I’m building a new house, and looking at implementing some electromagnetic locks for the sliding doors, where a traditional ‘smart lock’ wouldn’t suit.
I’m really after some advice on whether this is a good/bad idea? I’ve only seen a handful of posts/comments about that sort of thing, and surprised it’s not more popular for the cost/simplicity involved. I’ve seen Dr. zZz’s video, and looks easy enough to DIY (even easier when just using something like a Shelly)
Maybe there’s some significant drawbacks I’m unaware of? Only main one being it unlocks in a power outage - but I think I’m ok with taking the long odds on a house break in during a powercut.
Would a 60kg lock be strong enough? That doesn’t seem like a lot… but apparently comparable to a deadbolt? 180kg seems like the next step up, but also a lot more expensive.
Durability/wear? Do they have a limited lifespan or require any specific maintenance? They seem pretty simple devices, so expect they should be reliable.
Keen to hear of anyone else’s experience with electromagnet locks.
I should add - I’m not planning on removing/adjusting the existing handles/locks, this is more so that we don’t have to use it, and can have peace of mind (for that high WAF) that the doors are all locked at night, or when we’re out.
Based on all the ones I’ve seen in commercial settings, I don’t get the impression you need to do much more than check they work.
Given that these days the advise is for multi-point locking, I’d suggest two per door, one towards the top, the other towards the bottom - that would also avoid the problem I’ve seen in some setups with magnetic locks where you can bend the door open. Maybe not enough to enter, but enough to get an arm through or a pole to pull things towards you.
Our local trade store sells magnetic door locks with a rating of 544 Kb. An online store here sells them starting in the 180 Kg to 250 Kg range, and going up past 1,000 Kg. I’d suggest that 60 Kg is fine for a cabinet, but likely insufficient for an external door. A pair of them is likely getting you into the right range, though I’d personally go with the 180 Kg units - at £15 each here those aren’t expensive.
Or, look at it this way, moving a 60 Kg weight isn’t that hard, and that’s all the cheap lock provides…
Thanks for advice, yeah I’m thinking 60kg is probably a bit low - but maybe enough to give a ‘locked door feel’ (as most burglars won’t see how much force the lock actually holds for… instead probably just go for the easier route of ‘break the huge panes of glass in front of them’?)… but yeah for the trivial cost to go stronger, should really be a no brainer…
I’m thinking of mounting it one of two ways
A) Actually inside the frame (maybe a mission to get the electromagnet etc in there?)
B) Just mounted externally with two L brackets of aluminium or something (Much easier, but less pretty)
As per attached picture (Looking top down on the sliding door)
I’m not convinced my electrician will entertain wiring random products I present him from aliexpress… but don’t want to blow out costs to just get a simple 12v line to the doors…
Also - what are your thoughts on control options - Need to have a fixed button next to the door?
Maybe some of those wireless button/switches you can just stick on the wall would do
A simple relais, why a 20euro shelly?
Both running-able on esphome. Advantage is that within esphome you don’t need mqtt but can centrally manage (including entity creation) and auto include via homeassistant api.
Ah that looks really ideal!
Um stupid question - but what is the ‘correct’ way to connect to those pins? Is there a special connector for them or something? They just seem extra exposed… especially if you’re connecting 240V to them… that’s a lot of angry pixies wanting to come out and bite…
Whichever magnet you choose, take care of the amps it draws. You should pick a suitable power supply for this. Also I would recommend to test the amount of heat it generates while powered before installing it in your walls
If you have an electrician putting wires everywhere, why not have him put a wire from the point of the magnet to somewhere convenient for you to put control (ESPHome, Shelly, whatever…) and power supply? He can use the normal 230V wire, so he will not get uncomfortable. You could even create a simple in-wall casing in a drywall by constructing it out of drywall. That stuff is a bit like lego… The electrician could then also install a wall outlet for your power supply in that enclosure.
You then have full control of all components and can easily change those in case of failure over time.
Also I would recommend the power bricks over the metal case ones. Purely because of 230V dangers. Since you now have a separate spot to put those, size does not matter any more
So from my guts feeling, I was expecting more like 2-5 Amps to hold 180kg. A quick googling found this door holding magnets: https://www.kendrion.com/en/products/solenoids-actuators/holding-magnets/door-holding-magnets
With these parameters:
For me, these seem more feasable. Still the question is not how many absolute kg the chinese magnets hold but whether it is sufficient for the application and which current they draw then
Haha, come on! I’m sure their specs are completely reliable and quality top notch!
Which also brings back the point of the 60kg locks… if that’s in reality more like 40-50kg, that’s a whole lot worse than if the 180kg lock is slightly undespecced…
Looks like you can get a 12v ac/dc transformer in DIN format which you could install in your switchboard?
Something like this:
I know DC doesn’t like traveling long distances though… but maybe that’s a safer approach? Still doesn’t answer where I’d install the shelly etc though …
If you are willing to use a switchboard AC/DC supply, you could use a DIN rail holder for f.ex. a sonoff basic (can be flashed to tasmota or ESPHome) like this one:
You would then directly switch the supply and not the relay. This could be also very beneficial for the relay, since you are not directly switching a high inductive load.
Maybe some holder for a DIN rail exists also, but I did not find those yet.
A separate wemos D1 mini + relay might be a few € cheaper, but it does not have CE-certification.
