Using POE NVR without providing power

D

d5775927

Getting comfortable
Dec 11, 2019
465
427
Israel
Hi,
I have a cat5e cable run that was installed a decade ago, I suspect the cable is not of high quality (however, in iPerf speed test I get 890 to 950 Mbps), it also got chewed by rats so, I connected it (wire by wire).
It was hard to install the cable since it connects to far parts of the house and travel through very tight spaces (and in an interior wall).
I want to use the cable for powering a Dahua camera, however, I have electrical socket near by, so I don't want to pass power over the Ethernet cable, just data, power will be supplied using the camera power plug.

How can I ensure the NVR doesn't try to send power to the camera, can I remove some wires (out of the 8) on the NVR end.
The cable is terminated in T568B standard on both ends.

My plan is to add a female to female Ethernet plug, then crimp a new cable (to connect to the NVR) with some wires missing, so the NVR will not be able to send power.

1. Is that possible?
2. Is that possible to use POE splitter to install 2 cameras on the other end (both not using power from the Ethernet cable)?
 
d5775927 said:
How can I ensure the NVR doesn't try to send power to the camera, can I remove some wires (out of the 8) on the NVR end.
The cable is terminated in T568B standard on both ends.
Click to expand...
You don't need to do that drastic measures you can just add non POE switch in between NVR and camera

d5775927 said:
My plan is to add a female to female Ethernet plug, then crimp a new cable (to connect to the NVR) with some wires missing, so the NVR will not be able to send power.

1. Is that possible?
Click to expand...
Possible - yes, needed - no - look above ^^^^^^^

d5775927 said:
2. Is that possible to use POE splitter to install 2 cameras on the other end (both not using power from the Ethernet cable)?
Click to expand...
Yes you can, I am using one PFT1300 @EMPIRETECANDY sells them
 
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d5775927 said:
Hi,
I have a cat5e cable run that was installed a decade ago, I suspect the cable is not of high quality (however, in iPerf speed test I get 890 to 950 Mbps), it also got chewed by rats so, I connected it (wire by wire).
It was hard to install the cable since it connects to far parts of the house and travel through very tight spaces (and in an interior wall).
I want to use the cable for powering a Dahua camera, however, I have electrical socket near by, so I don't want to pass power over the Ethernet cable, just data, power will be supplied using the camera power plug.

How can I ensure the NVR doesn't try to send power to the camera, can I remove some wires (out of the 8) on the NVR end.
The cable is terminated in T568B standard on both ends.

My plan is to add a female to female Ethernet plug, then crimp a new cable (to connect to the NVR) with some wires missing, so the NVR will not be able to send power.

1. Is that possible?
2. Is that possible to use POE splitter to install 2 cameras on the other end (both not using power from the Ethernet cable)?
Click to expand...

And why you want to do it like this?

You can disable POE power on switch or NVR on this port...

Also if you provide power to camera using camera power-in cable, it should switch to it automatically (ignore POE)..
 
steve1225 said:
there are 'POE power blockers' on the market.. or some stupid cheap ethernet switches..

cutting wires in CAT5 cable don't work - POE power can be sent over the same wires (1,2,3,6) as fast ethernet data..
Click to expand...
Yes that is correct however
  • Mode A (Data Pairs):
    The power is sent over the same pairs used for data, specifically pins 1, 2 and 3, 6.

  • Mode B (Spare Pairs):
    The power uses the "spare" pairs, pins 4, 5 and 7, 8.

  • 4-Pair Mode:
    Advanced PoE standards can use all four twisted pairs to deliver higher power levels.
 
Jahua95 said:
Yes that is correct however
  • Mode A (Data Pairs):
    The power is sent over the same pairs used for data, specifically pins 1, 2 and 3, 6.

  • Mode B (Spare Pairs):
    The power uses the "spare" pairs, pins 4, 5 and 7, 8.

  • 4-Pair Mode:
    Advanced PoE standards can use all four twisted pairs to deliver higher power levels.
Click to expand...

Many times I added second camera in place where I had only 1 CAT5 cable - by splitting 1,2,3,6 and 4,5,7,8 pairs into two separate plugs on both ends (always connected as 1,2,3,6)..
Works like two separate CAT5 cables plugged to two separate POE switch ports - the only limitation is that FastEthernet speed - gigabit requires all 8 wires..

Works very well, zero need to POE splitters or POE-IN/POE-OUT switches..
 
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d5775927 said:
My plan is to add a female to female Ethernet plug, then crimp a new cable (to connect to the NVR) with some wires missing, so the NVR will not be able to send power.
Click to expand...

Jahua95 said:
Mode A (Data Pairs):
The power is sent over the same pairs used for data, specifically pins 1, 2 and 3, 6.
Click to expand...
POE switches use Mode A. I'm sure there's an exception somewhere, but I've never found one. Standalone injectors are the ones that use Mode B.
 
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