Is there a downside to plugging my equipment into battery backup? (1 Viewer)

[Josh Wolfman]

Is there a downside to plugging my equipment into battery backup instead of directly into an outlet? The house I am living in does not have grounded outlets (only renting so feel no need to upgrade this). I have a Liebert battery backup from my server room at work- it kept a Dell server up with a switch for an hour. I was thinking about plugging my 36XBR800, B&K preamp, and Aragon 8008X3 into it. What do u guys think?

 

[Chuck Kent]

You need to know what the CONTINUOUS current output capability is on your backup. (Some of these units can only run for short term duty cycles.) Then add up the current needs of your connected components (NOT the output wattage but the input amperages (usually found next to the power cords.))

My guess is that you might be ok except for the Aragon 8008. It probably pulls too much...

 

[Craig F]

Also, make sure the unit outputs a sine wave.

 

[Josh Wolfman]

What is a sine wave?

 

[Steve Owen]

What is a sine wave?

This page has a diagram of sine waves and square waves. It is what the voltage looks like at your AC (alternating current) outlet. Many battery backups (Uninterruptible Power Supplies, or UPS) do not output a pure sine wave. They often output a square wave, a modified square wave, or a clipped square wave. A PC power supply can deal with that, but chances are your audio equipment may not behave properly if it sees an output like that.
There -are- UPS's available that produce a pure sine wave output, but they're not the cheap ones that you can find at your local computer store.
-Steve

 

[Bill.P]

A Sine Wave:
http://hyperphysics.phy-astr.gsu.edu...sou/wavvar.gif
When input power fails and the UPS kicks in, the UPS will either output a square wave, a modified sine wave, or a true sine wave. Most UPSs either output a square or a modified sine, since it is alot cheaper to design, and the computer power supply doesn't care. Computers have switching power supplies, which simply rectify the AC and create a bulk DC bus of a few hundred volts. Noise here doesn't matter.
Audio amplifiers, on the other hand, use a linear power supply. The linear supply is designed to filter a small range of frequencies (i.e. 60Hz). If there were hundreds of harmonics as in a square wave, everything else would pass through to the output, and into your audio.

 

[Gabriel_Lam]

Depending on the output of your Liebert, the 36XBR800 and the Aragon might be a bit too much. What's the VA or wattage rating on it (or at least the model number)?

I have my H/K AVR8000 receiver (110w/channel, 694 watts maximum power consumption w/2 channels driven) plugged into a Compaq T2000 UPS unit (2000VA, 1400 watts, true sine wave output) and it works very well. Nothing else is plugged into it though.

 

[Josh Wolfman]

Thnaks for the replies! I will look in the morning at the model number and post it.

 

[Chu Gai]

out of curiousity, why do you want to do this?

 

[Josh Wolfman]

To protect my equipment...ever see what a surge or sudden loss of electricity does to electronics? Not good. Also, i have this UPS just sitting around- might as well use it if I can.

 

[Chu Gai]

i most certainly have, and the fact you have no ground to speak of renders your approach next to useless. if you want to protect your equipment and don't want to spend a lot and furthermore, your grounding issues are highly suspect, there are better approaches for under 100.

 

[Chu Gai]

the effectiveness of a surge protector is somewhat dependent in part on its ability to absorb some of the energy from a surge and then to effectively channel what it can't deal with into the ground. now the further your equipment is from ground, the less effective any unit out there will perform. for those that've seen some of the pictures of fried surge protectors, you've seen examples of both poorly designed ones and most definitely undersized ones.
since you're renting, and you've got no ground you need an approach that'll provide protection under these adverse conditions. rather than what you're using, more effective would be a unit that employs silicon avalache diodes. a unit that would meet your needs both now and in the future would be something like the DPS Plus series from www.transtector.com and it goes for something like $85. It's also got some EMI/RFI filtering like everyone else which is good. You have to order directly from the company. The SAD approach is fast, it'll absorb all your typical transients without any degradation, and in the eventuality that a killer surge comes through, the unit will fail in an open position. What that means is that the unit will not allow anything past it. Contrast that to MOV based units which do not necessarily fail in an open situation.
If you're going to use the Liebert, i'd certainly contact them and inform them of your present wiring situation and find out how the unit performs under that scenario. I've a feeling, that the unit's specifications and performance criteria depend to a large extent on you, the user, having suitable wiring.

 

[Josh Wolfman]

Thank you for the informative reply. I will look into that.

 

[IraSWeiss]

I am using a UPS on my systems for one reason:

When we lose power momentarily (~ 1 second average 2x month), I lose the volume I set on my digital cable box and possibly VCR programming.

I am only backing up the Cable Box and VCR with APC equipment, everything else is surge protected with a Monster Power 2500 or 1000.

Ira S. Weiss

 

[Chu Gai]

I can certainly appreciate that approach Ira, it's just that when your ground is suspect and renters always fall into that situation, one needs to take more proactive approaches. Also, it never hurts to contact the company and try and speak to an engineer who can answer your questions. That's next to impossible with Monster...Panamax is a little better...with regards to Transtector I can only say I had no problems speaking to an engineer.

 

[Josh Wolfman]

I have a Liebert GXT RT1500-120. Does anyone know for sure what I can and can not plug into this thing? Thx.

 

[Chu Gai]

i can't even find that on Liebert's site as well as google. might be an older unit. give em a call.