wall and see what sticks 250' is better then 500'

Even so you could tie off at various points on the cable and support it that way.


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## gilbequick (Oct 6, 2007)

Use a tugger, but use it as brake


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## Control Freak (Mar 8, 2008)

Pull up man. Never pull down.. Ever unless it's a fiber optic riser cable. Also by armored do you mean MC or MI Cable?


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## Control Freak (Mar 8, 2008)

Also pls specify what type and also what size conductors. I do big pulls so shoot me a private message and I'll help u out 
;-) !


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## dronai (Apr 11, 2011)

Control Freak said:


> Also pls specify what type and also what size conductors. I do big pulls so shoot me a private message and I'll help u out
> ;-) !


You've done the kind of pulls he's talking about in the high rises ?


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## John (Jan 22, 2007)

Sometimes threads turn into a version of the "telephone game". the op starts with a simple one liner with very limited information and 25 posts later it is completely off track with a life of it's own.


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## Kevin_L (Nov 18, 2011)

I am working with the OP on this project. It's a 50 story hi-rise with an indoor sub-station on the roof  Our company took over this project only a few weeks ago and have a bit of a mess to clean up. This cable is a 3c #2 15kv armoured (MC) cable 850' in length. Currently it is on the roof and there is no crane on site anymore as the structure is complete so we can't really get the reel down to pull up. 

I have done a number of hi rise's pulling teck cable up the tower and also dropped them down but not to this length or weight. Each floor is situated with a closet in the public corridor where we have cans in the slab for cable's and conduit and eventually where the meter centres are for the res. units.










the can on the right is for the hv cable. These closets essentially go all the way down the tower with a few variances on the lower floors. The can is just big enough for the cable so having anything tied to it to support it at various points along the way as it goes down isn't possible. Essentially we need a way to control the cable at the top as it goes down. We don't have a lot of room on the roof and it is covered in drain rock. 

I was thinking of setting up a tugger as was mentioned to use as a brake and attach the rope to the cable until it gets to the first can, have a number of guys throughout the closets to strap the cable, then reset the rope further back, undo the straps and continue dropping. it would be a slow process but that's all I can think of.


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## Dennis Alwon (May 9, 2009)

I was surprised to read that the nec allows long runs with armored cable. I also realize this question is CEC not NEC. I would think 500' with no support except at the top and bottom would be an issue but it appears not.

Don't they make a motorized cable feeder- basically a tugger but on the top side to control the speed of descent?


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## Southeast Power (Jan 18, 2009)

Just my 2 cents worth.
I dont think you will really be in much trouble until you are about 1/4 of the way down. The advantage you have is that you are going through cores and not in an open chase.
You should think of stationing your people about every 5 floors with two sets of straps and unistrut.
It will be slow going but this might work:
Attach a support to the cable near the ceiling at each of the locations on the designated 5 floors. 
Lower the cable until the support hits the floor.
Attach a new support to the cable and in a coordinated effort remove the first support that is now near the floor.
Now attach the support to the cable near the ceiling.
Lower the cable until the support hits the floor.

You should be able to safely lower the cable 10' or so at a time.


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## BBQ (Nov 16, 2010)

Dennis Alwon said:


> Don't they make a motorized cable feeder- basically a tugger but on the top side to control the speed of descent?


Yes Greenlee makes a feeder but I would not count on it to hold back that much weight. It only grabs the cable by pinching it between two tires.


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## sparky105 (Sep 29, 2009)

Dennis Alwon said:


> I was surprised to read that the nec allows long runs with armored cable. I also realize this question is CEC not NEC. I would think 500' with no support except at the top and bottom would be an issue but it appears not.
> 
> Don't they make a motorized cable feeder- basically a tugger but on the top side to control the speed of descent?


yes it is an issue and they will need to support it all the way down. that cable will pull itself apart if they pull on the armor with rope or calums grip 
the only way is loop it on the floors below as they go down letting out the loops slowly more men the better and then clip it to the wall on strut. up is better with rope and pulling fingeres but they are stuck on the roof.


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## Big John (May 23, 2010)

sparky105 said:


> ...That cable will pull itself apart if they pull on the armor with rope or calums grip....


 I agree, and here's the problem: Wouldn't that also happen in the final install? When trying to support that much conductor weight vertically, aren't the cable clamps basically holding the armor and not the cable?

As far as pulling it, how much room do you have on each floor? It would be a massive pain in the ass, but what about breaking the total run into 7-8 smaller manageable pulls, and just taking the slack out across the floors?

