Surge Supressor vs UPS

P

Pascal.Pincosy

Freshman
Jan 11, 2011
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Oakland, CA
www.knowaudio.com
I'm working on upgrading some of my processing racks, and I'm curious about peoples thoughts about using a true sine-wave UPS instead of a high-quality surge suppressor. Having already been a victim of a loose neutral wire, this is something I take very seriously. Outside of the weight factor, is there any good reason I shouldn't use something like this in my racks:

Tripp Lite SmartPro .75kVA Line Interactive Sine Wave UPS, SNMPWEBCARD option, 1U Rackmount, USB, Serial, EPO, 120V (SMART750RM1U)
 
Re: Surge Supressor vs UPS

I wouldn't bother with a UPS on any items that have a fast (less than 5 to 10 seconds) recovery time upon power loss. A nice voltage regulator will absolutely protect you from out-of-range voltages, while also boosting sagging voltages due to long AC cable runs.
 
Re: Surge Supressor vs UPS

Pascal.....

That looks really good. I had my trusty Furman Line Regulator crap out on me after about 12 years, having saved my gear numerous times. For the cost of sending it in for repair I can just buy the Tripplite and add the UPS capability. Thanks for the link.

DR
 
Re: Surge Supressor vs UPS

Pascal.Pincosy said:
I'm working on upgrading some of my processing racks, and I'm curious about peoples thoughts about using a true sine-wave UPS instead of a high-quality surge suppressor. Having already been a victim of a loose neutral wire, this is something I take very seriously. Outside of the weight factor, is there any good reason I shouldn't use something like this in my racks:

Tripp Lite SmartPro .75kVA Line Interactive Sine Wave UPS, SNMPWEBCARD option, 1U Rackmount, USB, Serial, EPO, 120V (SMART750RM1U)
Click to expand...
That's likely fine. There are a couple things to watch out for with units like this. First of all - how loud is the fan noise. Second, sometimes units like this switch to battery every time they decide to change buck/boost taps (no first hand experience on this model but some APC units do this), so if you're on really soggy power, you may find that the battery is dead due to constant switching to battery on kick hits. Last, it would be worth a deep dive in the manual to figure out if the unit has a storage mode. Some units may stay partially energized even with the switch off, and so may wear out the battery in between gigs.

Assuming that none of these issues are show stoppers for this unit, it would likely be fine.
 
Re: Surge Supressor vs UPS

Pascal.Pincosy said:
I'm working on upgrading some of my processing racks, and I'm curious about peoples thoughts about using a true sine-wave UPS instead of a high-quality surge suppressor. Having already been a victim of a loose neutral wire, this is something I take very seriously. Outside of the weight factor, is there any good reason I shouldn't use something like this in my racks:

Tripp Lite SmartPro .75kVA Line Interactive Sine Wave UPS, SNMPWEBCARD option, 1U Rackmount, USB, Serial, EPO, 120V (SMART750RM1U)
Click to expand...

it is important to note that a surge suppressor won't save you from the open neutral problem. surge suppressors don't kick in until way past 220V typically. for that sort of protection you need a voltage regulator or a UPS.

Jason
 
Re: Surge Supressor vs UPS

I run a SurgeX and then the Tripp Lite SmartPro for FOH. The fan is very quiet. It will sit un-powered for a couple of months and only takes a short while to come back up to voltage and it still works in the mean time. I couldn't tell you about switching to battery power on kick hits because at 600 watts, it doesn't have enough power for any amps I own anyway. It's only for the console, computer, wireless receivers and a few other accessories.

TJ Cornish said:
That's likely fine. There are a couple things to watch out for with units like this. First of all - how loud is the fan noise. Second, sometimes units like this switch to battery every time they decide to change buck/boost taps (no first hand experience on this model but some APC units do this), so if you're on really soggy power, you may find that the battery is dead due to constant switching to battery on kick hits. Last, it would be worth a deep dive in the manual to figure out if the unit has a storage mode. Some units may stay partially energized even with the switch off, and so may wear out the battery in between gigs.

Assuming that none of these issues are show stoppers for this unit, it would likely be fine.
Click to expand...
 
Re: Surge Supressor vs UPS

Robert Patch said:
I run a SurgeX and then the Tripp Lite SmartPro for FOH. The fan is very quiet. It will sit un-powered for a couple of months and only takes a short while to come back up to voltage and it still works in the mean time. I couldn't tell you about switching to battery power on kick hits because at 600 watts, it doesn't have enough power for any amps I own anyway. It's only for the console, computer, wireless receivers and a few other accessories.
Click to expand...
I wasn't assuming that you'd put an amp on the UPS - that would be a bad idea. That being said, in environments with soggy power, sudden power draw from amplifiers even on different circuits could potentially brown out power at FOH, hence the concern.
 
Re: Surge Supressor vs UPS

You got me wondering how the UPS actually responds to fluctuating voltage. I dug out my variac and calibrated it using a Fluke 87 voltmeter. My line voltage is 123 Vac so I started there and it passes 123 Vac through the UPS. 120 V = 120 V, 115 V = 115 V, 110 V = 110 V, 107.5 V = 107.5 V, 105 V = 105 V, 102.5 v = 116 V. Ah ha, here was the threshold for the battery to kick in. This was repeatable. 100 V = 113.5 V, 97.5 V = 110.5 V, 95 V = 108 V, 92.5 V = 105 V, 90 V = 102 V, 87.5 V = 99.5 V. Then I turned the variac off and it jumped to 119 V. Turned it back on and 87.5 V = 99.5 V. Then I turned the variac up all the way. 141.8 V = 125.4 V. Accuray looked to be no worse than about +/- .5 V.

