New install - Cabling advice needed

[jst3712 0]

Hi guys. I recently purchased from eBay a DVR that came with 4 cameras and cabling. The cables are 18 meters long each, BNC/DC power combo type. Also a single power supply, 12VDC 2A with a 4-way power splitter.

1) What are your thoughts on these, what seem to be, low-cost cables?

2) Is it a good idea to run 4 cameras off the same power supply?

3) Is it not recommended to upgrade the power supply to a higher amperage one (e.g 2A to 5A) considering the long cables?

4) With the power supplies, do the cameras work best with unregulated, regulated or switchmode power supplies? I don't know how sensitive these cameras are, but I've been advised mine are all CMOS based.

Thanks.

[jst3712 0]

No replies? Wow.

[gb5102 0]

1) What are your thoughts on these, what seem to be, low-cost cables?

2) Is it a good idea to run 4 cameras off the same power supply?

3) Is it not recommended to upgrade the power supply to a higher amperage one (e.g 2A to 5A) considering the long cables?

4) With the power supplies, do the cameras work best with unregulated, regulated or switchmode power supplies?

Here is my opinions:

 

1. Junk, more than likely...you want CCTV-grade RG59 or RG6 for video(or cat5 with QUALITY baluns), and for power cables it depends on the distance and power draw of the cams

 

2. No, unless each output is individually fused and your cameras have isolated the video ground from the power ground(or you will likely introduce ground loops/interference). Your cheap 12v eBay cams do not have isolated grounds...I don't even need to know what brand/model they are...

 

3. No, length of cables has nothing to do with amperage of power supply. Voltage drop under full load(IR on) is what you need to be concerned with. The proper way to address voltage drop is to run the correct size power cable, but you can also buy power supplies that allow you to boost the VOLTAGE to compensate.

http://www.supercircuits.com/resources/tools/voltage-drop-calculator

 

4. You want regulated...switchmode power supply will always be regulated, transformer-based power supply can go either way

[jst3712 0]

1) What are your thoughts on these, what seem to be, low-cost cables?

2) Is it a good idea to run 4 cameras off the same power supply?

3) Is it not recommended to upgrade the power supply to a higher amperage one (e.g 2A to 5A) considering the long cables?

4) With the power supplies, do the cameras work best with unregulated, regulated or switchmode power supplies?

Here is my opinions:

 

1. Junk, more than likely...you want CCTV-grade RG59 or RG6 for video(or cat5 with QUALITY baluns), and for power cables it depends on the distance and power draw of the cams

 

2. No, unless each output is individually fused and your cameras have isolated the video ground from the power ground(or you will likely introduce ground loops/interference). Your cheap 12v eBay cams do not have isolated grounds...I don't even need to know what brand/model they are...

 

3. No, length of cables has nothing to do with amperage of power supply. Voltage drop under full load(IR on) is what you need to be concerned with. The proper way to address voltage drop is to run the correct size power cable, but you can also buy power supplies that allow you to boost the VOLTAGE to compensate.

http://www.supercircuits.com/resources/tools/voltage-drop-calculator

 

4. You want regulated...switchmode power supply will always be regulated, transformer-based power supply can go either way

 

Hi, sorry, I haven't been checking this lately. Thanks for your advice. Yeah, I agree that the stock standard cables that came with the system were cheap and nasty. I have since changed all of my (unshielded) cables to shielded RG-59 CCTV type (video & power in 1 still; surely better than what I was using previously) and also upgraded the power supplies from 12VDC 2A to 5A to avoid using too many individual power supplies (your mentioning of separate fuses has been noted). I still have everything temporarily laid out on a large workbench, so haven't installed the system as yet. So far haven't seen any performance issues *Touch wood*