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Wire Size for Security Camera

KAC

Nov 17, 2021
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I'm helping a friend install a camera system (NVR and 4 wireless cameras). House is older and fairly difficult to get into the attic (and install power for cameras). The house has vinyl siding for the soffets - I'm thinking about just using 16 gauge drop cords to run power to each camera and then tie them all together on the garage side of the house. One run is about 80 feet - the others are about 40 feet. Does anyone see a problem using 16 gauge drop cords (I'm thinking the power draw is very small since the cameras are 12v with a 110v male connector and a transformer for 110v to 12v DC)?
 

crutschow

May 7, 2021
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Does anyone see a problem using 16 gauge drop cords
The cameras should have a power rating in their specifications, but the power draw is likely quite small (a few watts).
18Ga wire should be sufficient, even for the 80 foot run.
 

Tha fios agaibh

Aug 11, 2014
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16 Does anyone see a problem using 16 gauge drop cords (I'm thinking the power draw is very small since the cameras are 12v with a 110v male connector and a transformer for 110v to 12v DC)?

Yes. Power circuits should be installed according to your local electrical codes.
If these are 120v branch circuits you need to run a minimum of 14awg regardless of the load and use a chapter 1 wiring method according to the NEC.

You can't use flexible cord as a substitute for a permanent wiring method.

If this is a power limited DC circuit on the load side of a transformer, the smaller wire is probably fine, but it still must follow the installation rules (see NEC art 725)
And use the proper cable (Example be listed and marked CL2 for class two wiring)
 

kellys_eye

Jun 25, 2010
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If the cameras are indeed 12VDC then I would avoid using 'local' AC power packs and feed them from a DC source closer to the DVR. Most 'shotgun' video cables take 12VDC/video and the DC side of it is pretty light gauge stuff - indeed I fit a CCTV system at home by using old CAT5 cable as the feed, doubling up some cores for the longest runs (80ft) which, even then, wasn't strictly necessary.

Running an AC supply means following 'code' as to the type of cable, the termination and protection etc not to mention the connection at the source....

Most modern CCTV cameras (unless they run heaters) draw <10W (so under 1 amp) and CAT5 (or similar) is a simple and readily available option.
 

ChosunOne

Jun 20, 2010
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If you re-post your question on this forum,
https://www.doityourself.com/forum/electronic-home-security-systems-alarms-devices-87/
you can get an answer from a professional tech who actually works with security video systems.

I'm an alarm tech myself--in spite of marketing hype, security alarm systems and security video systems are different animals--but I've worked with enough 12V video systems to know that wiring to the cams is usually low voltage and not subject to Code that covers AC line power (as kellys_eye said). But I'd recommend you post your question to the DIY forum above, which is specific to security systems.
 

Tha fios agaibh

Aug 11, 2014
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I've worked with enough 12V video systems to know that wiring to the cams is usually low voltage and not subject to Code that covers AC line power (as kellys_eye said).

That's not true here in the States.

Class 1 line power and class 2 power limited circuits have have different requirements but are still subject to code.

Whether you want to follow code rules is another matter.
 

ChosunOne

Jun 20, 2010
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That's not true here in the States.

Class 1 line power and class 2 power limited circuits have have different requirements but are still subject to code.

Whether you want to follow code rules is another matter.

I stand corrected, Tha fios agaibh. I was drawing on my own 40+ years of professional experience of working with low-voltage systems for different companies, mostly alarm systems but also a little bit of access, video, intercom systems, and even phone lines and doorbells. I'd always assumed that since no license was required to work on these systems in MD, VA, and DC, that it wasn't regulated by code; so I never looked into it before.

I was right about not needing a license to install and service low-voltage wiring in alarm systems, but when I looked into it in the last couple of days, that has changed now. Requirement to work on low-voltage systems vary a lot now because the "low-voltage" umbrella covers a variety of different systems that were not thought of as being related before. There is still no national standard for low-voltage wiring. It's apparently Balkanized worse than the alarm industry, with different state, county, sometimes town requirements.

