IP Cameras

[sii]

This week I am going to have to install some IP security cameras in our facility. I've been putting this off for some time now, but it's time to bite the bullet. The camera mounts in a thermoplastic housing which is temperature controlled and has a metal base. There is a a circuit board mounted inside the housing which requires 24 VAC, 25 watts max. The camera is then fed from this circuit board and requires 4 watts max.

I have 120 VAC available and am going to mount a transformer in a continous hinge enclosure in the IT room and feed each camera through it's own EMT from there. I am going to bring an Ethernet cable into the enclosure and connect it to a switch in order to branch out to each camera seperately, in effect making this a main control panel for all of the cameras.

I have 2 questions:

1: Each camera will be individually fused on the secondary side of the transformer. Can I put a 30mm key switch in the circuit for each camera, between the fuse and camera, so that each can be serviced without disruption of the others?

2: Is there anything prohibiting me from running the Ethernet cable in the pipe with the 24 volt circuit? Each housing will be grounded back to the control panel.

 

[sii]

IP Cameras

I posted this on the EE forum but got no replies.

This week I am going to have to install some IP security cameras in our facility. I've been putting this off for some time now, but it's time to bite the bullet. The camera mounts in a thermoplastic housing which is temperature controlled and has a metal base. There is a a circuit board mounted inside the housing which requires 24 VAC, 25 watts max. The camera is then fed from this circuit board and requires 4 watts max.

I have 120 VAC available and am going to mount a transformer in a continous hinge enclosure in the IT room and feed each camera through it's own EMT from there. I am going to bring an Ethernet cable into the enclosure and connect it to a switch in order to branch out to each camera seperately, in effect making this a main control panel for all of the cameras.

I have 2 questions:

1: Each camera will be individually fused on the secondary side of the transformer. Can I put a 30mm key switch in the circuit for each camera, between the fuse and camera, so that each can be serviced without disruption of the others?

2: Is there anything prohibiting me from running the Ethernet cable in the pipe with the 24 volt circuit? Each housing will be grounded back to the control panel.

 

[augie47]

I hope you get a more qualified opinion than mine, but based on Art 725, it would appear that your power supply is a Class 1 and you can not install the ethernet cable in the same raceway. If you could power the unit from a transformer marked Class 2, it would be permissible.
Take the above with a grain of salt as Art 725 is not m y forte'.

 

[jumper]

Have you purchased the cameras yet? You can get 12vdc cameras and power them with the ethernet cable to each camera.

 

[dbuckley]

Can the heater accept 24VDC? If so, I'd have thought a POE ethernet hub and a 24V "splitter" at the camera would be the answer. You'll have to look around to find a splitter and a hub that'll do more than 25W but they do exist... Worst case is that you'd need an injector fronting the hub.

 

[hbiss]

The 24VAC to each camera is primarily for the housing environmental heating and cooling. Secondary is powering the camera.

How many cameras? Sounds to me like one or two cameras per transformer is the way to go. That way, and be sure you use a CL2 or CL3 transformer, you can run your power wiring with your CAT5. You could also do away with all the fuses and key switches.

-Hal

 

[MAK]

Would it not be easier to just buy a 8 or 16 channel power supply to feed the camera's enclosure power?
Altronix makes a bunch of stuff for this kind of application.http://www.altronix.com/

 

[nakulak]

I reread article 830, and I am wondering if this does not apply to your situation ?

also, 725.26 B 1 (2005)- if your power supply meets the limitations of class 1, and is functionally associated, then the power supply conductors are allowed in the same raceway.

 

[sii]

I already have the cameras...actually the IT department bought them. I've only seen the specs. They also purchased a power over IP injector but were unable to make it work dependably.

The housing heat/cool system accepts only AC and has a terminal block specifically for feeding the camera, althought the camera DOES accept AC or DC. It just seemed like it would be easier to feed each assembly with only two wires (not counting EGC) instead of feeding the cam and housing seperately. Each run is roughly 150' from the hub.

How many cameras? Sounds to me like one or two cameras per transformer is the way to go. That way, and be sure you use a CL2 or CL3 transformer, you can run your power wiring with your CAT5. You could also do away with all the fuses and key switches.

I can't remember, four or five cams. Sorry, I have no low voltage experience, I was hoping to use the key switches as a means of disconnect although I don't think it is required. Do you have a code reference for the Class 2 or 3 transformer requirement?

I suppose I don't need the individual fuses per cam, it just seemed like a good idea to prevent the entire system from going down in the case of a problem. The location of the cameras has been specified by management and they are in areas where they are pretty much gauranteed to be damaged, either by a forklift or "inadvertant" blow from a hammer.

 

[nhfire77]

Go POE. Simplify. Each camera really really really should be fused independently. This is standard practice. Also you don't have to use 12vdc. You can use a power injector that is rated for 24vac. This is done all time. Try looking into NVT network video tech. Expensive? Yes but the have everything and you can then find a
cheaper brand if needed. There is no benefit to key switch disconnects, just fuse each camera power lead/injector seperately.

If severe damage is expected look into extreme CCTV, now a
Division of Bosch. They make a heavy duty camera for that kind of situation. Also consider using a varifocal lens and mount it out of the reach of the "hammer"

 

[augie47]

I reread article 830, and I am wondering if this does not apply to your situation ?

also, 725.26 B 1 (2005)- if your power supply meets the limitations of class 1, and is functionally associated, then the power supply conductors are allowed in the same raceway.

I think that's power supply & Class 1, but does not include his ethernet.

 

[nhfire77]

I think that's power supply & Class 1, but does not include his ethernet.

Optically isolate the router with fiber, mount it in an enclosure= ethernet cable + class 1 circuit together safely.

 

[hbiss]

I agree with PoE. I don't know why you are having a problem with it. Well, ok I do know- it's your IT geniuses. Don't bother with power inserters, do it right. Use a PoE switch that puts power on it's ethernet ports to the cameras. Not a lot of money either. Also with that few cameras I would simply use individual transformers for the housings.


Do you have a code reference for the Class 2 or 3 transformer requirement?


There is no code reference, CL2 or CL3 should simple be printed on the transformer.


In short I think you are making a big deal out of this. IP cameras are the easiest to install. Basically you just plug them into the network and go to a computer to look at it.

-Hal

 

[recthree]

i installed a similar setup last year.i believe the switches are a good idea.i just had a jbox at each location(to avoid flying splices) and free aired my wires.it would be hard to break the joints without at least a moment interuption but they do pop back onto the network pretty quickly.

as for sharing the conduit,while the insulation would be rated for it,you may still have interference.

 

[hbiss]

it would be hard to break the joints without at least a moment interuption but they do pop back onto the network pretty quickly.

That's why you use PoE for the cameras and a separate plug-in wall wart transformer for the housing heating and cooling. Don't make this more complicated than it needs to be.

-Hal

 

[jrdsg]

agree with hal

agree with hal

poe for the cams, seperate lv power for the heaters.