Very White Image on Analog cameras

[support.st 0]

Hi all

Please, excuse me for my poor English

I need your Help.

I have a big problem with an analog cameras installed in a seawater desalination plant. on some cameras I have a very white image (see attached image)

I installed : 38 analogue cameras (Messoa SCB267) + 3 Samsung 1654 DVR + on line UPS Liebert GXT3 5 kVA + a KX100 armored coaxial cable .

A common 220 VAC power supply (without earth) is installed then it split up to power on each camera, then there is a 24VDC power supply into enclosure to power the camera and fan.

The very white image doesn't have relation with camera’s settings or lens.

On one side I have 5 cameras: C1 (400 feet), C2 (600 feet), C3 (900 feet), C4 and C5 (800 feet)

The cables of cameras are installed together in underground sheaths over a distance of 400 feet (until C1) then they split up: C1, C2 and C3 on the one direction and C5 and C4 on the other direction

On the first common 200 feet I had to install the video cables near a high voltage cable (distance 3-4 feet)

At the beginning there was the problem (white image) on C1, C2 and C3 only (C4 and C5 were OK) . To solve the problem I installed a video converter (coax to FO to coax) and the problem was solved but some hours after C4 and C5 have become also white.

I have the same problem on other direction: 3 cameras were very white , I install the coax to FO converter , the 3 camera became OK but two cameras became white.

The video converters and FO are very expensive and a I can’t install another one.

Note : I have a camera with over 1100 feet coaxial cable an it’s working fine.

Thank you for your time,

[support.st 0]

Hi all

This morning I made a new test : in the control room , I connect my camera (with white image) directly on my small BNC monitor ... it works very fine " title="Applause" />

I connect the same camera on my DVR , the image is very white

my DVR doesn't have a BNC output so I'm using a 40" VGA monitor

All my systeme is earth grounded (on-line UPS , DVR , ....)

the Small BNC monitor is powred with earth throw my USP

but the 40" VGA monitor doesn't have a ground

can this probleme (white image on some cameras) be caused by non earthed monitor ?

 

thank you

[support.st 0]

Hi evry one ,

Well, I did an other test : I connect my (white) camera on DVR , and earthed BNC Monitor connected to the DVR ...

result : white image.

Is threre somthing wrong between the DVR , the UPS , the earth ?

 

help please

[the toss 0]

Your picture is ok where it enters the DVR (as shown by your test monitor) so that would suggest the problem lies with your DVR or VGA monitor. Swap them out to prove which is the culprit.

 

It looks more to me that your auto iris is stuck in the open position

[support.st 0]

Your picture is ok where it enters the DVR (as shown by your test monitor) so that would suggest the problem lies with your DVR or VGA monitor. Swap them out to prove which is the culprit.

 

It looks more to me that your auto iris is stuck in the open position

 

Thank you the toss for you reply

the test of the white image gives the same result on the three DVRs

if I use the same input with other cameras it works fine

I connect a BNC earthed monitor to the DVR ....it gives the same result (white image)

It seems like electrical problem or grounding problem