Then I reset the variac to 123 V and started switching it on and off. The interesting thing is that I switch it off and the voltage goes to 119 V and turn it on again and after a couple of seconds it reverts to line voltage, but if I turn it off again, it shuts the UPS down. I did not experiment with how much time would have to elapse for this not to happen. I was switching it off for a few seconds and switching it back on for a few seconds. The indication is that there might be a problem if the power was going off and on again a couple of times in quick succession.

TJ Cornish said:
I wasn't assuming that you'd put an amp on the UPS - that would be a bad idea. That being said, in environments with soggy power, sudden power draw from amplifiers even on different circuits could potentially brown out power at FOH, hence the concern.
Click to expand...
 
Re: Surge Supressor vs UPS

Robert Patch said:
You got me wondering how the UPS actually responds to fluctuating voltage. I dug out my variac and calibrated it using a Fluke 87 voltmeter. My line voltage is 123 Vac so I started there and it passes 123 Vac through the UPS. 120 V = 120 V, 115 V = 115 V, 110 V = 110 V, 107.5 V = 107.5 V, 105 V = 105 V, 102.5 v = 116 V. Ah ha, here was the threshold for the battery to kick in. This was repeatable. 100 V = 113.5 V, 97.5 V = 110.5 V, 95 V = 108 V, 92.5 V = 105 V, 90 V = 102 V, 87.5 V = 99.5 V. Then I turned the variac off and it jumped to 119 V. Turned it back on and 87.5 V = 99.5 V. Then I turned the variac up all the way. 141.8 V = 125.4 V. Accuray looked to be no worse than about +/- .5 V.
Click to expand...

LOL. I did the very same test last night http://soundforums.net/junior-varsity/5508-hey-digital-console-users-dont-forget-your-ups-3.html
with the same voltmeter even!

Jason
 
Re: Surge Supressor vs UPS

It would be interesting to monitor the response of the UPS with the power supply, not the UPS, under a difficult and fluctuating load closer to a real life bad power situation like TJ was talking about. An IT8000 on a 15 amp circuit driving a subwoofer, or something like that.
 
Re: Surge Supressor vs UPS

Surely it makes more sense to have an off-line UPS for your backup needs? This way you are always isolated from the line? An Online UPS seems to make little sense to me. Certainly at the higher end of the market, I have UPSes fail a lot more often than mains supplies...
 
Re: Surge Supressor vs UPS

Chris Johnson said:
Surely it makes more sense to have an off-line UPS for your backup needs? This way you are always isolated from the line? An Online UPS seems to make little sense to me. Certainly at the higher end of the market, I have UPSes fail a lot more often than mains supplies...
Click to expand...

Maybe I misunderstand but I thought the "On-Line" models were the ones with full time inverter feed of the load and the input line charging the battery? I had not heard the term "Off-Line" used before.
 
Re: Surge Supressor vs UPS

Chris Johnson said:
Surely it makes more sense to have an off-line UPS for your backup needs? This way you are always isolated from the line? An Online UPS seems to make little sense to me. Certainly at the higher end of the market, I have UPSes fail a lot more often than mains supplies...
Click to expand...
The standard name for devices where the load runs off the inverter all the time is Double Conversion. Power goes in AC -> DC to charge the batteries, DC -> AC from the batteries (and the charging circuit) to the load. In this method, there is no transfer switch - the load is always powered by the inverter from the DC subsystem.

This is surely the safest UPS, though they are less efficient than "line-interactive" units with buck-boost transformers, and always cost a lot more. You may also have difficulty finding a small double-conversion UPS; there are lots of choices from a couple KVA on up. Fewer for little guys.
 
Re: Surge Supressor vs UPS

Jason Lavoie said:
it is important to note that a surge suppressor won't save you from the open neutral problem. surge suppressors don't kick in until way past 220V typically. for that sort of protection you need a voltage regulator or a UPS.
Click to expand...
I have a whole pile of working expensive gear and some blown Furman and Trip-Lite surge suppressors that would disagree with you.
 
Re: Surge Supressor vs UPS

TJ Cornish said:
The standard name for devices where the load runs off the inverter all the time is Double Conversion. Power goes in AC -> DC to charge the batteries, DC -> AC from the batteries (and the charging circuit) to the load. In this method, there is no transfer switch - the load is always powered by the inverter from the DC subsystem.

This is surely the safest UPS, though they are less efficient than "line-interactive" units with buck-boost transformers, and always cost a lot more. You may also have difficulty finding a small double-conversion UPS; there are lots of choices from a couple KVA on up. Fewer for little guys.
Click to expand...
Double conversion UPS units are also commonly referred to as "online" and rack mount, online/double conversions units rated from 1000VA and up are fairly common (APC, CyberPower, Liebert, SurgeX, TrippLite, etc.) with some units available as small as 500VA.

It should be noted that some rack mount UPS units are quite deep and may not fit in shallower racks.
 
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