Elk wiring question

[frankv]

Hi,

I'm contemplating to replace my HAI Aegis (similar to Omni II) with an Elk Gold security system (for Insteon support). All my security sensors have a 1000ohm EOL resistor, but Elk specifies a 2200ohm resistor in their manual. Is there any way I can get around replacing the resistors (some are tough to get to) and still use them with the Elk?

Thx,
Frank

 

[BraveSirRobbin]

I don't see why you can't just put a 1.2k resistor in series at the panel since the resistors are hard to get to. "Series" means you would take one wire off the panel's terminal, replace it with the resistor, then connect the wire to the other end of the resistor (solder, crimp, etc...). This isn't the ideal way, but since you stated you can't get to the resistors, it would offer an easy solution.

 

[frankv]

I don't see why you can't just put a 1.2k resistor in series at the panel since the resistors are hard to get to. "Series" means you would take one wire off the panel's terminal, replace it with the resistor, then connect the wire to the other end of the resistor (solder, crimp, etc...). This isn't the ideal way, but since you stated you can't get to the resistors, it would offer an easy solution.

I was hoping it would be that easy, but this statement in the Elk installation manual (page 9) made me wonder:

"If EOL resistors are used, they should be placed at the furthest most remote end of the detection device wiring."

 

[BraveSirRobbin]

I was hoping it would be that easy, but this statement in the Elk installation manual (page 9) made me wonder:

"If EOL resistors are used, they should be placed at the furthest most remote end of the detection device wiring."

The key word here is 'should'. An EOL setup that way would give you optimal protection against tampering (someone cutting into your walls accessing your wiring trying to defeat the security zone). They also offer notification of wiring problems as well.

These advantages in my opinion would not be worth digging into your sensors trying to replace the resistor. As long as the normally closed circuit "sees" 2.2K it will operate with basic security functionality just fine.

Of course, we have professional installers here that will chime in to confirm or offer an alternate opinion!

 

[mustangcoupe]

One key item here is you already have 1k at the far end. So any tampering with wires should still alarm.

Todd



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[Ira]

One key item here is you already have 1k at the far end. So any tampering with wires should still alarm.

Todd



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And can't the above be verified pretty easily? Just wire the sensor the way BSR suggested, then put a jumper wire across the terminal without the 1.2k resistor and then connecting it to the "downstream" side of the 1.2k resistor (i.e., on the lead connected to your original wiring, which would take the existing EOLR out of the picture. That would simulate what someone would do if they were trying to jumper your sensor to bypass it (which is one of the things the EOL resistor guards against...right)?

 

[Del91574]

I would strongly recommend taking the time and effort to fix the EOLR issue. I've seen people attempt to do the same by mixing/matching resistors on a Ademco V-20P before and the zones never acted correctly, some would fault properly, others wouldn't fault at all.

Electrically speaking, it should work by installing a second EOLR, however I couldn't recommend this if the only thing that was stopping you from replacing the EOLR was the time and effort, unless they're physically impossible to access.

The zone will not properly show a tamper condition if the existing EOLR is shorted, the panel will most likely still set up or at most, show a high resistance fault and not an appropriate trouble condition to what is actually happening on the circuit.

 

[BraveSirRobbin]

I would strongly recommend taking the time and effort to fix the EOLR issue. I've seen people attempt to do the same by mixing/matching resistors on a Ademco V-20P before and the zones never acted correctly, some would fault properly, others wouldn't fault at all.

Electrically speaking, it should work by installing a second EOLR, however I couldn't recommend this if the only thing that was stopping you from replacing the EOLR was the time and effort, unless they're physically impossible to access.

The zone will not properly show a tamper condition if the existing EOLR is shorted, the panel will most likely still set up or at most, show a high resistance fault and not an appropriate trouble condition to what is actually happening on the circuit.

Here is what you do. The resistors will cost you three bucks. Before you go ripping out sensors and doing more damage just try it. It will most likely work. If I were going to recommend different it would be to use the 2% tollerance of resistor so the overall tollarances are not additive with the existing EOLR.

And IF you are worried about someone coming to your home, cutting through your walls to try to defeat a sensor, then yea, you will need to replace the EOLR at the end of the sensor. But, if you are just like most of us who are not protecting Fort Knox type property, it will work fine. I don't even use EOL resistors myself as I would rather have the additional noise immunity non-EOL sensors provide!

