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Power Question for CCTV?

Power Question for CCTV?

Power Question for CCTV?

I ran some Siamese RG59 cable 18/2 for power. Used a 24VAC 16.8 AMP power supply mounted to the wall and plugged into outlet. The cameras run on 12VDC or 24VAC. Their power consumption is

Power Consumption 6W (12VDC); 5.5W (12VDC); 5.5W (PoE)

The longest camera is about 500 feet and it's not getting power. I DO NOT want to run the cable again because it too 10 hours and 2 people. Should the cable and power supply be sufficient for the distance?


RE: Power Question for CCTV?

There are a few other variables, but in rough cut terms I expect you are dropping about 3 and half volts or a bit less. Try a volt meter at the camera end both with and without load and check.

A voltage more than 10 percent below rating is generally a problem for cctv camera, which puts you in rough cut terms at least one volt below minimum function threshold.

The starting power demand for many cctv cameras exceeds its running power which is on the name plate, so your initial drop could be much greater and that may prevent the circuitry, especially on a higher end camera, from completing the "power up" process.

A work-around, although not the best way to deal with this, is to look at the capacity of your wire size. Your 18 awg wire is still able to carry more amperage than what your demand requires, but it is a bit small relative to voltage drop. Get a variable output power supply, or a 28 volt AC power supply, and mark your cable ends at every junction as being 28 volt.

By upping the starting voltage, your camera end voltage, even with load, should fall within spec and end up around 24 or 25 vac at the camera end.

However, before jumping to this, I suggest doing the load, and no load, tests at the camera end to be sure that there are no other issues in play.

RE: Power Question for CCTV?

Quote (upinflamezzz)

Power Consumption 6W (12VDC); 5.5W (12VDC); 5.5W (PoE)
Hoping this is a typographical error...
Is there a jumper on the camera that selects which power you're providing? Many have this... Make sure the camera works at the power supply to be sure there isn't something other than the cabling that is awry.

RE: Power Question for CCTV?

Power Consumption 6W (12VDC); 5.5W (12VDC); 5.5W (PoE)
I saw the same thing and thought it was a typo because where's the VAC watts, but that's what's on the box. Also, I thought there may be a jumper too and couldn't find one.

I got the closest camera catch power today. For some reason my rg59 cable feels thicker on a couple off rolls, but it's all 18/2 standard.

How far should the power and video run with a 24VAC PS and 18/2 for power?

RE: Power Question for CCTV?

How far should the power and video run with a 24VAC PS and 18/2 for power?

You need to figure the load at termination to answer this properly, however, using some rough figures, about 350 to 375 ft., allowing for not more than 10% voltage drop and standard 24 VAC fixed supply.

I still suggest taking load and no-load readings at the camera termination and be sure you only have a voltage drop issue.

Other issues may be present, what is the current limit on your power supply, per port? Are you dealing with fuses or self-resetting limiting devices? You specify total capacity of the supply, but if the ports are limited, you may have zero voltage at the camera as soon as the load is applied, but may show voltage at no load. If there are any splices, are they tested? Did you very the termination of the power connector? Did you pre-test the camera to ensure it does, in fact, have an internal switching power supply and can run off of 24vac ? Did you signal test the coax cable and the coax terminations to ensure that if the camera is working, you will receive the output signal ?

RE: Power Question for CCTV?

Quote (upinflamezzz)

How far should the power and video run with a 24VAC PS and 18/2 for power?

IF (if) power consumption is 6 watts, then you should see a 1.6 volt drop across a 500' span of 18/2. Assuming power supply is REALLY delivering 24VAC, you'd see 22.4VAC at camera. The power supply is likely providing more than 24VAC, so I doubt the cable loss is your issue.

RE: Power Question for CCTV?

Do you have a voltmeter?
Can you post links to the specs for the camera and power supply?

RE: Power Question for CCTV?

The Altronix power supply is the one I use. For the longer runs, I bump it up to 28VAC to compensate for the voltage drop.

Depending upon the camera, the input is either auto sensing for voltage, or there are separate terminals for AC & DC connectivity. Double check the installation guide for details.

Is the camera you are feeding fixed or PTZ? If the remote camera is a PTZ, often time the power draw when being moved is quite high. I had a camera that rebooted each time we tried to rotate it. It was near the end of the limits on voltage drop and it was right on the edge. Bumping the power supply to 28VAC fixed the issue until we could get 120VAC power to the camera location.

RE: Power Question for CCTV?

Thanks for all the help. I think it's my cable. I bought 3 boxes of VIV RG59 Siamese cable off Ebay a while back and this is the cable giving me the trouble. The power wires feel thinner compared to the 3 boxes I bought off of Amazon last week. I found the ends of of both and tested and the thicker cable from Amazon gets power over 800' away while the other cable does not. The VIV box is not marked, but isn't all RG59 cable 18/2? I'm going to try the Altronix power supply as a simple fix and use the other power supply with good wire in my other building. This may work and will save me a lot of time than re-running those 4 cable lines through the rafters and getting crazy dirty in process.

RE: Power Question for CCTV?

Buying from eBay is a crap shoot. If you have NO power at end of the in-place cable, a different power supply won't help.

RE: Power Question for CCTV?

"isn't all RG59 cable 18/2?" - NO


RE: Power Question for CCTV?

Gee, pull up a ten year old post to make a point - and irrelevant as it take a lot more skill to link switches in a "stack" that pulling and verifying a cable.

I've learned a couple things along the way:
1) always verify at least basic functionality on a cable run before closing up the ceiling and putting away your ladders.
2) You're spending lots on labor, so get quality parts and do it right the first time.

Frankly, I don't know if I would have caught the 22 gauge vs 18 gauge issue, and I do buy a lot of stuff from ebay. Most of what I pull is 50-100 ft phone / Ethernet, but for multiple 500 ft runs I wouldn't skimp on the cable.

At this point you basically have 2 options - use the existing sub-standard wire as a pull string to feed new cable along the existing route, or add a power supply close to the cameras.

Whatever you do, you're still going to have to get to the far end of at least one wire to verify that the camera works with a local supply and if you plan to use the coax half of the Siamese, that it will pass a decent signal.

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