Electric Door Strike Wiring

I am new to the forum but have been searching around here reading for quite some time now absorbing a ton of information. Thank you to everyone for sharing their knowledge.

We are building a house and I would like to prewire for an electric door strike. I know this topic has been discussed before but I couldn't find the answer to this question. The problem we have is that the door has side lights on both sides of it. How would i go about pulling wire to the strike if there is a glass unit next to the strike plate?

I have to do a bit more research to figure out the wire type to pull as well, which shouldn't be a problem once I find the appropriate door strike.

Thanks!

I was told to run a cat 5/6 wire to each location where there would be intercoms, but you may need another, bigger wire for the strike power. I am doing several doors with intercoms (cat5 should be fine) with possible video and already pre-wired those. I have not yet pulled the wire for the strike location.

The manual for whichever door strike you want to install has the recommended wire gauge depending on distance and voltage used. I recall some requiring as large 18 gauge.

Some strikes only require a pair of wires; apply DC power and the strike opens. The more fancy models also require a small amount of "keep alive" power and have built in sensors. These generally require a thicker pair for opening power and a few thinner for everything else.

If you need to run wires now and have not decided what to buy yet, the safe thing to do is run 18x2 and CAT5. This assumes your wire runs are not too long. The required guage of the power wires will depend on the latches current during opening and the wire run length. As Kazibone noted your latch manual will give you details.

FYI, many people here have had good luck with the Securitron Unlatch (UNL-12) product.

I can't answer your question on how to run wire in a door.

You may be able to pull off the trim between the door frame and the side lite. Or, if the glass is removable you can sneak some wiring around the glass opening or user a router to cut a channel in the glass opening. A picture would be helpful if possible.

18 AWG will probably be more than sufficient. If the run is short enough and you are using 24vdc you may be able to get away with 22 AWG but I wouldn't go any smaller than that. The conductor count depends on the strike.

Search "unlatch" as mentioned above and you should find lots of reading.

Agreed - the hinge side of the door is strong enough to hold the door - usually the sidelight will be shimmed up next to it. You can either fit the wire between the two sections, or even route a channel in the trim or somewhere around - when you look at the door you should be able to come up with some ideas; if not, post a picture here and you'll get plenty of options.

I would expect that the door stop is a different piece of material than the door jamb. remove that, and cut a groove in the back of it and then drill a hole through the jamb to the strike and then either at the top or bottom for the feed. Depending on how far you have to go, i wouldn't go smaller than an 18 AWG. if you can't fit an 18/2 then use smaller but splice to a larger wire as soon as you can.

Or you can use some of this thin speaker wire http://www.mcmaster.com/#audio-wire/=icm010 it is only 3/4" wide and 0.01" thick so it can literally be stuck to the surface of the jamb, painted, and no one would be the wiser.

18/2 would be the minimum size. If installing something like a Unlatch that requires a signal wire, 18/4 would be the recommended. Most of the times, distance isn't going to be the issue in a residential application. 24V would be recommended unless that's going to be the only 24V device in a world of 12V.

You DON'T want to run less than that or pigtail something smaller. The smaller wires, while they may handle the current, they typically can't handlie the inrush current, causing all sorts of issues and strange things to happen with the solenoids.

Also, keep in mind, you're going to need some depth for the strike, not so much for some that have a pass through gate for the bolt, but if you're using any that have a keeper for a night bolt or similar, you're going to be up to 2 3/4" in depth.

Most doors with insulated sidelites, it is possible to miss the lite (unless it's full length glass) and run wiring between the steel (or fiberglass) skins of the door through to the rough framing. If you've got enough clearance for the strike, you should have enough room for the DSM and be able to work behind that hole to get wiring up to the strike itself.

Unfortunately no-one has answered you first question and its a tricky one.

You will need to dismantle the woodwork a bit and see what is there. You may need to get someone to route a groove into the inside and then put the cable in and then nail/glue it back together. It is going to be near impossible to do this after its all put together. Try and do it before and while its going together. Something I wish I had done as my door has sidelights and I cant get to it now.

Door strikes are usually two wire, but you can get some that have monitoring as well. They tell you if the door is closed or not. If you have this as well then you need an extra pair of wires.

As for size. You dont need large cable. Security cable (4 core) will probably do the trick as will cable that has been mentioned above

If you have a deadbolt as well, think about a plunger switch in the deadbolt hole so you can monitor if the bolt is engaged or not. Not a hard retorfit on a standard door, but the glass will add the same difficulty.