 

[Sandpiper]

If you go through the trouble of digging the sensors out to get to the EOLRs, then just eliminate the EOLR and change the zone to NC. You have just experienced one of the main disadvantages of the EOLR. I believe you will not miss the advantages they offer. To learn more, see this writeup on EOLRs.

 

[Quixote_1]

You will not miss the advantages... until you or someone working for you puts a screw or nail through one of your wires or someone gains access to your panel.

 

[Del91574]

Here is what you do. The resistors will cost you three bucks. Before you go ripping out sensors and doing more damage just try it. It will most likely work. If I were going to recommend different it would be to use the 2% tollerance of resistor so the overall tollarances are not additive with the existing EOLR.

And IF you are worried about someone coming to your home, cutting through your walls to try to defeat a sensor, then yea, you will need to replace the EOLR at the end of the sensor. But, if you are just like most of us who are not protecting Fort Knox type property, it will work fine. I don't even use EOL resistors myself as I would rather have the additional noise immunity non-EOL sensors provide!

A pack of 10 contacts costs less than $20 ^_^

I personally use the EOLR more for a troubleshooting tool because it's easier to see the loop voltages and provide 3 states on a normal NC zone. You don't troubleshoot a panel or zone by measuring resistance, it's voltage. Not a concern for someone coming in and compromising a wire/contact, however I have seen plenty of instances of cables being crushed in a raceway as well as lumber shifting/settling. I've also yet to run into a loop that had a problem with noise in almost 20 years of installing, with the exception of induction of EMP in a metalworking/welding shop.

 

[BraveSirRobbin]

A pack of 10 contacts costs less than $20 ^_^

I personally use the EOLR more for a troubleshooting tool because it's easier to see the loop voltages and provide 3 states on a normal NC zone. You don't troubleshoot a panel or zone by measuring resistance, it's voltage. Not a concern for someone coming in and compromising a wire/contact, however I have seen plenty of instances of cables being crushed in a raceway as well as lumber shifting/settling. I've also yet to run into a loop that had a problem with noise in almost 20 years of installing, with the exception of induction of EMP in a metalworking/welding shop.

In my area we have known 'instances' where cell phones quit working, people's garage doors going up automatically as well as other strange events. I really can't elaborate any more on the reasons this happens (other than it isn't aliens ), but this is why I prefer noise immunity and the simplicity of a non EOL solution.

The bottom line is there are different solutions for different problems and it really all depends on what I like to call the 'shit to worth ratio". If the OP doesn't want to risk tugging on wiring that may not have service loops, elongating the mounting hole from digging out the old sensors so a new one will not fit properly, etc... then he should opt for not touching the sensor end. If the OP decides instead of taking that chance or using one sensor as a 'trial' to see how hard it would be to replace them, for the small advantages the correct EOL will bring to his system overall, then yes sensor replacement would be for him!

 

[hagak]

In my area we have known 'instances' where cell phones quit working, people's garage doors going up automatically as well as other strange events. I really can't elaborate any more on the reasons this happens (other than it isn't aliens ), but this is why I prefer noise immunity and the simplicity of a non EOL solution.

My guess is your near and air base, seeing that your location is Las Vegas there is a fairly good size Air base near you. I use to live in Va Beach near the Naval Air Station and would see similar issues. In fact my wireless key entry to my car would not work at my home most of the time, but was fine in other locations.

 

[tmbrown97]

So, how often do we hear of tampering related to residential contacts? I mean, if anyone has seen that happen, please - share your story. It seems like overkill in a residential environment.

That said, for testing - I do believe in walk tests - do them often! It can be as simple as keeping your system on Chime and making sure you get the appropriate alerts when you open the doors and windows. Because of kids, I always make sure my door/window contacts are working as intended.

 

[Sandpiper]

So, how often do we hear of tampering related to residential contacts? I mean, if anyone has seen that happen, please - share your story. It seems like overkill in a residential environment.

That said, for testing - I do believe in walk tests - do them often! It can be as simple as keeping your system on Chime and making sure you get the appropriate alerts when you open the doors and windows. Because of kids, I always make sure my door/window contacts are working as intended.

Never seen or heard of anyone "tampering" with the wiring in order to gain access later. What I have see most often is the door kicked in.

If ANYONE has heard of a situation where the wires were shorted in order to gain later access, please chime in.....