Technical Questions for Back-UPS Pro Units

[Anonymous user]

Hello APC,

I've just acquired an APC BR1200G and after the fact I got it I realized about a couple of things which I didn't consider. I would like to know whether you can confirm this for me so that I know I got things right.

1- The total supported wattage for the model I bought is 720W. When I connect my devices to the 'surge only' outlets but nothing to the 'battery backup' outlets the 'Load capacity bar'is empty. Is it then correct to assume that the total advertised wattage support is only for the backup outlets? Which means that when buying an UPS you only need to sum the appliances you will need to connect to backup outlets? 

2- Let's say my home experiences a short or even long abrupt change in Voltage, will the devices connected into the 'surge only' outlets be protected against it? or only those connected to the backup (battery)? More over: What are the differences between the backup and surge outlets, besides the obvious battery support form the first one?

3- The product documentation states that this UPS generates a 'Step-approximated sine-wave'. Could you please confirm whether this only happens on battery mode? Or is generating that wave all the time, even when power is in good shape? Bottom line, when no electrical problems are detected by the unit, is the UPS taking the pure sine wave directly from the AC wall outlet and sending it to all my devices? regardless of which UPS outlet they are connected to?

4- I own very expensive studio monitors and after reading a lot it seems that the advise is to connect these to the surge outlets and not to the backups. This is then related to the previous item, I honestly don't want to be sending a stepped simulated sine wave to my speakers, so should I connect these into the surge protectors only and let the speakers take the outage? What is APC's recommendation on this?

I hope I'm not asking for too much but I've invested a lot of money in my home studio and I want to make sure I'm doing things right.

Thanks a lot for your time and support.
Best regards,

[BillP]

Hi Javier,

1) Correct

2) The devices in the surge only side will be protected from a surge or spike - long or short under/over voltages will effect this load.  The devices in the battery backup side will transfer to battery should the device find the incoming voltage unacceptable during a under/over voltage.

3) The step-approximated sine wave is only generated when on battery.  When not on battery, the pure sine wave from AC power is passed to your load.

4) We do not have a recommendation based on this - you would need to consult the manufacturer of your devices as we do not know how this equipment would react to a step approximated sine wave.

If you are worried about the step-approximated sine wave, we would recommend a smart-ups unit for more sensitive equipment.

Regards,

[BillP · Accepted solution]

Javier,

2) A spike would be a very significant increase in voltage with the potential to damage your load while a under/over voltage is a small deviation from 120v which is much more tolerable but not necessarily healthy if sustained over very long periods of time (this is something your electrical company works to avoid).

6) The noise is normal, I can hear mine under my desk if the office is quiet.  I would point you in the direction of K-Base article FA176155 (while this is for Smart-UPS units, most of the article applies for Back-UPS

7) A higher sensitivity means your unit will transfer to battery more often with smaller variations in the incoming power quality.

😎 Very possible - I am no expert on your PSU but higher quality PSU's do expect pure sine waves and adverse effects can take place such as buzzing or a load drop.  I notice a buzzing sound from my home desktop when on battery, but looked into it upon purchase to make sure it was not an issue.  This is definitely something I would consult your PSU manufacturer on just to make sure the buzzing is just an annoyance more than a harmful effect on the PSU.

Regards,