Wire Test

imalwayshappy · 23-04-2018 8:10pm #1

Hi All,

My cctv stopped working and I want to buy a multi meter to test if the wire is damaged/shorted. My question is I can only test one side at a time using the multi meter as the cabling is long and runs through the house (which I don't want to have to remove just to test both ends at once) how do I test this with access to one side of the cable at a time. I have looked on you tube however I cannot find anything on this situation.

Many Thanks

cletus · 23-04-2018 8:17pm

Simplest thing I can think of is a length of wire the same length as the one you want to test, connected to the far end and run back to the multimeter. Obviously check continuity on this first.

Be aware, depending on the length of the run your testing, you'll have to take resistance of the wire into account

Max Moment · 23-04-2018 8:19pm

imalwayshappy wrote: »

Hi All,

My cctv stopped working and I want to buy a multi meter to test if the wire is damaged/shorted. My question is I can only test one side at a time using the multi meter as the cabling is long and runs through the house (which I don't want to have to remove just to test both ends at once) how do I test this with access to one side of the cable at a time. I have looked on you tube however I cannot find anything on this situation.

Many Thanks

Can you cross two of the cores at a time at the far end of the Cable and use the continuity function on the meter to verify Cores are intact. Might not be the most scientific approach if it’s CAT 5 or 6 cable though

mickdw · 23-04-2018 8:21pm

Twist 2 cables together at one end then test for continuity across the same 2 wires at the other end.
Repeat with different wires to narrow down faulty wire if no continuity when tested.

mickdw · 23-04-2018 8:21pm

Twist 2 cables together at one end then test for continuity across the same 2 wires at the other end.
Repeat with different wires to narrow down faulty wire if no continuity when tested.

gctest50 · 23-04-2018 8:23pm

Take down the camera and plug it into the DVR or whatever with short cables

Works now ? probably cable/connectors

Doesn't work now ? probably camera ( or that channel on the dvr is dead )

imalwayshappy · 23-04-2018 8:48pm

gctest50 wrote: »

Take down the camera and plug it into the DVR or whatever with short cables

Works now ? probably cable/connectors

Doesn't work now ? probably camera ( or that channel on the dvr is dead )

Thanks all for the replies. Whats funny is 4 cameras are connected to a dvr and all 4 went down at the same time. When i plug a camera into the dvr without the 4 way splitter the camera just clicks and the leds just blink red theres no picture. I wonder has a power surge or something have knocked out the cameras and the wires. I have surge protection on the plugs though.

gctest50 · 23-04-2018 9:18pm

Is there a separate PSU for each camera ?

imalwayshappy · 23-04-2018 9:28pm

gctest50 wrote: »

Is there a separate PSU for each camera ?

No its one power supply with a four way splitter connected. Each camera is connected to the splitter.

my3cents · 23-04-2018 9:28pm

OP what makes you think 4 cameras stopped working at the same time and not the base unit?

imalwayshappy · 23-04-2018 9:32pm

my3cents wrote: »

OP what makes you think 4 cameras stopped working at the same time and not the base unit?

I played back the recordings and they all went down with a few seconds of each other. The cameras irs have gone and there is a clicking sound from the camera. I have an unused camera which i plugged in using the existing cable and the irs just blink (not solid). Its all very strange...

gctest50 · 23-04-2018 9:36pm

You need to test the power supply

my3cents · 23-04-2018 9:36pm

Any chance this is a problem with the PSU used for the cameras?

imalwayshappy · 23-04-2018 9:49pm

my3cents wrote: »

Any chance this is a problem with the PSU used for the cameras?

Maybe, however i have tried testing one of the cameras directly connected to the power supply (with a new cable) and the camera clicks with the flashing Ir's. No signal on the monitor. I know the cable is fine along with the dvr as i used the same setup with a new camera and it worked fine. I just dont get how four cameras can just get knocked out. I could understand one camera getting a fault but not all four.

my3cents · 23-04-2018 9:55pm

I ask about the psu as if it can't supply the full voltage or current necessary apart from erratic operation or failure you sometimes get clicking and flashing lights (LED's) because the system draws power gets just enough then as it takes more than the psu can supply the voltage drops and it switches off then it all starts again.

imalwayshappy · 23-04-2018 10:00pm

my3cents wrote: »

I ask about the psu as if it can't supply the full voltage or current necessary apart from erratic operation or failure you sometimes get clicking and flashing lights (LED's) because the system draws power gets just enough then as it takes more than the psu can supply the voltage drops and it switches off then it all starts again.

Thanks for this. Its a good shout. I might get a meter and test it and revert. Many thanks

my3cents · 23-04-2018 10:09pm

imalwayshappy wrote: »

Thanks for this. Its a good shout. I might get a meter and test it and revert. Many thanks

Sometimes (often even) a bad psu will test out with a meter and show the correct voltage but as soon as there is some current drawn when you plug in a device the voltage drops as the psu fails.

So what I am saying find a way to check the voltage with at least one device connected.

wexie · 23-04-2018 10:13pm

If it's network cable rather than coax just buy a cable tester?

2 pieces, one on either end?

https://www.ie.screwfix.com/philex-network-cable-tester.html?utm_source=Google&utm_medium=CPC&utm_campaign=Shopping&gclid=EAIaIQobChMIxa_r-afR2gIVDp3tCh1NeA4GEAQYASABEgLlNfD_BwE&gclsrc=aw.ds

can't help with coax, not my thing

Nevermind, I see you're past the cable stage

Wire Test

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