Choosing a UPS

[monokakata]

A line-interactive UPS will run the output from the AC input (after any filtering and voltage regulation), so I would expect that the output is close to a regular sine wave most of the time. Only when on battery would the inverter be running to supply power, and it generates the stepped-sine.

That's the theory as I understand it. I haven't tried to fire up the ancient Eico 460 to verify that, though.

Eico! Oh, my. Showing our ages, are we?

 

[Larry-K]

Trying to decide which UPS to get...

The following would be connected to the UPS:

• 2008 Mac Pro (3 hard drives @ 7200RPM, 1 Samsung 850 EVO SSD, and an ATI Radeon HD 5770 graphics card)
• 20" Apple Cinema Display aluminum
  
• external hard drive
• Netgear 5 port network switch
• Some smaller peripherals (USB/FireWire hub, card reader, etc.)

I believe the Mac Pros have a 980 watt power supply and the 20" Apple Cinema Display is 65 watts...?

I was looking at these two UPSs from APC and CyberPower

• APC Power-Saving Back-UPS Pro 1500
  
• CyberPower CP1500PFCLCD PFC Sinewave UPS System

Is a pure sine wave necessary for a 2008 Mac Pro? I've always used APC personally, but the CyberPower model does intrigue me especially since it has a pure sine wave at about $40 more, while the APC model does not. But the APC model is compatible an external battery pack which effectively increases the battery capacity and thus the run time.

Any opinions?

Thank you.

The "Pure Sinewave" marketing gimmick wasn't around when the 2008 came out.

I have cyberpowers on all my MacPros, including a 2008, they got no problems.

 

[monokakata]

The "Pure Sinewave" marketing gimmick wasn't around when the 2008 came out.

I don't think it's a marketing gimmick.

Over the years, I've had equipment that couldn't handle what came out of early UPSs, like square waves and even stepped sine waves. The power supplies would buzz, for example.

Also, looking at it from the input side, I've had UPSs that couldn't handle input from generators. I used to work with a guy who ran our joint field operation on a 5 kw Honda generator. The APCs I was using then would switch to battery power immediately. The Clary, an Exide, and a Best unit (all line-isolated units) didn't care what they saw on the AC side. Then I got my own Honda inverter generator and that one put out a waveform that all the UPSs liked just fine, and still do (I have a couple of APCs around the house).

Waveform isn't a marketing gimmick.

 

[Larry-K]

I don't think it's a marketing gimmick.

Over the years, I've had equipment that couldn't handle what came out of early UPSs, like square waves and even stepped sine waves. The power supplies would buzz, for example.

Also, looking at it from the input side, I've had UPSs that couldn't handle input from generators. I used to work with a guy who ran our joint field operation on a 5 kw Honda generator. The APCs I was using then would switch to battery power immediately. The Clary, an Exide, and a Best unit (all line-isolated units) didn't care what they saw on the AC side. Then I got my own Honda inverter generator and that one put out a waveform that all the UPSs liked just fine, and still do (I have a couple of APCs around the house).

Waveform isn't a marketing gimmick.

If your UPS is putting out a square wave, it's apiece of junk.

Put an oscilloscope on what comes out of the wall, it's sad, but it's good enough to run a computer, all you're doing is translating it down 12VDC anyway. Your power supply doesn't sit around admiring the curves.

 

[monokakata]

As I said,

"Over the years, I've had equipment that couldn't handle what came out of early UPSs, like square waves and even stepped sine waves. The power supplies would buzz, for example."

Early. As in long ago. I'm talking late 80s, early 90s. I don't have any of those any more.

And I'm pretty sure a power supply designer would disagree with what you say. I'm not a power supply designer, and I'm guessing that you aren't either, so we'd best let this one drop.

 

[Larry-K]

As I said,

"Over the years, I've had equipment that couldn't handle what came out of early UPSs, like square waves and even stepped sine waves. The power supplies would buzz, for example."

Early. As in long ago. I'm talking late 80s, early 90s. I don't have any of those any more.

And I'm pretty sure a power supply designer would disagree with what you say. I'm not a power supply designer, and I'm guessing that you aren't either, so we'd best let this one drop.

Since I actually worked with a power supply designer on some of the first solid-state inverters for military aircraft in the early 70s, I don't think one would.

 

[tech4all]

A line-interactive UPS will run the output from the AC input (after any filtering and voltage regulation), so I would expect that the output is close to a regular sine wave most of the time. Only when on battery would the inverter be running to supply power, and it generates the stepped-sine.

That's the theory as I understand it. I haven't tried to fire up the ancient Eico 460 to verify that, though.

Thank you for the input and explanation, @kschendel!

The "Pure Sinewave" marketing gimmick wasn't around when the 2008 came out.

I have cyberpowers on all my MacPros, including a 2008, they got no problems.

I don't think it's a marketing gimmick.

Over the years, I've had equipment that couldn't handle what came out of early UPSs, like square waves and even stepped sine waves. The power supplies would buzz, for example.

