I have an uncle that when he built his house, he built a gun safe room with a vault door. The door actually looks like a metal 6 panel door. The keypad to open the door is about 8' away in a closet and has 3 9v batteries to power the system, and uses a standard 3 line phone cord to connect the keypad to the door. The motorized mechanism in the door went bad, and a locksmith came out to repair the door. He suggested a different manufacturer and started to replace the mechanism. But he couldnt get the keypad to power the lock. When he took the keypad to the lock with a short leash, it worked. Tech support told him the longer run was losing too much current. Would replacing the pre-made wire with some cat6 add enough copper to carry amps to the lock?

Unfortunately, I dont have any data on the lock system.

While current can be an issue, think in terms of voltage drop, instead. What does the keypad need in order to operate? That should be in the specs. If the batteries were rechargeable, they AREN'T putting out 9VDC, even when new. 1.5V cells are only good for 1.2V and in the case of a 9V battery, this means it starts at about 7.2Volts.

Find out if they actually using 9V, or if the batteries are in series. Not likely, but possible.

If the problem is really caused by wire gauge, Cat6 should help, but I wouldn't want to guarantee it. 8' really shouldn't be a problem.

No way to know this without specs. That being said, most phone cable from yesteryear was 22awg. Thicker than the 23awg of even Cat6. Some Cat6 is the same awg as Cat5e at 24awg.

Without knowing how the system works, pin outs, voltages and currents involved, kind of hard to even give a recommendation.
A combo speaker wire (cat5e with 16awg/4) might work perfect. Just know way to know at this point.

Maybe the 8' piece of wire is damaged/stretched/shorted. To rule out cable length have him test with a 10' piece of new un-pulled wire and see what happens.

Unfortunately I cant get any info on the lock. I dont even know the manufacturer.

He replaced the old wire and tried 2 different new cables.

I assume he tried new, high quality batteries!

I don't trust other professionals to actually be professionals.

Maybe the keypad is not compatible with the new lock system - even thou he got it to work at the lock. If the customer is already paying for a new locking system, how much more would it really cost to replace the keypad with an approved one for the new system.

Someone needs to step up:
Either the Locksmith needs to take care of this problem, that he has been paid to start.
Or you can take over (Time & Materials) and full details from the locksmith on make & models to research.

Depending on skill set (and work load), you may not want to get involved in this at all. Which then you shouldn't.

Tech support doesn't know what they're talking about because... see Brad's comment below.


Now, I'm taking you at your word here, and the word is "replace." If you can replace the pre-made wire with some CAT6, why not replace it with some 18-2? Or even 18-4 if more than one pair is needed? CAT6 has four pairs... why would four pairs be an advantage?


Yes, it's truly unfortunate.



But how do we know it's actually phone cable?

Unfortunately, you need to analyze what's there. The thing to do here is to measure the resistance of the old strike coil and the new strike coil, measure the resistance of the old wire -- hey, it might have a break in it! -- find out via specs or experimentation how much current is required to open the strike, then work out what voltage and what gauge wire will easily supply twice as much current as required from the voltage source... which must be bulletproof, no pun intended. I'd switch the battery over to a small lead/acid alarm cell if it can open the strike.


Yup.

I assume the keypad is being replaced with the lock, but I can’t be sure of that. Unfortunately I’m being sucked in because it’s a relative. I’d rather not be involved in this, I’m not going to make any money on it. I’m probably going to replace the wire and terminate it and get out

Short test leash worked. Run a long test leash of cat6 and stop waiting for our opinions. Let us know how it works out.

I don’t have the lock to test. I Was asked if I had heavier wire that would help reduce the loss in power. I had no idea the gauge of an old phone wire and figured some here were better at calculating loss and resistance on the wire. Since I can’t just experiment with wire and lock combinations, I thought maybe some other input would be helpful.

You're in a hard position because you're being asked to supply something to solve a problem that nobody knows for sure is the actual problem.

Don't experiment with other wire and lock combinations. Measure the voltages, resistance, and even current that flows when the switch is closed.

I just reread your first post. Being technical for a moment, I've never heard of a " standard 3 line phone cord." What is that?

Do you still have the old lock, or did it get tossed out?


This is interestingly stupid. The current in a simple circuit such as this is identical at every point in the circuit. It's as dumb as seeing a blown incandescent light and saying it's shorted.

Okay, okay, we all know that tech support probably means the voltage at the lock is too low due to the wire having too much resistance.

At this point I'm going to stop, too, and repeat what's been said: have the locksmith man up and make SOMETHING work.

Erine, standard 3 line phone cable would characterize the old Cat3 cable with 3 pair in it. Or older POTS with 2 additional wires (the blue & white, that went with the Red & Green, Yellow & Black). The latter typically was 22awg.


Working with relatives... it always sucks. Seems we always have less patients with relatives than we do our regular customers; doesn't it? :)

I still think my idea of using "audio keypad structured wiring cable" is the best solution. It give you the 16awg 4 conductor for any power requirements you could possibly run into at that distance. And the cat5e for any data connections might need now or in the future.
Surely you have some laying around. I always seem to have 2-3 leftover spools sitting around somewhere, with 20-50 feet on it.

This is what I mean.

[Link: showmecables.com]

The lock and keypad have rj12 connections, and as I understand need six conductors to function. If I could figure out how to put an RJ12 on an 18awg wire, I would do so.