-John


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## sparky105 (Sep 29, 2009)

no the cable is ridged it is not being moved so the supports stop it from sliding it does how ever need many supports to take the mass and stop it from sliding


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## BBQ (Nov 16, 2010)

sparky105 said:


> no the cable is ridged it is not being moved so the supports stop it from sliding it does how ever need many supports to take the mass and stop it from sliding


Huh?


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## sparky105 (Sep 29, 2009)

BBQ said:


> Huh?


what?


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## Kevin_L (Nov 18, 2011)

The cable will ultimately have 3 clamps per floor once it's all said and done. It will be fine because each clamp will only be holding essentially 3 ft of cable. 

As for pulling slack out every so many floors it will be tough because they are all framed in for the res. units. Ideally that's what I'd like to do but it should have been taken care of months ago when the floors where completely open.


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## Southeast Power (Jan 18, 2009)

So we are talking about 1500 lbs or so.

The big mistake here was having it on the roof.

Is it this PVC jacketed cable?

http://mega-ex.com/product_general/... CABLE/1 KV UP TO 35 KV/MV-90 MC 15 KV 3C.pdf


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## pjg (Nov 11, 2008)

If the reel is on the roof and accessible from the (sky) top , check into a helicopter to take it off the roof and pull the cable up. Copters are expensive but so is damaging the cable


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## John (Jan 22, 2007)

pjg said:


> If the reel is on the roof and accessible from the (sky) top , check into a helicopter to take it off the roof and pull the cable up. Copters are expensive but so is damaging the cable


Good Idea. :thumbsup:
The cost of moving the cable from the roof to the ground floor may be equal to or less that the cost and hasel of trying to to pull the cable from the roof to the ground floor.

Is it common to put the sub-station on the roof of a 50 story building? I have never done work on a building more than 10 stories and the one's that have had a substation in it was on the basement or first floor.


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## Big John (May 23, 2010)

John said:


> ...Is it common to put the sub-station on the roof of a 50 story building...?


 Pretty much. It becomes very expensive very quickly trying to get 480 volts up that many stories. Taller highrises will often have a substation every 30-40 floors.

-John


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## BBQ (Nov 16, 2010)

Big John said:


> Pretty much. It becomes very expensive very quickly trying to get 480 volts up that many stories. Taller highrises will often have a substation every 30-40 floors.
> 
> -John


I worked in a large 3 story building in Somerville that has a 13.8 KV service to the center of the roof that supplied three 480 volt services up there.


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## Big John (May 23, 2010)

BBQ said:


> I worked in a large 3 story building in Somerville that has a 13.8 KV service to the center of the roof that supplied three 480 volt services up there.


 Must've been one hell of a load...?

-John


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## Kevin_L (Nov 18, 2011)

pjg said:


> If the reel is on the roof and accessible from the (sky) top , check into a helicopter to take it off the roof and pull the cable up. Copters are expensive but so is damaging the cable


One of our owners has a heli, I should ask him  not sure if there would be any kind of permissions from the city authorities to pull that off middle of downtown Vancouver.


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## BBQ (Nov 16, 2010)

Big John said:


> Must've been one hell of a load...?
> 
> -John


I was working for the first floor tenant installing a 3000 amp 480 volt service, they had refrigeration and conveyer system loads. 

In the mean time the 2ed and 3rd floor tenant had a xrap load of 103 guys working, no one would talk and the tenant had no signs.

All I know for sure is they had deep pockets, three - 3000 or 4000 amp 480 volt buss ducts dropping in from the roof and the roof had a lot of security cameras and Leibert condensers. It seems it was a data center but not one with any name. 

I love Google ....

http://maps.google.com/maps?hl=en&ll=42.376948,-71.079809&spn=0.000904,0.001729&t=h&z=20&vpsrc=6

Notice all the Gensets as well.


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## Kevin_L (Nov 18, 2011)

John said:


> Is it common to put the sub-station on the roof of a 50 story building? I have never done work on a building more than 10 stories and the one's that have had a substation in it was on the basement or first floor.


All of the towers I've done (30 and 40+ stories) have all had them in the parkade. I've had a few elec. rooms on say the 6th flr or so with a 2250 kva 600 - 120/208 transformer to feed the residential part of the building but nothing HV. This place has a HV switching room in the basement with a couple other substations for different parts of the project.


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## wildleg (Apr 12, 2009)

well, whatever you do, make sure someone takes a video so we can watch the fun.


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## Southeast Power (Jan 18, 2009)

BBQ said:


> I was working for the first floor tenant installing a 3000 amp 480 volt service, they had refrigeration and conveyer system loads.
> 
> In the mean time the 2ed and 3rd floor tenant had a xrap load of 103 guys working, no one would talk and the tenant had no signs.
> 
> ...


I dont think Data Centers like to advertise their location with building signage.


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