Intercom wiring help

[hightower]

Got an intercom to sort, the pictures speak for themselves I think. What happened was a dog chewed through the cables and some Jack the lad tried to fix it. The ones with orange conductors haven't been touched. The one with a yellow conductor to the terminal has been touched - that is how it is wired since Jack had a go, but whether that's how it was wired before, who knows.

The intercoms can talk to each other I think, it's the ringer system that isn't working. The call button on them does work. Here's the manual too, I'm just on my way out the door to college, but on initial glance I couldn't get my head around it and hoping someone here can help me out.

http://aiphone.com/home/assets/Uploads/downloads/documents/products/instructions/TD-HB Instr.pdf

There's 4 phones in the system.

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[Had8Lives]

According to the manual the C terminals are not supposed to be daisy chained between units. The manual doesn't show linking of any terminals within one unit either.

 

[hightower]

Hmmmm, so I've taken another few minutes to look at this, and I'm not sure it has ever been wired up properly. I've attached photos of how it is currently wired and how it should be wired. Because Office 1 has a link between C, 1, 2, and 3 - I think this has been wired to act as one large intercom without paging individually. I think it's been wired so that you press the CALL button to page every device, and then pick up. Or something along those lines. Does that seem about right?

So if I'm going to get this working how you would expect it to I think I need to adjust the wiring in all devices to resemble my second drawing.

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[hightower]

According to the manual the C terminals are not supposed to be daisy chained between units. The manual doesn't show linking of any terminals within one unit either.

I think that's what was giving me the headache. I've just spent 30 minutes looking at the manual and screaming at the laptop "but it's not f****** wired like that" over and over. The wife was quite amused.

Now I've drawn it out, the conclusion I've arrived at is it's never been wired to work as it should.

 

[The Ghost]

Had to replace a handset the other day, really old the new one was a bit of a brain hurter to figure out. Stick with it you'll do it. After all I thought we are only talking two way communication and buzzer to let in and call up how complicated can it be hey!

 

[Had8Lives]

I would say you are correct in thinking it was never wired right in the first place. You second drawing matches my understanding of the manual.

 

[SparkyChick]

Based on the manual (just looking at the example connection diagrams), it's not wired correctly, with the third handset being way off with all those local links. Your second page shows how it should be wired based on looking at the TD-3H/B sample diagram on page 5 of the manual.

 

[hightower]

Cheers guys. So now it's time for the inevitable:

Me: "I need to adjust the wiring at each intercom to get it working like it should"
Them: "Why? It worked fine before the cables were damaged"
Me: "It couldn't have"
Them: "But it did!"

To be fair, they are very understanding and trusting actually, so hopefully they'll accept what I say and allow me to spend the time putting it right so it can work as it should.

 

[SparkyChick]

Just an observation... based on the oxidation of the copper (unless it's down to lighting) on those first three pictures, the copper of the cores of the cable all looks to be about the same age except the links, the twisting of conductors together for clamping is mostly present (rather than not in photo 3), I just can't see that those links were made by the same guy as the rest of the wiring in the first three shots, which makes me think they are more recent additions. Sure, it could be an alteration done by someone else, but regardless, they are definitely more recent additions than the rest of the cabling.

Clearly matey boy who tried to fix it has joined the new 6 core alarm cable to the existing cables somewhere rather than replacing the whole run as the new colours are only in that one handset. Do those connections match up properly?

The way I see it, there's no way the existing wiring would operate as described in the manual, but I have no clue how the system would work wired as it is with those links removed. Who's to say that with the links removed it won't operate as the client expects? I can't see it myself, but who knows?

The other thought I had was about the CSA of the newer cables. Is there a significant difference between the new and the old? I know from past experience the issues you can have with voltage drop on DC supply circuits even at relatively low currents. Maybe the new is thinner and is creating a sufficient voltage drop to stop the system working?

Who knows, but I'm kind of envious, I like a good mystery

 

[Wilko]

Hmm, agree with @SparkyChick, a new cable not installed by HT ... Perhaps a bit of end to end continuity testing too?

 

[hightower]

Oh, sorry, thought I'd been clear in my OP - there's no doubt about the newer cable in the last picture. Yep, I know where the join is (which I'm going to fix with Jelly Crimps - he only twisted together the cores) but everything is joined through right.

I've got photos of how it is, so I'm going to try the way the manual says when I go back. If it doesn't work I can then put it back to how it is. There's a full voltage on the 'new' cable so no problem with VD, and as I say, it worked fine using the call button when I tried last night.

I don't think the older wiring has been touched, just the newer wiring in the last picture. That's why I don't think it's ever worked as intended, which would speak volumes about the 'spark' that installed it.

It'll be a couple weeks before I'm back, but I'll be sure to update the thread after.

Thanks for all your input.

 

[hightower]

Well as promised I'm back after being to the club, and the news is that I wired it my way (well according to the MI) instead of some bodge it bill's way, and it works a treat. Thanks for your help all.