Map Security Posted June 22, 2007 Share Posted June 22, 2007 I'm getting many conflicting opinions regarding sending 12v power down shotgun cable.... some disties are telling me the max length is 50m wilist others say 200mtrs....I guess there are cheapo cables and higher quality stuff - Is this the difference? In you opinion what is a safe length?? I tend to you 8/16 channel PSU with varible O/p upto 13.8v Link to comment Share on other sites More sharing options...
arfur mo Posted June 22, 2007 Share Posted June 22, 2007 I'm getting many conflicting opinions regarding sending 12v power down shotgun cable....some disties are telling me the max length is 50m wilist others say 200mtrs....I guess there are cheapo cables and higher quality stuff - Is this the difference? In you opinion what is a safe length?? I tend to you 8/16 channel PSU with variable O/p upto 13.8v it will depend greatly on the current to be drawn by the camera model used, as this will affect the degree of voltage drop (no 240 mains down this cable PLEASE! - and yes i have seen it done;) ) the power pair is i think is rated @ 3 amps, personally on long runs i would plump for fitting a local psu as near the camera as possible, makes for a single cable and far easier to handle. for the coax side appx 200 meters is about all you will get before images start to get affected, and will depend again on if there is any local interference sources on the route. regs alan If you think education is difficult, try being stupid!!!! Link to comment Share on other sites More sharing options...
Map Security Posted June 22, 2007 Author Share Posted June 22, 2007 The cams I'm looking at take 500mA with IR and the longest run is about 100m Ideally I'd like to run all 10 off the same PSU.....I know this is possible but is it good practice? Link to comment Share on other sites More sharing options...
arfur mo Posted June 22, 2007 Share Posted June 22, 2007 The cams I'm looking at take 500mA with IR and the longest run is about 100mIdeally I'd like to run all 10 off the same PSU.....I know this is possible but is it good practice? i'd guess you'd be safe over that distance, not keen in all eggs in one basket off the one psu. if you going to do this use separate fuses to each camera, so if you get a short on one it won't kill all the others. having a single PSU will mean if you have to boost the voltage for a distant camera's needs, the nearer ones will be working above the normal limit's so be careful. should a 'local' camera fail or is disconnected all the voltages will be increased to the remaining ones due to the lessoned load on the PSU, this could damage them - so food for careful thought me thinks Yoda. edit just to add, if you use a single large PSU and it later fails it will be relatively expensive to replace within the year for you, or the client out if warranty so could cause bad feelings, where as an individual small psu will be very cheap in comparison and readily available, keeping spares on the van is also eased while the other camera's will remain operational. regs alan If you think education is difficult, try being stupid!!!! Link to comment Share on other sites More sharing options...
whistle Posted June 22, 2007 Share Posted June 22, 2007 Why not fit 24 V cams then you should be ok at 100m only just. We would never go over 50m with 12v Link to comment Share on other sites More sharing options...
spider Posted June 22, 2007 Share Posted June 22, 2007 I'm getting many conflicting opinions regarding sending 12v power down shotgun cable....some disties are telling me the max length is 50m wilist others say 200mtrs....I guess there are cheapo cables and higher quality stuff - Is this the difference? In you opinion what is a safe length?? I tend to you 8/16 channel PSU with varible O/p upto 13.8v Hi, It depends on if the power cables are 0.5mm or 0.75mm the calc is roughly; 100m of 0.5mm= 8.02 ohms ; 500mA x 8.02 = 4.01 volt drop therefore only 9.77 volts at the camera after 100 metres with an input voltage of 13.8v 100m of 0.75mm = 4.94 ohms ; 500mA x 4.94 = 2.47 volt drop therefore only 11.33 volts at the camera after 100 metres with an input voltage of 13.8v I have used a 24vAC 8 output PSU individually fused before with no problems Good luck Hope this helps Link to comment Share on other sites More sharing options...
alterEGO Posted June 22, 2007 Share Posted June 22, 2007 Why not fit 24 V cams then you should be ok at 100m only just.We would never go over 50m with 12v agreed, local power for us all the time now, very good if you need to swap/upgrade a camera with higher draw. as for coax, cant remember the last time we used it, we run cat 5e for all commercial jobs now, with local psu. 1 cat 5 per camera so great for future add ons. also started using cams with the built in baluns. Link to comment Share on other sites More sharing options...
Map Security Posted June 22, 2007 Author Share Posted June 22, 2007 lots of great advice....and its very very appreciated indeed I will certainly use a couple of "local" supplies! guys Mat Link to comment Share on other sites More sharing options...
alterEGO Posted June 22, 2007 Share Posted June 22, 2007 agreed about local power but i prefer coax every time. with regards to video signal. :!: agreed, but cat5 is so good to work with. Link to comment Share on other sites More sharing options...
camerabloke Posted June 22, 2007 Share Posted June 22, 2007 yep, cat 5 for me Eucam Security Systems 0845 4630 746 www.eucam.co.uk Link to comment Share on other sites More sharing options...
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