Wiring Analysis Paralysis

signal15 said:
I don't know if I agree that it's wasteful.  I paid $72 per 1000ft for 23AWG CAT6.  It's up to $105 now.  But, at $72, it was way cheaper than I could get actual alarm wiring for.  
About $20/M for 22/2 CM/CL2. $40/M for 22/4 CM/CL2.

Daisy chaining additional circuits isn't the way I'd choose to go using a category cable. You're asking for trouble, not to mention that most likely the splices are going to be buried or best case, left in a unfinished space, assuming attic or basement, and hopefully never finished or modified from "as built".
Pairing up individual conductors of a lighter AWG to attempt to make up ampacity is a bad idea, no matter how it's intended. Pull the right cable once. Definately too light for audio, though some have been known to cheat a single pair for a panel like the M1, but in practicality, it's asking for trouble over time.


Senior Member
DELInstallations said:
About $20/M for 22/2 CM/CL2. $40/M for 22/4 CM/CL2.

Daisy chaining additional circuits isn't the way I'd choose to go using a category cable. You're asking for trouble, not to mention that most likely the splices are going to be buried or best case, left in a unfinished space, assuming attic or basement, and hopefully never finished or modified from "as built".
Pairing up individual conductors of a lighter AWG to attempt to make up ampacity is a bad idea, no matter how it's intended. Pull the right cable once. Definately too light for audio, though some have been known to cheat a single pair for a panel like the M1, but in practicality, it's asking for trouble over time.
Not sure what splices you would be referring to.  There would be no splices except for at the contactor, just like any other wire you use.  Perhaps you are thinking that the cat6 would be completely cut in half at each location and all the other wires spliced back together.  But that would be completely unnecessary, time consuming, and it would increase your chance of problems.  It is a simple matter to remove a few inches of the outer jacket, clip either one or both of the 2 leads you are needing for that zone, and wire in your contact.  No splices at all aside from the insertion of the contactor.
For example, if it is the first contact of a series of 2 or more and you are using the blues, pull out the 2 blues, clip just one of them, insert your contactor, and move on.  The last in the series gets both the solid and striped cut and connected as the terminating device, along with the eol resistor if used.
If you have multiple zones all going to the same general part of the house, this would greatly reduce wire pulling effort.
Breaking a loop would definately not be the preferred method, especially considering how much larger a category cable pair is compared to a single 2 or 4 conductor station wire.
You're never going to be able to pull the cable out of a contact hole unless you install 3/4" contacts by daisy chaining and breaking off pairs. If you're daisy chaining by snipping a single conductor, you're never going to be able to pull the cabling out, so it's going a lesson in futility and I wouldn't want to service the system. It's really not saving the effort unless it's an extremely difficult wire pull where pulling multiple cables is very difficult or impossible.
In my area of the country, many AHJ's will frown upon any jacket removal of field cabling within a wall, etc. I've experienced them failing a rough-in where the contractor used contacts with wire leads and while the splices were neatly crimped and taped, facilitating servicing by being pulled through the standard 3/8" hole, they did not want any splices, no matter what the purpose, to exist in a wall, otherwise an electrical box was needed.
The key point I have is the walls are open, you have the chance to pull the proper cabling in an appropriate and efficent manner. In the overall scheme of things, how much is a 2/22 or 4/22 going to cost to pull compared to all category cabling and it's inherent difficulties to be worked with in a practical manner when putting a system together? It's a drop in the bucket for what the cabling costs, even considering  pulling spares and home runs to every point in the house. The cheapest part of any system (barring the extreme copper pricing swings of recent times) is always going to be the cabling.
I'd rather work on a 50-100 point system, home ran, with alarm cabling before one wired using category cabling.....now what is done with all the extra pairs? How much additional hardware is needed? How about fittings to bush the openings into enclosures and cable management. It's not about ease and what's available from X distributor, it's about using the right cable for the application, and in the case of security, contrary to popular belief, there are many applications where UTP is NOT desired or recommended because of the problems it introduces.


