atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Security, Alarms and Paging wiring a door strike

I have a small project to hook up an existing door strike to the phone system. I can remove the strike and see a power cable in there but I believe it goes no-where. I've checked all over, no cable, no transformer. It's a typical steel door frame.

I have a locksmith associate who can wire it for me for a fee but I am just curious how it's done. Are there typically knockouts at the top of the door frame that protrudes from the sheetrock and you snake from there down?

Any ideas are appreciated.

Can't help you with the mechanical installation particulars, but the electrical you should be aware of are that, typically, the solenoid is powered by 12-24 volts, AC or DC, at 2-5 amps. The average phone system control contacts will NOT handle that kind of power directly! So you will probably need to lay your hands on a relay with contacts that are capable of switching 24VAC @ 5 Amps. But the operating coil should be no more than 12 volts DC at 1/2 Amp. Check specs on both the strike solenoid AND the KSU control contacts!!! Sandman in Chicago comes to mind as a logical source for the relay.

yes thank you. i've done many door strikes, just never the wiring in the frame. i've got all of the pieces ready to go!

When I did door strikes/security bolts/etc. we had to drill the frame out. We needed stainless steel bits and they cost a fortune.

Sam

Some door frames ("bucks") do have knockouts for the wiring. Where they would be, in your case, is only a guess.

Have you put a tone supply on the wires, and tried to find them with an exploring probe? You might at least be able to see what general direction they head off to, and then find where they are cut off, in order to make a splice somewhere easier.

Is this a residence or a commercial building? Try looking in the basement directly under the door. The wires might be cut down there. Can anyone familiar with the building tell you if there was a button on someone's desk, before the current tenants moved in? Have you searched high and low for the transformer? It might be jury-rigged at an electrical outlet, a sub-panel, or a ceiling lamp fixture behind some "stuff."

Good luck, I feel your pain.

it's a commercial building and I did not think of the basement. I will try to look there. Otherwise I've looked everywhere!

It's an old building and there is no push button to be found nor is there an old intercom box.

I don't want to butcher the door so I guess I will get my locksmith to snake it and I'll watch!

the 1 pair 18 gauge wire usually comes down the wall then across direct to the strike in a typial installation. the negative lead goes to the power source (usually +12v dc for a strike) and the positive lead goes to the contact closure or trigger device where its acts as a bridge to the power source.

I've installed both 12v and 24v lockings systems to many different phone equipment without any third party device. And have yet to have had a problem.