Re: Ground Loop challenges

[ABLE1 <someone@xxxxxxxxxxx>]

On 1/26/2018 1:58 PM, Bob La Londe wrote:
> On 1/21/2018 6:36 AM, ABLE1 wrote:
>> On 1/21/2018 4:36 AM, doug wrote:
>>> "ABLE1" <someone@xxxxxxxxxxx> wrote in message
>>> news:9jO8C.314017$%g5.8315@xxxxxxxxxxx
>>>> Hey Guys!!
>>>>
>>>> I have a camera install that is plagued with Ground Loop issues.
>>>>
>>>> I have been installing individual BNC Ground Loop Insulators on
>>>> individual
>>>> cameras that are the worst which cleans up the video for that camera.
>>>>
>>>> However, over time another camera gets bad, and then another, etc.
>>>>
>>>> As I understand the problem is due to an imbalance in voltage at 60
>>>> cycles
>>>> or ground reference between phases from the power company. And that the
>>>> video is very sensitive to the imbalance and causes the video bars, bla
>>>> bla bla.
>>>>
>>>> My questions are as follows.
>>>>
>>>> Is there a something device thingie that can be installed at the
>>>> breaker
>>>> panel across the phases that can blend or sync the cycles, etc.??
>>>>
>>>> Is there a something device thingie that has more than one
>>>> individual port
>>>> that can be mounted at the head end (like a 8 or 16 port) that can
>>>> isolate
>>>> the ground loop with out using all the dongles??
>>>>
>>>> Thanks for any insight!!
>>>>
>>>> Les
>>>
>>> Is this coax or cat 5 using baluns?
>>> Are the cameras 12vdc or 24vac?
>>> Are you using a single power source or individual power sources for each
>>> camera?
>>>
>>> Doug
>>>
>>>
>>
>> Sorry, I forgot to mention that important info, brain was not totally
>> activated.
>>
>> There is a single power source 120vac for everything with two 16
>> channel 24vac power supplies for the cameras.
>>
>> A few cameras are 24vac but most are 12vdc with a step down inverter at
>> those cameras.
>
> I thought an inverter turned DC into AC.  I had bad luck with those
> AC/DC converters on cameras a while back, and never used one again.  I
> have used several cameras that were AC DC auto switching internally that
> seemed to work just fine, so maybe I just had cheap converters.
>
> I did try a fairly expensive multi tap ground loop isolator at the DVR
> once a long time ago.  It worked but all the camera feeds were grey and
> dim.  Loop termination on and loop termination off at the dvr.  Both
> were the same.  I went to cheap single line ground loop isolators at the
> cameras after that and they seem to work just fine.
>
>

Hi Bob,

I guess maybe the term "inverter" could be the wrong term for this
device and you are most likely correct that an inverter is changing
DC voltage to AC voltage.

Maybe the correct term that should have used would be "converter" where
the voltage is being converted from 24VAC to 12VDC.

In some respects it may just be which side of the Continental Divide you
are standing on.  :-)

As things always seem to go nuts at the worst possible time, I am
presently having a problem with one camera that seems to be blowing
the "converter" at the camera.  It is either the camera is pulling to
many amps when the IR kicks or something like that.  It is a new camera
and still under warrantee.  I just ordered another and before I install
I will be taking some volt/amp readings so I can compare values.  Also
ordered some new "converters" since I am out of stock.

Have a good weekend.

Les