Senior Member
So here is a lesson in futility.
Attached is a video of me removing the jacket from a 2 inch section of cat5, separating the blues, cutting the solid blue and srtipping 1/4 inch.  At this point you would splice your contact in the same as you would no matter how you did your wire.  You would continue the cat5 on to the next window (or whatever) where you would do the same thing again, until you got to the last contact on that zone.  At this point you use both the solid blue and striped blue.  Put your EOL resistor between the contact and the striped wire.  At the panel, solid blue goes to positive and striped goes to neutral.  The CAT5 could continue on to another bank of windows, a door, whatever, and here you would do the same thing but use a different pair.  
The same thing works with standard alarm wire as well.  The razor knife does not cut the insulation on the internal conductors when you use it like this.  I have done it hundreds of times.  
I didn't say it can't be done, I know how to do it also, but you're asking for troubles over time, especially when it comes time to service the installation. It's a really bad idea to suggest wiring using this method. 
So how do you pull the inline splice back out of a typical, nominal 3/8" hole that is used in an alarm application? Do you leave a 4-5' coil in the location and hope you can pull the pair you connected to out of the small hole? What about a smaller 1/4" hole, as used with some surface contacts? Do you pigtail off the multiconductor with a single pair and bury the splice in the wall, hoping for the best?
Doing a wiring method like this if the cabling is going to be accessable and exposed (unfinished basement, drop ceiling) is one thing, but suggesting this method for a hard surface finished area is definately not recommended, nor what a real pro within the industry would do. The lesson is buy and run the right cable the first time. The walls and ceilings are open once, daisy chaining a pile of devices on a single cable during a prewire to save, at most, $1 a run is ridiculous.
Reminds me of the "prewires" done by some builders and contractors up here...drop tails of 2-3' of wire down to the basement, then run and splice everything after on a trim, if they get it. Sure, save a pile of wire on the rough, but now you've got hundreds of splices on all the cabling, none of which is long enough to reach the panel or a common junction point.


Senior Member
I don't think you are getting what I am saying at all.  There are no extra splices at all.  There are the bare minimum of splices, 2 per contact for the entire run all the way back to the panel.
The contacts have 6 inches (or so) of pigtail wire coming off of them.  First install all the contacts and let the tails dangle in the stud space.  Then you run cat5 from the panel past every single one of those contacts.  Leave a little slack in the wire so you can work with it as it passes each contact.
Then you do what I just did in the video and splice in the contact.
If you want to use the screw down terminal contacts, then you would need to leave more slack.  Probably this method is not ideally suited for using screw downs since you would need to have 3 or 4 inches of the other wires looped in the wall behind the contact.  Perhaps another trade person might come in and damage the wire that is a bit more vulnerable.  But it is always a wise idea to check these things just before the sheetrock goes up regardless of how you did it.
I did use regular alarm wire in my house and actually went up to 18g.  But this is how I wired them in, just when I split the jacket off, there were only 2 conductors instead of 8.
Lou, you're missing my point.
Even assuming a pigtail or screw terminal, your splices are buried in the wall. Are you able to pull all the splices and both conductors out of a 3/8" hole easily or at all? Is the entire splice and split off point able to be pulled out for testing and metering purposes? If the answer is no, it's a bad practice. This has nothing to do with other trades and what may or may not happen, it's basic servicability 101. You need to be able to access all splices for field cabling and not bury them to make them inaccessable.
I've had to (unfortunately) do this more than a couple of times over the last 20 years....it's bad enough trying to pull 2 conductors and a splice on a pigtail out of a 3/8" hole, let alone 4 conductors and a splice.  If you can't pull the splice out and jump a section through for troubleshooting or service, how can you eliminate what the actual issue is.
I'll point out some alarm system history and field experience.
Back in the day, many pros would use 2 conductor zippered cable, ie: lamp cord, in 22 AWG. As panels moved into solid state and loop voltages declined, in conjunction with EOLR's for supervision, a strange thing started happening...these systems that worked for 10-30 years started having issues. Installs that had security screens started having corrosion issues and high resistance faults. The culprit in part was the loop voltages and current started to decline when the panels changed. When you run higher loop voltages, splices and cabling runs "cleaner" and the faults either are blown out or don't happen (I've experienced this on takeover systems installing the M1, 7VDC loops vs. 3VDC on the prior panel). Less loop voltage and the cable, while not often, but with certain cable construction and types, I've seen firsthand the cable rot out or corrode from the inside out, and not at splice points, but under the intact insulation, located with a TDR. I also discovered, while not electrically significant when considering theory, where the EOLR is installed on a panel makes a specific difference, not just in the case of supervision and ground fault detection, but also to cable longevity. Had to bring a bunch of EE's from Silent Knight and Belden back in the day out to inspect a bunch of installs where cabling and sealed contacts were rotting out almost annually, but these systems were installed 20 years prior and everything ohmed out and noted on system inspections for 20 years before the swap. I say all of this because you need to be able to access the splice point from pigtail (from those style contacts) to field wiring and the splicing method (solder or crimps) to be able to troubleshoot and rule in/out causes of issues with wiring. While an extreme example, we had the zipcord leads on contacts rotting out at one point...how do you fix that if you can't pull out your slack and splice point?
As I've said before, if you're ok with the method you chose and are comfortable in not being able to access the splice point without destructive means, more power to you, but the professional way is to make sure every splice and joint from a pigtail to permanent cabling is accessable and can be serviced, If you can't access it, what's the point of leaving slack?
Trust me Lou, I know how it's done, I've been in the industry for over 20 years and have seen good, bad and ugly, including jobs where EOLR's and splices were buried in the walls...midpoint in runs.
 I just don't think it's a best practice or should be condoned in the name of saving cabling,effort, or time, especially when walls, ceilings, etc. are all open. It's the one time you have to get it right and do things that aren't possible or easy with sheetrock up.
Retrofit, sure, splice away and make sure you can access the splices, I doubt even 25% of the guys out there homerun on retrofits, but new work, prewire, it's a bad idea.


