Subscriber Discussion

How Much Backup Power Needed For 8 Channel NVR / System?

UI
Undisclosed Integrator #1
•Jan 27, 2018

Customer of ours is providing the equipment via their HQ and we are the local folks they've chosen to put the systems in.  Our scope requires a few items including a solution to provide 4-5 hours of backup.

They are providing an 8 channel NVR with embedded PoE ports and the datasheet says 20W but that doesn't count the hard drives.  The 20W spec seems low but that could be because the drives will be the lions share of the power budget, no?

So if we are to specify a 4-5 hour backup that includes the NVR (20W) and 5 (6W) cameras operating on the embedded PoE switch, does an APC unit such as the SMT1500C provide enough?

We are not well versed in the calc. of this yet so any help is appreciated.

Thanks

JH
John Honovich
•Jan 28, 2018
IPVM

#1, thanks for the question. Related, we have UPS Backup Power for Surveillance Guide. I've asked Brian Rhodes to give a direct answer to your question.

MM
Michael Miller
•Jan 28, 2018

I would start by looking at the NVR power supply and see it is rated.  Then I would connect the cameras and get the system working and get a total current draw for the system using a clamp meter or Kill-A-Watt meter.  That is what you going to need to do a UPS calculation. 

Avatar
Brian Rhodes
•Jan 31, 2018
IPVMU Certified

If your total demand was:

20W +30W + 2*9W (HDD W guess here, I have no idea what/ how many you're using) = ~70 Watts per hour

(I have no idea if these demand inputs are true in your case, they seem okay for cameras, but low on the NVR/PoE switch.)

 

However, there's also a bunch of inefficiencies to accommodate for, like heat loss, cable gauge, and length of cables. Then battery temp and battery age also factor into sizing.  Properly accommodating for everything that could be a source of loss turns my brain to mush.

Fortunately, most UPS manufacturers have a product selector. (Here is APC's.) 

Incidentally, given a 5 hour run time and an using a typical inefficient power factor of ~65% percent, APC is recommending you beef up and pick a UPS that supports an additional battery pack.

Checking similar calculators from Minuteman corroborates APC's recommendation.  General pricing is going to range $600 - $800 here, but other variables like number of outlets or input voltage could be a big factor.

See our: UPS Backup Power for Surveillance Guide for more.

 

(1)
U
Undisclosed #2
•Feb 25, 2018

If the NVR is powering the cameras then the NVR should have enough power overhead to compensate for the cabling and recommended cameras.

I would then look at the NVR's specs to get the wattage rating or amp draw rating and plug that into the calculators that most UPS mfgs have.  

Determine how many hours you want the system to run, or determine if you want "gracefull" shutdown after sending out alerts or notifications for power loss.

PS - if you get a RM solution make sure you have space at the bottom of the rack as these units can be heavy! Also be sure you get the correct power plug configurations as these can vary as well. Don't forget about your display and other devices that work with the NVR!

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