Migrate from old westec system


Active Member
I recently bought a house with an old westec 900 security system. I want to migrate to an Elk M1 but the old sensors have 1500 ohm resistance while the Elk requires 1800 ohm (I think). Is there any way to salvage the old sensors to use them in the new system? (There are dozens and dozens in this large house)

I don't see why you just couldn't add any needed resistance at the panel end. I did a post on the minimum EOL resistance that the Elk would work with.

Can't remember what that was. Spanky might know and chime in here so wait for that post or maybe try searching for it.

Welcome to CocoonTech by the way! :rolleyes:
This may not be kosher, and I'm sure someone will chime in if it isn't, but you could install a 680 ohm series resistor at the M1G panel to get the total zone resistance up to the 2200 ohms required - (necessary for every zone).

If you have a lot of buried EOLs, this may be your only option, and IMHO it should still give you the supervision you want. And, this is only for the n/c circuits. The n/o circuits like smoke detectors may not function properly if you put a resistor at the panel - but you could experiment, or perhaps Elk will comment :rolleyes:
I think you have given me a good start. In fact the Elk resistance is 2200 ohm so I think I can just add the extra resistance at the panel as you suggest. Also I plan to replace the smoke detectors and motion sensors anyway. I just wanted to avoid having to dig out and replace the dozens of reed switches. Thanks for your suggestions.

Make sure you read THIS How-To also. Since the system and wiring/sensors are old it is especially important to check them for continuity and leakage. You would get the EOL reisitance on the continuity check. :rolleyes: