Door latch bolt monitor recommendation?

[lleo]

My quest to convert my doors to electrified locks has been completed and for most it has been a success.
One issue left solving is that it is no use to lock a door if it has not been properly closed and latch bolt latched.
 
I do have recessed magnetic switches in the door frame, which were of the wide-gap variety, and not sensitive enough to detect a door ajar, even after I replaced them.
So my idea is to add a lath bolt monitor, to actually detect the door latched. SDCSecurity makes these, but they are asking an arm and leg for it, which is nothing but a micro-switch mechanically activated by the latch bolt.
 
Are there others out there that you would recommend?

 

[TurboSam]

I stole an idea that I'm pretty sure I found here if you are up for a DIY project. 
 
I drilled a dowel sized hole where the bolt goes in the door jamb, embedded a Radio Shack push button switch into a 2 or 3 inch dowel with wires extended out the back, and then put the dowel in the hole so that when the deadbolt is extended it closes the switch.  Before shoving the dowel in the hole, I dropped a wire from the top of the door frame that was connected to the wired contacts of a GE NX-650 that talks to my Elk M1.  I was able to drop the wire down behind the moulding in the door jamb cavity without removing he moulding.   I would have preferred a hard wire all the way to the Elk panel but that was impractical.
 
Now, if we arm the system and the deadbolt is not closed, the nice Elk lady tells me "Basement Unlocked, Basement Unlocked."  

 

[lleo]

Thanks for the idea, I do plan to wire back the latch bolt monitor to the panel and will be running the wire behind the molding as you suggested.
Do you have a part number for the switch you used, there are thousand of switches to consider.
Are there any purpose-built devices out there? 

 

[TurboSam]

Don't know about purpose-built devices since I never checked.
 
I'm pretty sure I used these Radio Shack 2750609 normally-open, momentary push button switches, but they also have smaller momentary/normally open ones depending on your deadbolt size.

 

[RAL]

If you want to use a plunger type switch, take a look at the GRI TS-20.

 

[Del91574]

Do you have an actual strike installed or what are you trying to monitor?

 

[lleo]

I have electrified fail-secure cylindrical locks from SDC installed on front and back of the house. Power is controlled through Elk outputs.
The locks and rules to manage them work fine, but magnetic door sensors do not notice a door ajar. So this way, locking the door is useless if the door latch is not latched.

 

[Del91574]

Not to point out the obvious, but if your door contact isn't going to pick up the door being left ajar, it's installed incorrectly or possibly the wrong type for the application.
 
I've never run across a cylindrical lock that has a status monitor built in for bolt position.
 
You can also look at securitron. Of course, those things look simple but there are a lot of moving parts on an ANSI prepped strike plate, wiring and clearances.
 
You could also look at installing a tighter tolerance DSM to supersede the normal alarm contact. Usually either sinking the magnet in a little deep or offsetting slightly should tighten up the tolerance.
 
While not ideal in a residence, installing a door closer is also a good fix to ensure the door closes and latches.

 

[lleo]

Thanks DEL! Yes, my magnetic sensors were the wide gap variety, which since I have replaced with a tighter tolerance variant. Given that the holes are lined up, this still allows for a play that just permits the latchbolt not be latched, while sensing the door closed.
I do not intend to replace my locks to get one with status monitor even f existed.
 
I can easily run wires on the frame side behind the trim, so was looking for a mechanical switch to monitor the latchbolt.
A number of options have been suggested above, I have ordered a few of the GRISK TS-20
Will see how much force they need for action. 

 

[Del91574]

They're not going to work. I have a few sitting in the console of my personal vehicle at the moment.The other posters aren't following the concept of the bolt presence in the strike vs. an actuation like a deadbolt or similar being thrown against something.
 
There's really not much force with the latch entering the strike plate/cup. Even on integral electric strikes, the bolt monitoring function does really not require much force to get the flappers or other methods to actuate.
 
If you don't want to spend about $50 for the Securitron ANSI ones (cheaper than SDC) then you're probably looking at installing a second contact that has even less tolerance and use that via a rule to not allow you to arm the system if faulted, assuming the locks are secure all the time and not run on a schedule or rule.
 
The cheapest and easiest option is to install a closer or spring hinge on the door. Required on garage doors connected to living space here.

 

[lleo]

Yes, I already ordered and received the Securitron LMS-1 which is as you said cheaper than the one from SDC.
 
But this seems designed for strikes or metal doors, the bracket/cup is a bit longer(taller) and with the microswitch mounted on the outside also wider than the standard ANSI 2 3/4 strike plate can cover. Could drill new holes in the bracket but will also require a wider cutout in my door than it is my preference.
 
For sure that material I would cut away will not stop a determined intruder, but have also young children who seem to confirm with brute force and shoulder every time a door is locked...
 
Would a Securitron LMD-1 work better, or this is what you referred to as needing a considerable force to activate?
Thanks

 

[BraveSirRobbin]

A picture of this latch would be helpful for suggesting monitoring methods.

 

[lleo]

Of course...
Attached you can see the latchbolt on the lock side and the strikeplate on the other side of this double door.
Behind the strike plate notice the wire for the latch bolt monitor to be selected.
 
 

 

[lleo]

Sorry, could not attached the other file, see it here...

 

[Del91574]

BSR, it's a standard cylindrical latch on a door. The one that goes up the strike plate and into the bolt cup. He installed an electrified handset.
 
For reference, look at almost any "standard" or builder door hardware over the last 40 years. Excluding mortises and leversets.
 
You're looking at hardware that would be installed in a commercial application anyways, so generally the jamb is going to be metal and/or the door would be metal or composite fire rated materials. There are also typically allowances to prevent preload and allow the door to close easily.
 
Either way, you're going to have to hog out material to create the hollow for the cup and the related electronics. It's the nature of the beast with electrified hardware and adding extra functions. You can remove the material, you're just going to need to extend the mounting screws further into the framing. Hollow bushings help to prevent the screws from sucking everything too tight into the frame.
 
The only other way around it would be to fab up your own leaf switch and figure out where and how to mount it in the chiseled opening where the bolt resides, then hope that something doesn't gum it up, then hope you don't have to adjust or work on it.
 
More details about how your door is framed would need to be known or you're going to need to consider the closing method, weatherstripping, a closer or similar to remove any preload that prevents the door closing properly without human interaction.
 
Of course, we don't know the type of door and opening this door is sitting in.