Question UPS surge protection

[bjlockie]

If the surge protection part of a UPS gets used up, will the battery part still work?
Then there isn't any indication of if the surge part is still working.

 

[mindless1]

Generally yes, the surge protection uses discrete components to shunt the surge voltage above the desired threshold, across live/neutral or to ground, and when they get used up they just fail to open circuit, sometimes spectacularly so with a burst component, or if they short but don't blow, then it would trip the breaker or a fuse.

If the breaker or fuse trips, then the battery part may stop working if it's a shared/main breaker at the AC inlet to the UPS. By not working I mean it is usually just the mains AC input that gets disconnected and the battery having a charge, continues to power the AC inverter so that still works

"Usually" it is only the surge protection that becomes less effective (could have more than one shunt method in parallel and only one of those failing first) or completely ineffective, and the battery charging, and AC inverter continue to function, unless of course the surge damaged it too. Surge protection is about mitigation but is not perfect.

I'm fairly certain that some UPS do indicate if the surge protection circuit has failed. Look in the owner's manual. You can also open the UPS and examine it. A failed surge suppression component tends to look burnt up or missing/exploded.

If you have enough surges to worry about this, then I suggest a separate surge protection before the UPS, or a whole-premises surge protector. Plus this will let you decide ow much to spend on what quality and capacity of surge protector. A basic UPS tends not to have the greatest urge protection, and so it may be as economical to buy the purpose specific surge protection level you need rather than stepping up to a commercial grade UPS with better surge protection. Depends on the value and uptime requirements of your equipment being protected.

 

[bigboxes]

Generally yes, the surge protection uses discrete components to shunt the surge voltage above the desired threshold, across live/neutral or to ground, and when they get used up they just fail to open circuit, sometimes spectacularly so with a burst component, or if they short but don't blow, then it would trip the breaker or a fuse.

If the breaker or fuse trips, then the battery part may stop working if it's a shared/main breaker at the AC inlet to the UPS. By not working I mean it is usually just the mains AC input that gets disconnected and the battery having a charge, continues to power the AC inverter so that still works

"Usually" it is only the surge protection that becomes less effective (could have more than one shunt method in parallel and only one of those failing first) or completely ineffective, and the battery charging, and AC inverter continue to function, unless of course the surge damaged it too. Surge protection is about mitigation but is not perfect.

I'm fairly certain that some UPS do indicate if the surge protection circuit has failed. Look in the owner's manual. You can also open the UPS and examine it. A failed surge suppression component tends to look burnt up or missing/exploded.

If you have enough surges to worry about this, then I suggest a separate surge protection before the UPS, or a whole-premises surge protector. Plus this will let you decide ow much to spend on what quality and capacity of surge protector. A basic UPS tends not to have the greatest urge protection, and so it may be as economical to buy the purpose specific surge protection level you need rather than stepping up to a commercial grade UPS with better surge protection. Depends on the value and uptime requirements of your equipment being protected.

You don't want anything between the UPS and the outlet. No power strips/surge protectors or another UPS. Just UPS straight to the outlet.

 

[mindless1]

^ Why? Electrically that does not make sense. I'd like to see some professional rebuttal/evidence?

I suppose someone could suggest this causes higher impedance to the earth ground, but it doesn't necessarily introduce much more, and there's already also that of the outlet connection and however much premises wiring to get to that outlet, which is one of the reasons a whole site surge protector is best, and yet then you still have another surge protector in series before the UPS.

I mean a surge protection circuit, obviously there is little point in daisy chaining UPS, one to feed another for the primary UPS purpose.

Edit below:
------------------------------------------------------------------------------------------

I am investigating this. I saw it mentioned by Cyberpower but not rationale why. I suspect they are just concerned a customer will be drawing too much power from the wall outlet because the surge "protector" is in an outlet strip that more is being plugged into, so the outlet is strained or the UPS sees a voltage drop and kicks in more often.

Can I hook up a surge strip to the UPS unit?

Surge strips cannot be installed before OR after the UPS unit. Doing so will void the UPS' warranty. If you require additional units, please upgrade your UPS to a unit that has more outlets.

www.cyberpowersystems.com

I saw the following but it only cites reasons not to plug the surge protector, multi-outlet strip into the UPS, not the other way around except as mentioned above, if something drawing a lot of power is plugged into the surge strip besides the UPS, not primarily using it for surge protection.

Should You Plug a UPS Into a Surge Protector?

Even the people making these devices seem to disagree on the topic.

www.howtogeek.com

Then I saw the Anandtech Forum topic which suggests the same.

Is it safe to connect an multi-outlet surge protector to a UPS?

I bought a new UPS recently and I notice that there aren't enough outlets in the back to connect my gadgets and computers. My plan is to connect the UPS directly to the wall. Then attach a multi-outlet UPS like the APC or Belkin 12-outlet surge protector to the back of the UPS. Is this...

forums.anandtech.com

Then I saw this, which does not even make sense except the idea that if the UPS, due to a surge strip or an extension cord, is far enough away from the outlet that it causes a voltage droop that causes the UPS to rely on battery power. It states a power strip can increase the current into the UPS but this is only if an online UPS and then only if a long run that drops voltage, and even then it doesn't necessarily mean it draws too much.

