Elk: To EOL or not to EOL?

[fleetz]

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.

Hi Spanky,

This all make sense. What is the transient noise immunity with normally open? I would have thought in lightening prone areas that the normally closed would be the least likely to cause issues. Normally open would have two high impedance transmission lines just be interested in what M1 would make of it given some lightening dancing around.

Cheers,

Fleetz

 

[znelbok]

Here in Aus, the standard that covers alarm installations indicates that an EOL resistor shall be used on all external windows and doors.

Internal does not require the use of an EOL resistor.

I have used them on all my external monitoring and PIR's, but all internal doors are just NC

Mick

 

[CORT]

While we are debating the use of EOL resistors, I think we should mention the availability of door sensors with built-in EOL resistors. These sensors make using EOL resistors a "no-brainer." Personally I am a proponent of EOL resistors, especially when with the right parts, it is incredibly easy. My glass break detectors are normally closed and do not have EOL resistors, but everything else in the house has EOL resistors.

 

[Steve]

Those sensors were mentioned twice on page 1 Yes, they are good. The only downside is if someone changes panels and does not realize there are resistors in the contacts.