ELK-M1 hookup verification & EOL resistor

[BraveSirRobbin]

Yes 2.5 Kohms sounds high. Are you sure you put 2.2 Kohm resistors in all the zones, because I believe (don't have any in front of me) that those EOL resistors are 5% tolerance which would put their max reading at 2.31 Kohms. Add 3-10 ohms for wiring and you are still off of your 2.5 Kohm bad zone readings.

Also, eight volts is the max for a non violated zone. I don't use EOL's myself but I'm wondering about your 7.3 volts for a good zone as I'm surprised that is so close to the upper range (between 4-8 volts represents a 'good' zone in it's normally closed state).

Can you take some voltage readings? Put the meter in AC voltage mode and read the wall wart of the Elk's input into the M1. This should be 16.5 volts AC.

Then put it in DC and measure an aux output.

I'm wondering about the M1's reference DC voltage.

EDIT: Just read the manual and 7 volts is the nominal non-violated zone voltage for an EOL normally closed zone.

The three zones states are:

Shorted (Trouble): 0-3.9 volts
Normal with 2.2 KOhm EOL 4.0-8.8 volts
Open 8.9 - 13.8 volts

 

[kgingerich]

I went back and re read the suspect zone and it's now reading 2.9 Kohm. There in lies the issue I'm having. If I hook everything back up the M1 will say the zone is normal although the voltage will read anywhere from 7.5V to 8V when I have checked. My guess is that it's flucuating all over and at times it goes above the 8volt reading and triggers the M1.

The suspect zone is on a zone expander that's powered by a separate transformer than the main M1. The m1 zones all read 7.1V with EOL and 13.5 without. The zone expander zones mostly ready 7.3V with EOL and 13.9V without. The power supply for the zone expander has a voltage adjustment on it... should I adjust it down to read 13.5?

 

[BraveSirRobbin]

Hmmm, the power supply may be suspect and I don't see any harm in turning the voltage down. Also, people here have stated that when using an external supply the negative should be tied back to the M1, but I don't think this is the issue.

I'm wondering why your resistance would vary so much. How were the connections made (crimp, solder, etc...)? It almost sounds like a connection is loose or maybe is getting moisture in it and causing a high resistance connection.

Also, just to verify, you have the wiring to the zone completely removed from the input board (so the zone board can not influence the reading)?

Can you take the sensor out a bit and wiggle it to see if the resistance changes while doing so (possibly lightly tug on the wiring)?

 

[michelkenny]

The suspect zone is on a zone expander that's powered by a separate transformer than the main M1. The m1 zones all read 7.1V with EOL and 13.5 without. The zone expander zones mostly ready 7.3V with EOL and 13.9V without. The power supply for the zone expander has a voltage adjustment on it... should I adjust it down to read 13.5?

The M1XIN data sheet indicates an operating range of 9 to 14 VDC for the input power, however if one were to have it powered from the M1 then it would be around 12 VDC. What is your power supply currently set to?

 

[BraveSirRobbin]

That is an excellent suggestion as the zone expander may not have voltage regulation on it, thanks Kazibole!

FYI, I measured mine that is powered off of the M1 and it was 11.6 volts DC.

I'm still concerned about his zone resistance varying so wildly though on the suspect zones.

 

[Del91574]

The resistance is key here. 7.1-.3 is ideal and normal. I have multiple 212S' that I'm looking at in RP, and via their direct supervisiory zones, that's what they're reading, no EOLR installed. 14VDC is typical of a "wide open zone" (I have a few reading 14.2VDC-14.0)

The power is it's own issue upon itself, but the main thing to make sure is any aux power supply maintains above 12VDC while running on battery (we are sizing an appropriate battery and supply on the install, right?) Anything lower than 12VDC, the board will tend to reboot, causing piles of system startups in the log and loss of all the attached zones. Any system peripherals must share a common negative.

As far as the loop voltage, that's a far more accurate way to see what's going on with the system, not resistance.

First, if you have wiring or a splice heading south, intermittently, it could swing in the manner that would cause the loop to fault. Increasing resistance=higher loop voltages. Toss that in with a fast loop response, that would also reflect in a false alarm. A bad contact, especially a recessed contact installed in wood or vinyl, that was being crushed by normal expansion/contraction would also act the same way.

I'd take a nice analog meter, set on a low scale, and an assistant with a cushioned screwdriver tap on the contacts and watch to see what the needle does....if it jumps, then you found a suspect unit. You can't use a DMM for this sort of troubleshooting, assuming there's no issue with the wiring or any splice integrity (such as a cold solder joint or similar, hopefully no twist and tape junctions).

 

[mikei-ma]

Does anyone see a problem with me using 2000 Ohm ELOR instead of 2200 Ohm on the Elk M1G? I'm at a job replacing an ADT panel with 2000 Ohm resistors and have some left in my toolbox.

 

[tmbrown97]

Do the math - is it within tolerances?

 

[Del91574]

It'll work, however it's not something I'd recommend just to "get the job done" . IMHO, it's too close to a high resistance short vs EOLR value as far as the panel is concerned. Resistors are cheap to source and find locally 9/10 times.

 

[BraveSirRobbin]

Doing a quick ratio calc (7.3 volts nominal for a good zone using a 2.2Kohm) shows you should get slightly over 6.5 volts nominal using a 2Kohm resistor.

The Elk M1 uses a range of 4-8 volts to represent a non-violated zone using EOLR.

 

[jpmargis]

I calculate just over 6.9 volts using Ohm's Law. Either way it should work just fine. You have 2.5 to 3 volts of margin.