Guys, I'm sure I speak for others in this thread, I'm spliced out!  You made your point (believe me, you've made your point).  Time to move along...


Senior Member
I just want to point out that NONE of my splices are inaccessible. They are all in a box with a plate on it, or directly behind a removable sensor. I paid special attention when I installed to make sure I could access everything easily in the future.


picta said:
Somfy shades: unless the shade is very large, DC power. 16/2 plus 22/4 to each shade will cover all control options.
What do you consider large?  I've got two openings in our media room I want to put shades on remote.  A dual casement style window that is probably 4'h x 4.5'w that would be one shade, and a pretty regular sized sliding glass door (6.5-7'h x 6' w) that I would like to cover as well.  Will DC power and the wiring you mention be enough for this?  I'm trying to finish low voltage wiring and insulate so trying to narrow down the options here.


Senior Member
To be on the safe side, I would suggest wiring a 110V outlet in the same stud bay, down low, that you can tap into if needed, in the future, for each of those openings.


Thanks Neurorad, I'm still in pre-wire mode, so I can actually take a 120V line off a nearby outlet and wire them in up close towards the top of the window/door, possibly even being covered by the shade eventually for higher WAF.  But if I choose not to install them right away, I'll still have to put in a box in the wall and have a cover plate to cover it.  I assume I would hard wire this to the shades, so it might have a short run of thin armoured BX cable from this box through the solid plate into the shades.  I mean, it wouldn't require and actual outlet to be installed - that would be ugly, right?


Furthest from my mind at the time in the early 2000's was some sort of window shade control.  I have no real clue as to the reasoning but do have 1/2 switched to the wall switch outlets just about in every room in the house.  These are just double duplex metal boxes with conduit and single outlet mud plates in place for single outlets.  I have over the years added more electric circuits and utilized the conduit runs between the boxes for new circuits as they were very sparsely populated.
These days I utilize them for the Christmas decorating of candles in every window during the Holiday season.
Around same time had an alarm prewire done on new construction and personally did the rest of the LV stuff.  I did and do still have many blank covers here and there for LV wires still in place but not utilized.  I did tack on metal mudplates to studs for the LV wires even though everything was plastic such that the drywall folks would cut round the mudplates.  No conduit there; just BX for the HV stuff.  Its been so long that I do not think its noticed much these days.
You can never really have too much wire during pre finish of the construction.  While the HV is different; its easy to run with no walls in place.  Its non invasive being just time and materials.  Once the walls are up, drywall is finished, trim is in place; it's much more difficult to be non invasive for the LV/HV wiring or cabling.