Mick

Mick for clarity of my post,

Security cable is typically 22 AWG, far too light to be used for a strike. Even the baby conductors in an electrified hinge are larger than that (they typically provide an "equivalent" trade and ampacity)

The positioning switches that are integral to some strikes are only supposed to be used to monitor a bolt's presence, and really should not be used as a DSM...way too many issues and reasons why to not use them for status. I'd only consider them for night latch monitoring, not DSM. Then again, you're getting into a larger footprint strike, and with sidelites, making it more difficult.

While some strikes only have 2 wires for the solenoid, the motorized units are constantly powered and require a trigger input in addition to a power feed, bringing the total up to a minimum of 3-4 conductors if you're using a motorized unit (like a Securitron Unlatch)

If a "discount" strike is being sourced, other than most name brand units, I would make sure that a supressor is being installed (MOV) because most cheapies do not include them or have them integral, and that tends to cause issues with the controller hardware or strike not functioning 100% all the time.

Even if a strike can't physically fit, a lot of times an electrified handset can be installed, with the door being cored from the handset to a hinge location, usually it's the center hinge, however anywhere that can be drilled from/to can be cored for a handset. Only word of warning is if the door is supposed to be fire rated.

At 24vdc with 1/2 amp draw on 22 AWG wire I get a 1.6 volt drop on 100' of cable. I wouldn't suggest 22 AWG if you have 18 AWG.

I have seen several instances where strikes are running with 22 AWG wire in a commercial environment. I would also like to mention that these strikes are always on doors that we end up servicing that were installed by others. When we install a strike 18AWG is the minimum we use.

If you are going to use a fail secure device and plan on having it unlocked (Powered) for hours at a time 18AWG would be the better way to go.

DELInstallations said:

While some strikes only have 2 wires for the solenoid, the motorized units are constantly powered and require a trigger input in addition to a power feed, bringing the total up to a minimum of 3-4 conductors if you're using a motorized unit (like a Securitron Unlatch)

Click to expand...

Have never seen a strike with permanent power. To me the strike is that part in the frame, not the door so power is only used to energise the solenoid that latches/unlatches. Not sure how much larger they are with the monitoring option but if memory serves me correct, the ones I looked at were the same size.

Power wise - I am seeing in the order of 250mA - Calculate your cable size based on that and the voltage drop. (it may work well below the nominal 12vDC and hence 2V in voltage drop may be acceptible).

Mick,

I'm curious, since it seems like all the items you post seem to be "grey market" or non-NA items, it seems like the strike in this case, a reader in another case, and a pushbutton in a third...with a lot of unconventional installation methods, as viewed from within the trade (I've installed/serviced in NA and the EU).

In my particular case, I'm going to point out a few things. Myself or coworkers work with strikes, locks, mags, handsets and similar on an almost daily basis, with one site totalling over 2k access controlled doors, not to mention the others we deal with (and are taking over as we speak).

1. Gatchel is correct regarding cable size. It's not something that can be guessed and values plugged into a formula and factor in an arbitrary voltage drop and loss factor...items won't work or won't work properly. Every hardware manufacturer has a chart, either on the instructions or somewhere else that is conspicous with a minimum AWG, distance and voltage that is being supplied. Those charts take into consideration a lot of factors, like I alluded to, inrush is a huge one.

In the case of something like a Von Duprin or some electrified handsets, they may only draw 500 mA, however the inrush current can be up to 20A, so the cabling size of 18 or 22, which meets the continous load, would be a nice "fuse" when the inrush current comes to play.

2. I cited a specific manufacturer and model of strike that needs constant power and a trigger cable. It draws 40 mA in "standby" and up to 300 mA while "unlocking" and from experience, they sometimes draw more if there's a load or the motorized part stalls while unlocking. There are a handful of similar models by almost all the common manufacturers that operate in some similar manner, pushing back the deadlatch/bolt arrangement.

3. If monitoring the bolt via a strike you need to plan for additional cabling, splicing as well as some strikes vary if "options" exist for the strike itself. The monitoring portion is only intended for the presence of the bolt, not if the door is closed or open, a DSM contact is always the correct way to determine this. As Gatchel alluded to, if the strike is going to be held unlocked for any length of time, plan on the strike heating up pretty well, some manufacturers provide diode and resistor packs to help with the heating and voltage loading to the solenoid.

4. Voltage drop is never really desired to be more than 10%-15% variance over the listed rating of the lock, which is what most lock manufacturers will consider normal operating conditions.

Can anyone recommend an electric strike for an exterior gate, residential use? I have been reading this topic and will be building a security gate in the coming year as we settle in. Most likely it will be used in conjunction with intercom (video or simply audio).

Maglock....

Securitron M62 or similar with integral conduit fitting so sealtite or other suitable material can be used.