Also, looking at it from the input side, I've had UPSs that couldn't handle input from generators. I used to work with a guy who ran our joint field operation on a 5 kw Honda generator. The APCs I was using then would switch to battery power immediately. The Clary, an Exide, and a Best unit (all line-isolated units) didn't care what they saw on the AC side. Then I got my own Honda inverter generator and that one put out a waveform that all the UPSs liked just fine, and still do (I have a couple of APCs around the house).

Waveform isn't a marketing gimmick.

As I said,

"Over the years, I've had equipment that couldn't handle what came out of early UPSs, like square waves and even stepped sine waves. The power supplies would buzz, for example."

Early. As in long ago. I'm talking late 80s, early 90s. I don't have any of those any more.

And I'm pretty sure a power supply designer would disagree with what you say. I'm not a power supply designer, and I'm guessing that you aren't either, so we'd best let this one drop.

Since I actually worked with a power supply designer on some of the first solid-state inverters for military aircraft in the early 70s, I don't think one would.

Thank you both, @Larry-K and @monokakata, for sharing your views on pure sine wave UPSs. Interesting points to consider. I suppose it couldn't hurt to have a pure sine wave UPS, but that could be wasted money (unless you want other features besides a pure since wave of a higher-end UPS) if a pure sine wave is just a gimmick. I'll have to do more research on that.

 

[monokakata]

Thank you for the input and explanation, @kschendel!

Thank you both, @Larry-K and @monokakata, for sharing your views on pure sine wave UPSs. Interesting points to consider. I suppose it couldn't hurt to have a pure sine wave UPS, but that could be wasted money (unless you want other features besides a pure since wave of a higher-end UPS) if a pure sine wave is just a gimmick. I'll have to do more research on that.

Larry-K and I agree on at least one thing, which is that the Cyperpower units are good units. I've got 2, as I said, and he seems to have at least one. And they do have sine wave output.

So you might look in that direction.

 

[tech4all]

Larry-K and I agree on at least one thing, which is that the Cyperpower units are good units. I've got 2, as I said, and he seems to have at least one. And they do have sine wave output.

So you might look in that direction.

Yea I'm thinking of doing that. The CyberPower does get good reviews various sites. Hopefully I'll get it soon...makes me a little nervous not having a functioning UPS.

 

[msh]

I don't think it's a marketing gimmick.

Over the years, I've had equipment that couldn't handle what came out of early UPSs, like square waves and even stepped sine waves. The power supplies would buzz, for example.

Also, looking at it from the input side, I've had UPSs that couldn't handle input from generators. I used to work with a guy who ran our joint field operation on a 5 kw Honda generator. The APCs I was using then would switch to battery power immediately. The Clary, an Exide, and a Best unit (all line-isolated units) didn't care what they saw on the AC side. Then I got my own Honda inverter generator and that one put out a waveform that all the UPSs liked just fine, and still do (I have a couple of APCs around the house).

Waveform isn't a marketing gimmick.

I encountered this when I first got my '09 Mac Pro. Buzzed like hell on a APS simulated sine wave UPS on battery power. As soon as I switched to the APS Smart UPS 1500 real sine wave model problem was solved and still running well today. Best get the pure sine wave UPS'.

 

[PinkyMacGodess]

One thing that does happen, and it may be an issue with the external drive enclosure since I've seen reports of this in the reviews of the enclosure, the drive enclosure powers down when it has to go to battery backup.



Both the UPS noted above and one I have my home theater setup plugged into do this, I believe it's a self-test of sorts.

First point: Is the enclosure just not powering back up after the power is restored? There is a gap of no power before the UPS kicks in.

Second: Mine trips occasionally during the day also. Sometime I can see a slight dimming of the lights. Sometimes when the air conditioner starts I get the 'trip'. It's trying to supplement the power to keep the output at the set level.

One other thing: I was told by APC support that I should unplug the UPS occasionally, maybe once a month , and let it run down for a few minutes as it helps 'recondition' the batteries, otherwise they just keep trickle charging and eventually 'cook', and swell and start leaking. The UPS's of old did have a 'self test' feature, that was software driven. I haven't seen that feature in the last few that I have installed. For what it's worth...

A few years ago, we had an APC 'go nuts' after the power fluctuated, and the batteries were apparently 'cooked'. It kept switching to battery power and back again, several times a second from what I could tell, and fried the power supply in our firewall. I used to consider UPS's as an 'install and forget' item. Keeping an eye on them is a good idea. I, after actually catching it doing the 'flip out thing', was able to disconnect it and save the new power supply, and replace the UPS.

 

[hallux]

First point: Is the enclosure just not powering back up after the power is restored? There is a gap of no power before the UPS kicks in.

The Mac Mini never power cycles. Only the enclosure shuts off when the power goes out and the Mini reports that the disks were not ejected properly.

 

[PinkyMacGodess]

The Mac Mini never power cycles. Only the enclosure shuts off when the power goes out and the Mini reports that the disks were not ejected properly.

That's interesting. It must be sensing the power issues when the UPS kicks on. I had that happen with a client. They rarely had the power go down, so they just ignored it. I can't remember what the device was as it was a long time ago. I just remember researching how to provide uninterrupted power in the case of a power outage and the UPS switch-over is sensed. You can do it, but it's expensive, or at that point it was.

I'd investigate the power-supply of the enclosure. There might be a spec issue...