EOL Resistors: Three-State? Four-State?

[dutchyn]

Sheetrock is about to finish, and I want to terminate some of the contacts (like AMS-17) that will be hard to get at later. Looking at the ELK M1 installation manual, they show three-state EOL resistors

• open ==> alarm
• 2.2K ==> secure
• short ==> trouble

and four-state EOL resistors

• open ==> trouble
• 4.4K ==> alarm
• 2.2K ==> secure
• short ==> trouble

How many of you are actually installing the EOL resistors? Which type?

Chris D.

<edited to make the two lists parallel>

 

[Sandpiper]

Sheetrock is about to finish, and I want to terminate some of the contacts (like AMS-17) that will be hard to get at later. Looking at the ELK M1 installation manual, they show three-state EOL resistors

• open ==> alarm
• 2.2K ==> secure
• short ==> trouble

and four-state EOL resistors

• open ==> trouble
• 4.4K ==> alarm
• 2.2K ==> secure
• short ==> trouble

How many of you are actually installing the EOL resistors? Which type?

Chris D.

<edited to make the two lists parallel>

If you do a search in this forum you will find this has been discussed ad nauseum. If you don't want to look the previous discussions over, just take my advice........forget the EOL resistors. Just install an NC contact circuit.

 

[Neurorad]

To this noob, that seems like a somewhat unusual recomendation, Sandpiper, especially given the open walls.

 

[fcwilt]

To this noob, that seems like a somewhat unusual recomendation, Sandpiper, especially given the open walls.

They serve a purpose but given the tendency for people to ignore blaring alarms a criminal may be more likely to cut your phone line, break in, then silence the alarm rather then try to bypass a sensor which is what EOL resistors might detect. Of course they also will detect shorts and opens caused by, say, remodeling, which may make them worth installing. They are not difficult to install when the walls are open so why not.

 

[Steve]

Well, here's the thing. As Neurorad said, there is a ton of info pros and cons already posted if you search around. That being said, I don't think anyone has ever posted or commented on 4 state EOLs. I think they are probably pretty much used only in high security commercial installations. So, if I did EOLs at all in the house it would be the normal 3 state. But that gets to the point of should you use EOLs in the first place. You can search for the gory details but the only thing an EOL is going to do for you is tell you if there is a short on the wire, and in a residential install about the only way that's going to happen is if you damage the wire yourself doing work on the house. Many people forego the EOL and make a practice of doing a walk test after any work or remodeling is done that could impact a wire and if you do so the chances of the EOL ever being used is slim to none. Of course there are cons to using them also to consider. Since there is no standard value for the EOL, if you ever change from say an Elk to and HAI panel or something like that then you will have to pull the contact and change the EOL, or add other resistors at the panel and really kludge things up trying to get the right resistance. So, I think Neurorads suggestion which is pretty common is just to forget about them in a basic residence and just test the wires occasionally to make sure all is well. The other option is to use a contact like those by GRI that have embedded EOLs. That way if you change something all you need to do is change the contact and it is alot easier (especially with surface mount contacts).

 

[BraveSirRobbin]

I'm more worried about noise immunity in my house rather than something going wrong with the wiring so I don't use EOL's.

 

[Sandpiper]

To this noob, that seems like a somewhat unusual recomendation, Sandpiper, especially given the open walls.

Open walls are not required to install EOLRs. If an EOLR is stuck behind the drywall, this is asking for trouble. The EOLR goes onto the contact and is removable with the contact.

Again, take my recommendation and forget the EOLRs. If you will read the previous discussions on this, you will see why. Steves' post eludes to some of the reasons. As Steve stated, there is a ton of info on the pros and cons. The thing is that there is only one pro, which is a very marginal pro at best, but plenty of cons. I will not go into all of them here, just read the previous posts.

 

[Monk]

FWIW I use the 2200 ohm / 3 state with Elk. I do not physically attach the resistor to the switches, but leave them so they pull out with the excess wire if removing a switch.
If a wire is damaged or other problem occurs some point down the road, I want to know right then that it happened. In any case, it's easy to do and I somehow have not had problems. Have never done a 4-state.

Sheetrock is about to finish, and I want to terminate some of the contacts (like AMS-17) that will be hard to get at later. Looking at the ELK M1 installation manual, they show three-state EOL resistors

• open ==> alarm
• 2.2K ==> secure
• short ==> trouble

and four-state EOL resistors

• open ==> trouble
• 4.4K ==> alarm
• 2.2K ==> secure
• short ==> trouble

How many of you are actually installing the EOL resistors? Which type?

Chris D.

<edited to make the two lists parallel>

 

[Neurorad]

Slightly OT, but is a connector used to attach the EOLR to the contact or wire? Seems like a lot of exposed metal on those resistor leads - heat shrink tubing over a soldered joint?

 

[Monk]

Slightly OT, but is a connector used to attach the EOLR to the contact or wire? Seems like a lot of exposed metal on those resistor leads - heat shrink tubing over a soldered joint?

No - I solder the resistor. Yes I use heat shrink. You have to be careful that the soldered joint has no sharp points sticking out even a little bit. They will poke right thru the heat shrink. I use switches w/leads so the resistor sort of becomes part of the wire.

 

[Neurorad]

I solder the resistor
use heat shrink
switches w/leads

Thanks, Monk.

Didn't realize the greatest benefit of contacts with leads until right now.

 

[Monk]

I solder the resistor
use heat shrink
switches w/leads

Thanks, Monk.

Didn't realize the greatest benefit of contacts with leads until right now.

Indeed. You can "pre-wire" them so you don't have to mess with it @ the switch locations.