UPS connected downstream from surge strip? Surge strip downstream from UPS?

VirtualLarry

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Aug 25, 2001
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I remember reading, that one of these two was "bad". Something to do with the surge strip's shunting to ground using the MOVs during an overload, causing the UPS to trip, or something?


Right now, I just deployed an APC 1500VA UPS, and I needed more battery-backed outlets (4 AC cords, 3 wall-warts), so I have a 12-outlet Belkin surge protector plugged into the primary UPS battery-backup outlet.

Is this OK? It won't cause any "issues" (or heaven forbid, fires)?\
 

TennesseeTony

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Aug 2, 2003
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UPS downstream from surge shouldn't be a problem. You can find "whole house" surge devices in the electrical panels of many updated dwellings.

Don't know about the other way 'round though.
  • I could ramble on about how the UPS should have some surge protection built-in, making the scenario of the downstream surge strip ever going into protection mode unlikely, but it's just conjecture.
  • I have heard/read that plugging in/turning on items create surges too, not just lightning strikes.

One thing I can certainly attest to however, is that you can not get free power by plugging a UPS into itself. :blush:
 
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XavierMace

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Yes, your scenario is considered bad (and against fire code) as you're plugging a surge protector into a surge protector.

Plugging a surge suppressor into another surge suppressor may cause the one closer to the source outlet to get a bit cooked when a small surge comes down the wire. Normally, a small surge is too smal to be noticed by the circuit breaker. When the second surge suppressor clamps the surge, in addition to the first, that might be enough to trip the breaker, resulting in an outage that wouldn't otherwise have happened. Additionally, this is against the fire code in most locations.

Plugging a surge suppressor into a UPS compounds the problem. First, you have the same problem as with daisy-chained surge suppressors (except for the fire code issue). Additionally, due to the way a UPS works (the switching to create the output voltage), it's possible (maybe even likely, depending on the UPS) that small surges will be generated on the output. If there's a surge suppressor downstream of the UPS, and it clamps these micro-surges, it could damage the electronics in the UPS.

That's a pretty good summary. What you want is a plain PDU (Power Distribution Unit) as they don't provide surge protection. For example: https://www.amazon.com/CyberPower-C..._9?ie=UTF8&qid=1518710075&sr=8-9&keywords=pdu

I'm sure you could fine a cheaper one if needed, but that gives you the idea.
 

13Gigatons

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Every store sells a cheap power tap without surge suppression. They are pretty cheap.
 
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VirtualLarry

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Interesting, thanks people. Looks like I need an "outlet multiplier", and not a "surge" strip. Mostly, just for the wall-warts, mostly. Got two PCs, a monitor, and a network switch (wall-wart), and a bunch of NAS units (mostly wall-warts).

Edit: Would this be suitable?

https://www.ebay.com/itm/Rosewill-R...ximum-Power-/291286867691?hash=item43d20cdeeb

It mentions having a 15A breaker, under "Surge Supression", doesn't say anything about MOVs, or EMI/RFI filtering.

Feel free to suggest some simply Power Squid-type outlet-multiplier devices, that handle 4-5 wall-warts.
 

Red Squirrel

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I've done it that way many times and never had an issue. Right now I'm setup a little differently though, I made a large power bar with 8 outlets per side and two power cords, one power cord is plugged into the UPS battery side and the other is plugged into the surge side and the UPS is plugged into the wall. So between those outlets and the ones on the back of the UPS it's enough for everything. Everything is rated for 15 amps in my setup. I try to avoid using anything in a permanent setup that is rated lower than that as far as power bars, extension cords etc.
 

13Gigatons

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BEST ANSWER: Buy another UPS and plug it directly into the wall. It will provide you with extra outlets and increase your run time.
 

13Gigatons

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http://www.apc.com/us/en/faqs/FA158852/

Plugging a surge protector into your UPS:
The noise filtration circuitry in a Surge Protector can effectively "mask" some of the load from the UPS, causing the UPS to report a lower percentage of attached load than there actually is. This can cause a user to inadvertently overload their UPS. When the UPS switches to battery, it may be unable to support the equipment attached, causing a dropped load.

Surge protectors filter the power for surges and offer EMI/RFI filtering but do not efficiently distribute the power, meaning that some equipment may be deprived of the necessary amperage it requires to run properly causing your attached equipment (computer, monitor, etc) to shutdown or reboot. If you need to supply additional receptacles on the output of your UPS, we recommend using Power Distribution Units (PDU's). PDUs evenly distribute the amperage among the outlets, while the UPS will filter the power and provide surge protection. PDUs use and distribute the available amperage more efficiently, allowing your equipment to receive the best available power to maintain operation.


Plugging your UPS into a surge protector:
In order for your UPS to get the best power available, you should plug your UPS directly into the wall receptacle. Plugging your UPS into a surge protector may cause the UPS to go to battery often when it normally should remain online. This is because other, more powerful equipment may draw necessary voltage away from the UPS which it requires to remain online. In addition, it may compromise the ground connection which the UPS needs in order to provide adequate surge protection. All APC Back-UPS and Smart-UPS products provide proper surge suppression for power lines without the need of additional protection.
 

VirtualLarry

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That doesn't sound nearly as "scary" as what @XavierMace posted. I think that I'll keep my current setup then, if APC doesn't warn against fire or code violations.
 

dlerious

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Mar 4, 2004
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Interesting, thanks people. Looks like I need an "outlet multiplier", and not a "surge" strip. Mostly, just for the wall-warts, mostly. Got two PCs, a monitor, and a network switch (wall-wart), and a bunch of NAS units (mostly wall-warts).

Edit: Would this be suitable?

https://www.ebay.com/itm/Rosewill-R...ximum-Power-/291286867691?hash=item43d20cdeeb

It mentions having a 15A breaker, under "Surge Supression", doesn't say anything about MOVs, or EMI/RFI filtering.

Feel free to suggest some simply Power Squid-type outlet-multiplier devices, that handle 4-5 wall-warts.
I bought something like this years ago for my power bricks https://www.amazon.com/gp/product/B...64-813f-53f0-bf8d-4b7a4f830f14&pf_rd_i=495312
 

XavierMace

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That doesn't sound nearly as "scary" as what @XavierMace posted. I think that I'll keep my current setup then, if APC doesn't warn against fire or code violations.

You asked if what you were doing is bad. The answer is yes. Using Red's logic of "I've never had an issue" is the same reason some people don't wear seat belts. Have I daisy chained power strips in a pinch? Yes. But I wouldn't do that all the time, and I certainly wouldn't plan on doing it. Especially since you live in an apartment. If you got inspected, I don't think that would go over well.
 

bigboxes

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The rule is not to plug a UPS into anything but a dedicated outlet. No surge strip first.
 

VirtualLarry

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The rule is not to plug a UPS into anything but a dedicated outlet. No surge strip first.
I know that much, at least, I think I do, but what about putting a surge protector into a UPS, to get more outlets for power bricks?
 

Red Squirrel

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I'm curious what is the science behind not connecting a UPS into a surge bar or vise versa? I heard about this before but always figured it was just some kind of wive's tale or something.
 

Pick2

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Spike ( voltage ) , surge ( current ) and combo filters use a combination of capacitance and inductance to smooth the 50/60 cycle AC.
UPSs closely monitor both it's input / output voltage and current to detect when to switch over to standby or to cut output if it's over current.
The Caps and inductors can play havic with monitoring what's actually going on.
 
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