Video door phone Experts

[Anthony5]

I have a video door phone with 2 screens inside. I'll include a wiring diagram, but since it is from China you will have to understand that outdoor is actually indoor and vice versa and "Black" = power supply

 

Currently I have some issues with the wiring at the outdoor unit which was a substandard job and I'm redoing it.

 

Same as on the diagram there are 2 power cables ( actually 1 cable with 4 wires) going to the outdoor unit, both carry 15V.

 

Does it really need 2 separate power supplies for the video part and the main part, or can I just use 1 and split at the unit?

 

Reason I ask is because if this is possible I can use one set of wires in the wall as the door lock wires, since the initial wires for the lock have rotted away, and it is quite impossible to pull a new set.

 

Second question is, the door lock is in my case the gate motor, which has a a connection for remote door lock. Does in this case Magnetic lock or Electronic lock applies?

 

 

 

 

 

 

[Anthony5]

Really nobody who can advice if I can split a single power feed at the outdoor unit, or if I really need 2 separate feeds?

 

Right now there are 2 feeds as there are also 2 separate connections at the power supply, but both carry continuous 15V, so I don't really see the purpose for dual feed.

 

 

 

[RichCor]

15V, but are they both AC or DC and at what wattage?

 

Most likely a poor design.  One reason for using the multiple lines is for current carry capacity as you can get vast voltage drops over small wires with long runs.

 

But if you are willing to experiment, and possibly sacrifice the entire system, then you may want to try powering it with just 2-wires and a heftier (larger amperage) power supply. 

[Anthony5]

8 hours ago, RichCor said:

15V, but are they both AC or DC and at what wattage?

 

Most likely a poor design.  One reason for using the multiple lines is for current carry capacity as you can get vast voltage drops over small wires with long runs.

 

But if you are willing to experiment, and possibly sacrifice the entire system, then you may want to try powering it with just 2-wires and a heftier (larger amperage) power supply. 

 

I actually have been experimenting, and this is the result I got.

 

The manual says that system uses 0.2 W in standby and 5W when operating.

 

My powerline is 4 x 0.5mm over a distance of about 25 meter. There is a junction box at the bottom of the wall where the 2 feeds arrive and 2 sets of wires go up in the wall to the unit.

 

If I use 1 feed on 1 set of wires there will be no video signal. When I use 2 feeds on 1 set of wires I'll have video but no sound .

 

When I use 2 feeds each to their dedicated wire set, it will work properly.

 

I receive 15.4V at the wall on each power feed, I have no idea how to measure the current at the end point.

[RichCor]

Hmm. I would think you should be able to get away with just using 6 of the 8 wires specified, condensing 4 wires carrying power to 2 wires feeding both sides of the wired circuit    ...and it should work unless they are doing special signalling over the 2 discrete power wire pairs (where combining then would mess with the segregated signaling).

[Anthony5]

8 hours ago, RichCor said:

Hmm. I would think you should be able to get away with just using 6 of the 8 wires specified, condensing 4 wires carrying power to 2 wires feeding both sides of the wired circuit    ...and it should work unless they are doing special signalling over the 2 discrete power wire pairs (where combining then would mess with the segregated signaling).

The black" video signal power ground" and black "video power ground" wires are internal connected, as I can measure with a multimeter.

 

The strange thing to me is that it's the audio part doesn't work properly, as I would have expected that it would have been the video part.

[maxpower]

On 12/3/2016 at 8:38 AM, Anthony5 said:

 

I actually have been experimenting, and this is the result I got.

 

The manual says that system uses 0.2 W in standby and 5W when operating.

 

My powerline is 4 x 0.5mm over a distance of about 25 meter. There is a junction box at the bottom of the wall where the 2 feeds arrive and 2 sets of wires go up in the wall to the unit.

 

If I use 1 feed on 1 set of wires there will be no video signal. When I use 2 feeds on 1 set of wires I'll have video but no sound .

 

When I use 2 feeds each to their dedicated wire set, it will work properly.

 

I receive 15.4V at the wall on each power feed, I have no idea how to measure the current at the end point.

 

You made the whole system take on feed correct ?

[Anthony5]

4 hours ago, maxpower said:

 

You made the whole system take on feed correct ?

 

 

Not sure what you mean, as I said earlier, there are 2 feeds going from the power supply to the junction box in the perimeter wall, from there are 2 x 2 wires going up to the outdoor unit.

First I tried 1 feed connecting to 1 set of wires going from the junction box to the unit, and connected grey/red to on wire and black/black to the other wire.

 

In that case the unit got activated but I didn't get video signal indoors.

 

Next I connected both feeds to the single set of wires going from the junction box, and in that case I would get video signal but no audio.

[maxpower]

My diagram shows the whole system supplied from one power source leaving the second disconnected. Is this what you tried, or did you only supply part of the system (one unit) with a single source. If you supplied only one unit with a common source, this might explain why you are missing audio or video depending which power source was used. You really do need to connect everything to the same common source to test this properly. 

 

[Anthony5]

Yes that is what I tried in the first step, but then I would have no video signal.

In the second step I used both power sources, but only a single set of wire going from junction box to outdoor unit.

 

In the second step I would have video signal but no audio.

 

In the diagram, outdoor should read indoor and vice versa.

 

There is only 1 outdoor unit and 2 indoor units in my system.

 

The issue is with the outdoor unit.

[maxpower]

15 minutes ago, Anthony5 said:

Yes that is what I tried in the first step, but then I would have no video signal.

In the second step I used both power sources, but only a single set of wire going from junction box to outdoor unit.

 

In the second step I would have video signal but no audio.

 

In the diagram, outdoor should read indoor and vice versa.

 

There is only 1 outdoor unit and 2 indoor units in my system.

 

The issue is with the outdoor unit.

The use of two supplies at each unit is strange but must have been done for a reason. Most systems use a 4 wire link to the outdoor modules which carry power video and audio. A separate supply is then used for lock release via volt free contacts at the outdoor unit.

It is possible that lock release and call data is on one of the supply lines.

[Anthony5]

But I use both supplies. I combine the feeds, and at the outdoor unit both connections get power from both feeds.