Elk: To EOL or not to EOL?

I understand that if I use a 2200ohm resistors in sensors that it makes the Elk M1 even more secure.

However, what if I sell the house and someone wants to put in their own alarm system; will the EOL terminated sensors work with other alarm systems or would the new owners have to replace the sensors or remove the 2200 ohm resister from each sensor?

Thanks in advance!!!

Each alarm system usually uses their own size EOL (2200 Ohms for the elk). So unless they are using an ELK they would mostlikely need to change out the resistor.
And not too meny systems let you go eol less...

Actually I would not go with an EOL. The signal to noise ratio is actually higher this way and for a residential install, it's not worth the hassle.

I do know that the Caddx series of alarms (at least the NX8 series) let's you go disable the EOL scheme.

If you did sell the house and another alarm was installed that needed an EOL resistor to run, they could always put it in the wiring closet at the board. Yes, this does not give you the "advantage" of supervised line protection, but like I said earlier, it's just not needed (IMHO) for a residential install anyways.

One thing I would be interested in is does an EOL'less system violate any type of security standard (UL for instance)? This would be good to know. Maybe our members who are professional security installers can comment on this further.

ewiz said:

I understand that if I use a 2200ohm resistors in sensors that it makes the Elk M1 even more secure.

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That depends on your definition of 'secure'. All an EOL will really do for you is supervise the line so you will know if it is shorted. Most of the time that is to protect you against yourself damage a wire (shorting it) doing remodeling, etc. It is near impossible for a thief to short a wire inside from the outside.

It's probably not worth the hassle of using EOLs and I would do without them.

Do a search for EOL. You will find many discussions of the benefits or using / not using them.

My personal opinion is to use them. That's why they exist and are called what they are.

If you sell the house, why do you care? Let the next guy decide what he/she wants to do. If the wires and sensors are there you have already done 80% of the work for them anyway. Changing EOL's out is not that big of a deal.

Awesowe responses so far. Thanks.

Let me confirm one thing. Isn't the EOL optional on all alarm systems? So the lowest common denominator is to go without EOL?

I don't think EOL is optional with all systems. Also remember that fire circuits must always use an EOL resistor to detect trouble situations. 4-wire smoke circuits additionally use an EOL relay to break the connection to the EOL resistor (forcing a trouble alert on the zone) when smoke power fails.

EOL resistors are not optional on all control panels. Many installer put them at the control if the control does not have a EOL disable programming option which makes the EOL useless.

As I stated in other threads with the EOL in place the M1 control has about +- 2 volts of transient noise immunity. With a Normally Closed zone loop the control has about 9 volts of noise immunity. When the zone input uses normally closed loop wiring, the zone is directly connected to the negative side of the power supply, giving additional transient noise immunity.


With the M1 you can program each zone for EOL, normally closed, or normally open.


I use normally closed for residential, but that is my opinion.

ewiz said:

Awesowe responses so far. Thanks.

Let me confirm one thing. Isn't the EOL optional on all alarm systems? So the lowest common denominator is to go without EOL?

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No, EOL is required on most basic systems but most installers are lazy or rushed and just put the EOL at the panel to satisfy the need of the panel but completely defeats the purpose of it. In theory they are good and they do work, but there is debate on their value in a residence. Ask IVB how he would feel about pulling out those recessed sensors to install an EOL and you will quickly learn its not as easy as it sounds. If you are just building and installing, its alot easier and no biggie to put them in, but retrofitting in EOLs can be a PITA. Another option are the G Risk sensors with embedded EOLs. If you have the 2.2k EOL for Elk and sell or decide to change panels, you likely can add a second resistor at the panel to get the value where you need it. Not the best approach but another option.

Spanky said, "When the zone input uses normally closed loop wiring, the zone is directly connected to the negative side of the power supply. . . "

Is the zone tied to ground only when it is defined as closed-loop wiring? Since each zone pair shares a common terminal, do such pairs need to be defined as the same type? Is the common terminal the side that is tied to the negative side of the power supply.

I wish I had my M1 so I could just try it.

I think that he is saying that the input terminal is being pulled to ground while in the secure mode. As opposed to floating in the secured mode (Normally Open)

Using normally closed instead of normally open is kind of like a poor mans supervision if the line is cut or broken you'll still get the alarm and it won't clear.

Those G-Risk recesssed switches with terminals and EOL inside look cool. Are they expensive?? I only 3 or 4....

I'm not planning to put window sensors in. Just motions througout...

MavRic

MavRic said:

Those G-Risk recesssed switches with terminals and EOL inside look cool. Are they expensive?? I only 3 or 4....

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You mean these? I believe they only come from G Risk in 10 packs.

cool? a sensor is a sensor. they are recessed so you never really see them. whats cool about them? just curious. simple magnets really. maybe i am misssing something. enlighten me?

Ranger Digital said:

whats cool about them?

Click to expand...

....built in EOL resistors...