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Max Cable Length Using Shotgun Cable


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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

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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!!!!

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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?

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!!!!

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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

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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.

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hi guys,

with cctv going over to Cat5e, will there be a time that wired intruder go's this way?

think for a moment about the advantages,

1) the cable comes in bigger 305 meter rolls.

2) also in easy feed one man boxes,

3) unlike our beloved stranded which the roll cheeks fall of after bouncing down the stairs spewing a tangled mess.

4) crimpingh plugs on is a doddle (once you can remmember the colour code for the wire map).

5) the meters are ace at testing all 8 cores at once and giving a measurement to fault

the plugs are possibly the weak point, but then the worlds computers run on them with seemingly few issue's, even though they aslo have to contend with MS Xp

could be a bit saucy to sort out on a concealed contact, but hey thats what j/b's were made for and grade 3 contacts are big enough to have an in and out socket.

regs

alan

If you think education is difficult, try being stupid!!!!

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hi guys,

with cctv going over to Cat5e, will there be a time that wired intruder go's this way?

think for a moment about the advantages,

1) the cable comes in bigger 305 meter rolls.

2) also in easy feed one man boxes,

3) unlike our beloved stranded which the roll cheeks fall of after bouncing down the stairs spewing a tangled mess.

4) crimpingh plugs on is a doddle (once you can remmember the colour code for the wire map).

5) the meters are ace at testing all 8 cores at once and giving a measurement to fault

the plugs are possibly the weak point, but then the worlds computers run on them with seemingly few issue's, even though they aslo have to contend with MS Xp

could be a bit saucy to sort out on a concealed contact, but hey thats what j/b's were made for and grade 3 contacts are big enough to have an in and out socket.

regs

alan

possibly, but as for cable getting tangled ect. am i the the only one who uses cable dispensers?

http://cgi.ebay.co.uk/CABLE-REEL-CARRIER-A...1QQcmdZViewItem

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possibly, but as for cable getting tangled ect. am i the the only one who uses cable dispensers?

http://cgi.ebay.co.uk/CABLE-REEL-CARRIER-A...1QQcmdZViewItem

We use the same for outdoor cabling, but use this for indoor (no excuse for tripping over this :rolleyes: )

http://www.super-rod.co.uk/kablemate.pdf

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possibly, but as for cable getting tangled ect. am i the the only one who uses cable dispensers?

http://cgi.ebay.co.uk/CABLE-REEL-CARRIER-A...1QQcmdZViewItem

no, but they don't stop the cable from running on then spilling over the cheeks.

in a domestic (my market) you lucky to get your tool box in the passage let alone a cable depenser.

regs

alan

If you think education is difficult, try being stupid!!!!

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Sooner or later EVERYTHING will be run over CAT5. But then again I reckon sooner or later everything will be IP based.

The opinions I express are mine and are usually correct!

(Except when I'm wrong)(which I'm not)

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Agreed, but you know its going that way, everyone wants integrated systems and a single structured cabling solution.

The opinions I express are mine and are usually correct!

(Except when I'm wrong)(which I'm not)

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Guest anguscanplay
Agreed, but you know its going that way, everyone wants integrated systems and a single structured cabling solution.

i thought there was lots of talk in the cctv community of starting to run your own backbones to keep it away from the " in - house " it guys

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i thought there was lots of talk in the cctv community of starting to run your own backbones to keep it away from the " in - house " it guys

Agreed.

Nobody in their right mind would install a security system with IT having access to the patch panels.

Also:- it will be some time yet before high end CCTV goes over to IP due to transmission costs, and is unlikely to use CAT5E cabling. Building protection CCTV is another matter but see above.

Ilkie

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