So I have a slight concern about the CyberPower BRICs BR1200ELCD UK.

 

I have been running a couple of simulations to test a power outage and when the UPS goes into running on battery there is a buzzing sound coming from the UPS when it is running on battery power only also even after Unraid has shutdown after the allotted time it senses the UPS is on battery power.

 

If I turn the PSU for my Unraid server off the buzzing sound stops, also the buzzing sound is louder when the PSU has ECO mode switched on.

 

As I've never had a UPS, I'm just wondering if this is normal.

 

When I do a test power outage Unraid reports the power draw as 108w (ECO mode on) and 115w (ECO mode off) 

 

I've tested a couple of other devices printer & router and there is no buzzing sound. I only intend to have the Unraid server and my broadband router connected to the UPS permanently.

 

Uraid server specs:

Prime A320M-K motherboard

Ryzen 3 3200G

8GB ram

EVGA 550W SuperNOVA

2 x Seagate IronWolf 12TB NAS

1 x Seagate IronWolf 6TB NAS

1 x WD 500GB M.2 

 

Thanks

Normal. The simulated sine wave is "dirty" compared to mains.

What power supply are you using that has an "ECO" mode?  I've never heard of that.

nevermind. didn't know evga made power supplies.

 

As @jonathanm said, you're probably hearing various transformer vibrating when put under load.  All my APC units have a distinct "hum" to them when they're on battery power; it's the transformer in the inverter coming under load, and the plates in it are vibrating.  Every transformer does it, just better/expensive ones do it less.

 

You could possibly be hearing an interaction between the transformers in the PSU and UPS, such that they're "beating" against each other electrically (feedback), due to the "Simulated Sine Wave Output" on the UPS.

  

Edited May 15, 20215 yr by sota

It is normal when UPS in battery mode, a big transformer were inside the UPS ( thats why UPS usually quite heavy ). The buzzing increase with the loading.

16 hours ago, sota said:

didn't know evga made power supplies. 

They don't make them.

In North America EVGA used to market and sell PSU's made by Super Flower.

Now that the exclusive  marketing deal is over Super Flower now sells and market PSU's under its own name.

Edited May 16, 20215 yr by Lolight

Thanks guys, appreciate the advice.

 

Though I rarely have the power go out where I live I wanted to make sure that if it does for any period of time the Unraid server will shutdown properly.

 

The only minor concern I have is that when Unraid server is shutdown when on battery, there is still the buzzing sound like server is still drawing power for some reason.

 

But the UPS is doing the most important thing that I need it to do, so I can live with that.

4 hours ago, BynotB said:

The only minor concern I have is that when Unraid server is shutdown when on battery, there is still the buzzing sound like server is still drawing power for some reason.

Modern computers draw power even when shut down, so they can react to an event to boot up.

The ATX power supply has included +5V standby supply since inception.