Is a <1 second chirp/buzz every 5 seconds normal?

[Ogham_apc]

This was originally posted on APC forums on 4/14/2011

---

Hi,

Can anyone tell me if it is normal for a Back-UPS (Model BR550GI) to making a short (<1 Second) chirping/buzzing sound at a regular (approx. 5 second) interval whilst powered on and fully charged (no load)?

The buzz is relatively quiet - but noticeably louder than the very quiet constant humming/buzzing that the unit makes.

Any information/guidance would be greatly appreciated!

Thanks,

Ogham

Message was edited by: Ogham

[sunnyville_apc]

This was originally posted on APC forums on 4/15/2011

---

Yes I do imagine that the electronics are nearly identical - it can proide a different wattage though.

[sunnyville_apc]

This was originally posted on APC forums on 4/15/2011

---

Hi, just to clarify, I have a BR1500GI not a 550, so slightly different model. However the buzzing is exactly as you describe it, roughly 5-6 seconds apart, the timing stays the same. It is slightly audible over the standard buzzing sound the unit makes.

[BillP]

This reply was originally posted by Angela on APC forums on 4/14/2011

---

did this just start or develop over time? generally, if you have to ask if a sound is normal, its not. maybe its a vibration?

[Ogham_apc]

This was originally posted on APC forums on 4/15/2011

---

I just wanted to add a few details:

When the unit is powered off (but still being supplied by the wall outlet) there is no sound whatsoever.

When the unit is initially powered on and it does a ~10 second self test the buzzing (for those ~10 seconds) is much louder than both the 5 second interval chirp/buzz and the constant background hum.

[Ogham_apc]

This was originally posted on APC forums on 4/14/2011

---

Hi,

It is a brand new UPS, I would expect a constant humming - but the slightly louder buzz every 5 seconds seems a bit odd to me.

If it is a vibration, it is definitely not from an external source. I've got the unit in a silent room with everything turned off at the moment.

Ogham

Message was edited by: Ogham

[Ogham_apc]

This was originally posted on APC forums on 4/14/2011

---

Do you mean a vibration caused by the transformer?

I found a post which described similar symptoms, and possibly the cause (last post - Phil_D):

[http://forums.apc.com/spaces/4/back-ups-surge-protectors/forums/general/4114/rs800-every-3-seconds-c...]

Quote : "Once the battery is fully charge it will be quieter, just making a little chirpy buzz once every couple of seconds you can hear if you put your ear near it. When it switches to battery, for a self test or power outage, then goes back online, the buzzing will increase as the battery is topped up again.

It is simply the intelligent charging circuitry regulating the voltage and current to recharge the battery, and it is using a switch mode power supply and some form of Pulse Width Modulation to control voltage which makes it sound different to usual mains hum we are familiar with from transformers."

Could this be what I am experiencing?

[sunnyville_apc]

This was originally posted on APC forums on 4/15/2011

---

Just thought I'd add my 2 cents - I have a BR1500GI - it does the same buzzing thing while on and plugged into the mains power (fully charged) - It is barely audible though unless every other device in the room is switched off.

[Ogham_apc]

This was originally posted on APC forums on 4/15/2011

---

sunnyville,

Thanks very much for letting me know that!

Just to confirm, you have the same approx. 5 second interval buzz/chirp (on top of the background hum) ?

Mine is pretty quiet also (a lot quieter than the buzz that kicks in when the UPS self tests), It stands out because all of the kit in this room is pretty silent anyway.

I've been getting quite worried about this, if you have the same thing happening and your BR550GI is functioning normally - I am much less inclined to worry and can probably treat this as normal for this unit!

Cheers, Ogham

[Ogham_apc]

This was originally posted on APC forums on 4/15/2011

---

Ah, I guess the electronics are identical - I imagine it has just got a larger battery..

Thanks for clarifying sunnyville! 🙂

[BillP · Accepted solution]

This reply was originally posted by Kevin Mychal on APC forums on 2/10/2012

---

So this is normal?