Should You Plug Your UPS into a Power Strip? - APC UPS Blog - ExcessUPS.com

excessups.com

Essentially it seems to boil down to "we can't test whatever you're doing so don't". They are stating things that would apply whether it's a surge protector or just an outlet strip or just a long or too high a gauge extension cord for the load.

A second surge protection circuit in parallel does not by itself introduce additional risks, on the contrary it has additional benefits and many better surge protectors do incorporate more than one surge suppression path/circuit within them, not just throw 3 MOVs in it and call it a day.

 

[Mantrid-Drone]

I don''t know about an UPS but for years I've used individual surge protectors on surge protected 6 and 8 gang mains extension leads.

I can see no reason why you should not protect the UPS (which themselves are expensive bits of kit) with a surge protector of some sort. Why should it harm the UPS? It is basically just a one time fuse or a mechanical/electronic trip of some sort no different from that used in a domestic building's consumer unit or fuse box.

 

[Tech Junky]

If surge is the worry why not just block it at the box?

The Best Whole-House Surge Protectors of 2023

Extreme weather and voltage fluctuation are common causes of power outages. View picks for the best whole house surge protector to maintain power here.

www.bobvila.com

There are a good selection of them and any additional surge protections downstream are additional peace of mind.

 

[aigomorla]

^ Why? Electrically that does not make sense. I'd like to see some professional rebuttal/evidence?

Well the theory was the surge protector did not have enough capacity to handle a UPS.
For example, some of my UPS's are very beefy, require a NEMA 20. They won't work in normal surge protectors until you bring out PDU, which is like an enterprise edition surge protector with NEMA 20 ports.

And a UPS is in a sense a Surge protector itself, so it follows all the rules or trying to not run a surge protector on another surge protector, especially if the one on the last chain has the most capacity out of all of them, as they can trip primary surge protector.

 

[mindless1]

^ Okay sure, anything upstream has to have an equal or higher capacity whether a surge protector, multi-outlet strip, or just an extension cord.

 

[aigomorla]

^ Okay sure, anything upstream has to have an equal or higher capacity whether a surge protector, multi-outlet strip, or just an extension cord.

But you run into a problem when its NEMA-15A.
Lets say you have a NEMA 15 UPS... and your surge is 15A.
Well, theoretically with loss, you wont be able to run that UPS @ 15A transient, because your going to get loss down the rails on a Surge protector.

So you will trip it unless you got a pretty sad UPS with very low power delivery.
Which i guess most are, as most consumer UPS top at about 900W.

 

[mindless1]

^ I don't follow what you're stating. You wouldn't pick a 15A UPS or surge device for a 15A load and the surge itself is usually low current, high voltage. If it trips, that's what it was supposed to do.

 

[aigomorla]

^ I don't follow what you're stating. You wouldn't pick a 15A UPS or surge device for a 15A load and the surge itself is usually low current, high voltage. If it trips, that's what it was supposed to do.

No because you lose power down the chain...
So lets say you used 3 x 15A surges in a 3 part chain. A - B - C

Lets say:
C drew the full 15A.
B would need to draw 15A + X (X being the loss from the bus rails and heat as as were not talking about super conductors)
B would trip... as it would be too much.
A would need to draw 15A + X + X ( another big trip.)

That would mean C's true draw amperage without tripping = 15A - X - X = (15A -2X) which means your gimping C or you will trip everything above it.

This is why they say keep the UPS and surge right at the wall and source, so you can get the value of (X) as small as possible.

 

[mindless1]

^ Except that's not how you're supposed to do it. You never pick a surge strip or UPS to run at full rated load.

The losses from a decent quality protector is not that much. If you buy junk, sure, you have to derate for that even more, as you would as the socket contacts get weaker and oxidized, or cord gets frayed from moving it around over time, etc... even the wall outlet itself is susceptible to issues over time running near its rated max current.

You're still better off having the extra protection upstream as sacrificial parts instead of damaging a more expensive UPS, and then if it shuts off, it shuts off.

 

[aigomorla]

Except that's not how you're supposed to do it. You never pick a surge strip or UPS to run at full rated load.

and how many times have you done something that people told you not to do just because you could?



But i was honestly speaking hypothetical. I would never do it.
But then again, i do not put my UPS's at the socket or a surge protector, they are behind dedicated PDU's and my PDU's are NEMA 20 on NEMA 20 sockets with 12/2 wiring.

 

[mindless1]

^ Hold my beer events don't count!

I fully respect hard limits and margins imposed by electrics. They are not negotiable.

 

[aigomorla]

I fully respect hard limits and margins imposed by electrics. They are not negotiable.

Sure they are... you don't believe in free energy, and breaking the rules of thermodynamics?
*puts on tin foil hat*