Using FireWire to keypads w/ Elk-M1DBH

J

JonR

Member
Hi all,

My big box of stuff from AO arrived and last night I started up the M1 on my table to prep for some bench testing. I ordered the Elk-M1DBH and I also took the advice of the Home Wiring 101 guide and ran 18 ga. FireWire to all my keypads in addition to Cat-5e. I'd prefer to run the keypads off the FireWire, but since the DBH uses RJ45 jacks how can I do this? Would it be possible to use the DBH for my expansion cards and also daisy-chain the keypads directly to the RS-485 bus? (I'm guessing the answer is no.) All the keypad wiring is home-run. I'm having trouble coming up with an elegant solution...

Thanks,
JonR
 
I don't know what part of the wiring guide suggested using firewire to the keypad locations (can you specify the page?). I think the intent was to run an additional 18ga wire for futureproofing in case you want some kind of keypad/screen that required separate power. What is your hesitation using the Cat5 with the DBH? The DBH loops/daisy chains, so it uses 6 wires ( 2 extra for looping the Data A and B ) and it works well. Not sure why you would want to use Firewire for keypads?
 
Steve said:
I don't know what part of the wiring guide suggested using firewire to the keypad locations (can you specify the page?).
Click to expand...

From p. 19 of the 102 doc:
"Run 18/4 Firewire to the areas where you will install security keypads. This is a code requirement in many areas."

I was figuring it would keep the keypad "alive" longer in the case of a fire. Not that I'd be hanging around playing with the keypad if the house was burning but there might be some benefit in knowing where the smoke is coming from in a large house.

JonR
 
Someone else (maybe jlehnert?) will have to explain that one. I am probably wrong, but I have not heard of anyone using firewire for keypads.
 
My understanding, without anything to back this up, is that some areas require fire rated wire for ALL life safety stuff, including keypads, sirens, low voltage power to the panel, etc.
 
I think we have a communication breakdown here. The instructions refer to fire **RATED** wire--not "firewire" as in the protocol similar to USB for connecting AV equipment and computer peripherals.

I hope you haven't run a whole bunch of firewire around your house. How much does that stuff cost on a spool, anyway?

Skip
 
MrGibbage said:
I think we have a communication breakdown here. The instructions refer to fire **RATED** wire--not "firewire" as in the protocol similar to USB for connecting AV equipment and computer peripherals.

I hope you haven't run a whole bunch of firewire around your house. How much does that stuff cost on a spool, anyway?

Skip
Click to expand...
Actually I think we are talking about the same thing. I just think of 'firewire' as either 2 or 4 conductor 18ga red wire used for smoke detectors (not IEEE 1394). I imagine there are different 'levels' of fire rating. I guess I would just ask my local inspector or building department what was required. And, if you were going to have to go to that extreme for keypads, I would imagine you would have to be careful about many other things as well. If you had a keypad wired to a remote dbh or dbhr then I guess the bus wire back to the M1 would have to be fire rated the same. And everything around the panel that could affect its operation would have to be the same.
 
WayneW said:
My understanding, without anything to back this up, is that some areas require fire rated wire for ALL life safety stuff, including keypads, sirens, low voltage power to the panel, etc.
Click to expand...



I'm pretty sure thats only for commercial installs, however the overall logic used is spot on. I don't do any commerical fire so I'm not much help.

Firewire doesn't funtion longer in a fire then anything else to my knowledge. I'm pretty sure it just has a higher quality rating and the jacket probably provides added evidence for fire investigators (was it installed correctly).

As someone else here as already found, it can actually work against you come inspection as inspectors expect it to only be used on the smokes. I wouldn't worry about it to keypad and siren though, you should be able to easily defend that.

What I can tell you for sure is in a residence, in Oklahoma, you do not need to use fire wire to the keypad or siren. Check your local codes to be sure for your area. You might also check the NFPA as they basically set the rules in the first place, however dropping $100 on a book that makes stereo instructions seem interesting is not your ideal solution.
 
WayneW said:
My understanding, without anything to back this up, is that some areas require fire rated wire for ALL life safety stuff, including keypads, sirens, low voltage power to the panel, etc.
Click to expand...

Wayne may be correct in that some localities the AHJ may want fire rated wire for any device that performs a function of the fire system (such as keypads and sounders etc).

AHJ = GOD on judgement day for a CO. (heard that from an installer that has some wild experiences with AHJ's over the years)
 
OK, I think I need to clarify. I only ran the FLPR wire to smokes, heat detectors, CO detectors, and keypads. I don't believe AHJ requires me to use the FLPR for keypads - I just ran it on the recommendation of the wiring guide and because I've got plenty of wire. If there is no real difference in performance between FLPR and Cat-5e then I'll just use the Cat-5e and leave the FLPR unused. If the FLPR is better in any way I would like to use it and the question becomes how to wire it up to the RS-485 interface. All of the Elk parts are going to be in the central automation closet so I've got lots of flexibility.

JonR
 
Personally I don't see the advantage other than a very rare situation where the house is on fire and gets to the keypad wire before you can use the keypad. If you want to use this for the keypads (personal choice) and they are homerun, you will need to use the retrofit hub (M1DBHR) instead of the regular hub (M1DBH). The DBH will require 6 wires which you do not have with the 18/4.
 
Steve said:
Personally I don't see the advantage other than a very rare situation where the house is on fire and gets to the keypad wire before you can use the keypad.
Click to expand...
A short in the keypad wiring could propagate to the main supply, maybe that's why they want "everything" fire rated.
 
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