Ip camera wattage rating

[pal251]

Bought 5 more eyesurv cameras to add to existing 8 cameras for a customer this week. Bought aZyXEL Fanless 24 Port GbE 170w PoE+ L2 Web Managed Rackmountable Switch GS1900-24HP switch thinking it would power it. Turns out at 11 cameras the switch is over maxed out. Cameras are listed at 5 watts on spec sheet but either the switch or manufacturer is wrong.

Is there a more reliable way to test wattage of cameras? I'm gonna send this switch back or maybe keep it for home and just order 2 more switches for this job. Aggaravating!

 

[fmflex]

Are you able to log into the console of the switch? Does it list the power output of each port?

What do you reckon the chances of using a clamp meter with a small jaw to try measure current draw if all else fails?

 

[pal251]

Yes I logged in. It tells the total usage but I can't find an individual reading for the port.

- - - Updated - - -

I found a poe tester on amazon for 40 bucks I'm gonna buy. Figured I would get two of the 8 port switches from Nelly's and use those.

 

[dryfly]

I have been experimenting with a P4400 Kill A Watt usage meter. Inserting this at the wall socket, I am running a single port 48vdc POE injector to one camera.

If the Kill A Watt meter shows the power supply to the POE injector is drawing 5 watts at 130vac does this mean the camera is also drawing 5 watts at 48vdc? I realize there may be a few ma being used as overhead for the POE injector and PS but I'm thinking it must be close.

 

[PhiDeck]

A well designed and built switching power supply can have efficiency circa 90%. The cable length from injector to camera can also be a factor. Calculating the cable power loss is a pain, as it is a quadratic equation.


Sent from my iPhone using Tapatalk

 

[fenderman]

@pal251
Your issue is related to the default settings of these zyxel managed switches...in the POE settings you need to change the mode to "consumption" instead of the default "classification"..
Classification mode reserves power based on what it thinks the device may need based on the class of the device, not how much it actually draws..
The cameras do in fact draw only about 3-5w or so..
http://kb.zyxel.com/KB/searchArticle!viewDetail.action?articleOid=012309&lang=EN
This explains why it drops off after 11 cameras...The switch is detecting that the camera is a standard af poe device and allocates 15.4w.. 11x15.4=169...so it wont let you add more...
Same will happen with zyxel 8 port 70w managed switches..it will only power 4 cameras until you change the settings to consumption.

 

[40th Floor]

If the Kill A Watt meter shows the power supply to the POE injector is drawing 5 watts at 130vac does this mean the camera is also drawing 5 watts at 48vdc?

Power (watts) = volts x amps

It doesn't make much sense to specify the voltage if you already have watts. The meter you have should have a power factor reading, the difference between what it sees as power and what it sees as volts and amps. So it watts is 5 and power factor is 0.5, you are probably looking a 10 real watts going out. That probably matters to the switch's supply, but not to the $ you pay for "power" (you pay for 5w and use 10w).

And like someone wrote, there's the loss in AC to DC (so more power used at the wall than the camera is taking).

What you might want to do, assuming you can't bypass the POE by plugging your camera into a wallwart which is easy to measure alone, is get a low-power POE camera and killawatt that. Compare that reading, including power factor, to the main camera.

Just testing a Hik 2032

w/ LEDs 4w PF 0.55

no LEDs 3W PF 0.45

That's on a wallwart.

P.S. To answer your question, if you mean the difference between the camera connected to the cableand not is 5 watts, then sure, close to that. Take two readings, one with the camera, one without.The difference is close to what the camera alone is taking.