As it happens, I did have to get "certified" about 30 years ago (1990-1991 IIRC), officially Registered in VA and Licensed in MD, to work on alarm systems; but I never associated the required training, state and national background check twice (once each for both states), and certification with electrical code because it didn't include anything about wiring safety--nothing relevant to fire or shock hazard (which is approximately zero in my line of work). For instance, it's general knowledge in my industry that 18 AWG is preferable for running power from a class 2 16.5VAC plug-in transformer to the control panel, but it's also common practice to use 22/4 cable and twist two 22 AWG wires together for each leg. I know it's still not as good (but perfectly adequate for short runs) as using an 18 AWG pair, but a lot of techs don't--because it's nowhere in the training, which isn't about electrical standards, it's almost entirely about proper installation & service to avoid false alarming, which was becoming epidemic and driving police and fire departments crazy by the mid-'80s; which is the primary, if not sole, reason that states decided they had to regulate the alarm industry in the first place. The state agencies in my area handling the training and enforcing compliance were the Department of Criminal Justice Services in VA; and State Police in MD. (Did I mention the regulation was Balkanized?)

So I never associated it with electrical code requirements. I retired around 2010, and let my license and registration expire after that, so I haven't done a refresher in about 10 years, so I have to admit my experience is out of date. It's possible they teach class 2 power limited circuit code now, for all I know. But I doubt it, since it was never about electrical code.

Not related to the original subject, but as an afterthought:
As it happened, the required training, registration, and licensing did significantly reduce the false alarm rate in the early '90s---but not for the reasons one might suppose. Sometimes our classes were taught by instructors who knew less than most of us experienced techs. I can't think of anything I actually learned in any of the required courses, although it's possible that some of the newer techs did.

But in the '80s, the alarm business was booming and lucrative, and attracted a lot of 'trunk-slammers"--guys working out of the trunks of their cars, who could get an alarm system installed profitably, but not properly. They'd typically make a lot of money for awhile, installing a lot of 'trash' systems (sometimes the components were good, but the installation was crappy), then disappear when enough customers started calling for the inevitable service needed. The reason I knew about it was because a lot of their customers finally gave up on them and called an established professional dealer, and I would inherit the mess.

When VA and MD started regulating the industry, they actually enforced the regulation--when police responded to an alarm, they made note of the installing and servicing company, and made sure they were licensed/registered. It got too expensive and troublesome for trunk-slammers when they actually had to run a regulated dealership, and the false alarms dwindled.

I personally hated the extra hassle of getting my license and registration, but I have to admit: As fouled up as the regulation was, it did serve its purpose.
 

Tha fios agaibh

Aug 11, 2014
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Most of my experience is in controls but I'm also a licensed master electrician.
Yes, it can be a hassle. Electrical codes can be confusing and often misinterpreted. Every few years there are dozens or code changes and additions to keep up with.

The NEC does not specifically say "low voltage" other than an IEEE reference which basically says anything under 1000v.

When people are talking about "low voltage" they are usually talking about power limited energy circuits.

There are 3 classes of PL circuits but CL2 is deemed essentially safe except for some classified areas such as where it could spark an explosion.

Let's be honest, if some hack installs a camera or a doorbell wrong that's supplied from a CL2 source, no one is probably going to die even if it's shorted out.

With circuits like this, it not really about the voltage, it's the fact that it's power limited which makes CL2 circuits intrinsically safe.
CL2 circuits are limited to 100va.

With that said, hazards can still exist.
For example, If the wrong wire or cable is used, the insulation can become toxic when burned, especially if routed through a plenum or return air duct of HVAC system. A small fire could kill everyone in a house in minutes by breathing toxic fumes.

If the wrong wire size is used it may cause an undesirable voltage drop to the equipment, but it won't cause a shock or fire hazard unless ran along with other non power limited circuits. There are rules to keep these different class circuits away from each other.

I certainly wouldn't want to have my telephone wiring ran in conduit along with line conductors.

Class 2 circuits are rightfully not under as much scrutiny as line power circuits but there's definitely rules and safe practices that need to be followed to insure a safe installation.
 
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