how to wire cctv into ac dc
Discussion
How long is the cable run from the power supply to the cameras?
If that power supply in the photo was powering all 6 cameras then there isn't a lot of copper so hopefully the cable run is only short. Keep in mind that the previous system ran 24 volts, your new cameras are 12 volts so twice the current and more chance of voltage drop.
I don't like the look of the cable used for the power. As far as I can see they Blue, green and Black have been combined for one side of the power, Red, Orange, yellow & white for the other. There is a cable run down to the first camera then another cable joined with the same colour pairing to go off to the next camera. It means that first cable has to take the strain for all 3 cameras (I think you said there were 3 cameras on each pole).
Depending how powerful your new cameras are (I'm not sure what distances you are wanting them to cover) I forsee voltage drop problems. If you find you can't get cameras to work try powering them locally with the transformer and an extension lead. If they work then the problem is voltage drop between the power supply and the cameras.
If you have 3 cameras on each pole I would suggest a 4 camera 5 amp power supply for each set of 3 cameras, something like this: https://www.cctv42.co.uk/shop/cctv-accessories/cct...
You can either do away with the 4 way splitter if the single cable to power all cameras works or run pure copper CAT5 to each camera and use it for video and power. We suggest 1 pair for video, 3 pairs for power.
Once again, how long is the cable run from power supply to cameras ?
Henry
If that power supply in the photo was powering all 6 cameras then there isn't a lot of copper so hopefully the cable run is only short. Keep in mind that the previous system ran 24 volts, your new cameras are 12 volts so twice the current and more chance of voltage drop.
I don't like the look of the cable used for the power. As far as I can see they Blue, green and Black have been combined for one side of the power, Red, Orange, yellow & white for the other. There is a cable run down to the first camera then another cable joined with the same colour pairing to go off to the next camera. It means that first cable has to take the strain for all 3 cameras (I think you said there were 3 cameras on each pole).
Depending how powerful your new cameras are (I'm not sure what distances you are wanting them to cover) I forsee voltage drop problems. If you find you can't get cameras to work try powering them locally with the transformer and an extension lead. If they work then the problem is voltage drop between the power supply and the cameras.
If you have 3 cameras on each pole I would suggest a 4 camera 5 amp power supply for each set of 3 cameras, something like this: https://www.cctv42.co.uk/shop/cctv-accessories/cct...
You can either do away with the 4 way splitter if the single cable to power all cameras works or run pure copper CAT5 to each camera and use it for video and power. We suggest 1 pair for video, 3 pairs for power.
Once again, how long is the cable run from power supply to cameras ?
Henry
this is turning into a nightmare! So if I ran new cable then is there any specification i need? I may as well run new coax and power.
OK if i run new cable I guess il buy the adaptor you mentioned in your previous link.
And the cable - is there a maxium length I need to stick to?
something like this
http://www.ebay.co.uk/itm/100M-SHOTGUN-RG59-2-CORE...
OK if i run new cable I guess il buy the adaptor you mentioned in your previous link.
And the cable - is there a maxium length I need to stick to?
something like this
http://www.ebay.co.uk/itm/100M-SHOTGUN-RG59-2-CORE...
Edited by wjwren on Monday 8th February 20:45
OK.
That's a long cable run, I would be really surprised if you don't suffer voltage drop particularly with the somewhat crappy cable being used for power. There is a significant difference between 12 volts DC and 24 volts AC.
I think you are going to end up powering the cameras locally. Where is the nearest 240 volts to the cameras?
Before you get too involved give me a call tomorrow. I will have a look at your site over the internet whilst we have a chat about what you are wanting the system to do. There might be a different way to skin your cat.
Henry
That's a long cable run, I would be really surprised if you don't suffer voltage drop particularly with the somewhat crappy cable being used for power. There is a significant difference between 12 volts DC and 24 volts AC.
I think you are going to end up powering the cameras locally. Where is the nearest 240 volts to the cameras?
Before you get too involved give me a call tomorrow. I will have a look at your site over the internet whilst we have a chat about what you are wanting the system to do. There might be a different way to skin your cat.
Henry
You have 6 cameras which require 12VDC < 1 amp each. So a total of 6 amps. So you'll need a 12VDC - 6A power supply.
But, as you've found out, the cable run is long and you'll get a voltage drop, so you might need to up the voltage, say to 15VDC to compensate. You'll need to test with a volt meter at the cable ends.
Test with one camera, the one with the longest cable run, use one of you new PSU at the head end, see if it works and what voltage drop you get.
Or, as you've suggested, rewire with the shotgun cable and use a multi-output PSU like the one you originally linked to.
Or, power the cameras locally, but this can be a pain.
But, as you've found out, the cable run is long and you'll get a voltage drop, so you might need to up the voltage, say to 15VDC to compensate. You'll need to test with a volt meter at the cable ends.
Test with one camera, the one with the longest cable run, use one of you new PSU at the head end, see if it works and what voltage drop you get.
Or, as you've suggested, rewire with the shotgun cable and use a multi-output PSU like the one you originally linked to.
Or, power the cameras locally, but this can be a pain.
Edited by megaphone on Tuesday 9th February 09:00
wjwren said:
ok ive just measured the furthest distance using google earth and if i put it straight across the roof which is single storey flat it's 145ft
Get a multimeter and measure the voltage at the furthest point. I've got 8 cameras running off a 2A 12v supply over RG59 "shotgun" cable - i have cameras that are on the end of at least 40 meter runs working without issue.
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