Electricity surges: best practices?

Hi all,
In the hot summer we are having up here in Ontario (Canada), we’ve been having lots of electricity surges in the early morning hours. I have a habit (which may change) of leaving my mac studio on. This morning I awoke to a rather concerning situation: all external drives not mounting and usb-c dock seemingly fried. I seem to have saved everything (i.e the drives were not in fact fried, although the OWC dock is not responsive). The critical stuff is backed up on the cloud, but I just wondered if anyone had best practices or particular products for safety that might be worth looking into for someone who has been far too cavalier.

Use a robust surge protector system. Most have in-built battery back-ups. Some also provide warranty or insurance coverages for damages. Many vendors exist.


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I’ve got all of my valuable electronics plugged into surge protectors. With the caveat that I don’t know if they would actually protect in all cases, they’re cheap and small enough to add everywhere. Warning: I think they eventually stop protecting based on how many surges they’ve experienced, so you might want to be prepared for this to be a consumable purchase.

I’ve got these ones that you just put right on the wall outlet.


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Yes, I had the mac plugged into a cheap protector. I wonder if that’s my problem here, that it had gone through too many.

Well here in So CAL - I just had a 10 minute power outage a little while ago.

We get a lot of lightning and occasional monster storms that cause power outages. I’ve had good luck with Tripp-Lite isobar surge protectors (no backup power supply).

Years ago an electrician doing some work on the house suggested a surge protector at the electrical service box in the basement. I agreed and paid to have it installed. Its little green status light is still on although I don’t know enough to vouch for its utility. Other than not having lost any gear to lightning and surges.

I put these between the wall and my electronics.


Instead of just an surge protection, I would take it a step further, and have a look onto an UPS.


Thank you - these are all really helpful suggestions.

Good surge protectors will have LEDs on them indicating it they are still providing protection. Once the LEDs go out, time for a new one.

A whole house surge protector. We had one installed earlier this year. Relatively inexpensive and easy to install. (Great minds … :slight_smile: )

In addition to surge protection these are good for power outages. I’ve got them on my Mac and peripherals, and the cable modem router. For short outages there is no interruption. For longer ones they provide enough time to power down the system gracefully. They can also smooth out the power input → output.

However, even with all this …

Last summer we had two direct lightning strikes, two weeks apart, on the power pole at the end of our driveway. Two cable modem/routers, one 2018 Mac mini, a OWC hard drive enclosure (but not the drives inside), two external drives were fried (all on my system, my wife’s iMac and drives came through unscathed). Time Machine and Back Blaze were key to getting things back up [pun!] and running (so have a good backup strategy!). It was after this that we had the whole house surge protecter installed.

Other surge vectors include phone landlines, ethernet cables, and cable lines (any wire into the house). You’ll need to decide how paranoid you want to get with securing against those threats.

Finally, if you think there will be an issue, take steps to ward it off. In your case shutting the Mac and peripherals down at night on those hot summer days may be the prudent course.

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I have 4 UPS units in the house for various computer and electronic devices. In addition there are a number of standalone surge suppressors for minor stuff. I also have whole house surge suppressors. Finally I have a backup generator with automatic start and transfer switch. I barely notice power outages.


Actually, to have a real kind of a “protection” against lighting strikes, eighter direct strikes, and nearby (which could mean some kilometres distance, depending on the circumstances) you have to go with a 3 part Protection System.

  1. A Lightning conductor
  2. A inner protection on all systems with wires or other connections running into the house (Electric, Internet, Telephone, Cable-TV, Water, Wastewater, District heating and so on)
  3. A additional Surge Protection (or UPS) for every device plugged into the building and its lines on some kind of a way (Beside the WIFI-Cable wich is surprisingly self protective on some weird reason).

A Protection like that was estimated for the House I live in was estimated around 45.000€.
So, I have the most important devices behind a UPS, which most probably just “melted” in case of a nearby strike, and live with the risk, and the “chance” to spent the money rather on a new device every 10-20 years, instead of spending it into a protection, that still depends on the strength (and fails if the Energy is too high) of the actual lightning strike that is happening, and needs a yearly costly check (about 25% more expansive, than what I could save yearly on my Insurance) by a certified electrician, to be recognised at least with the insurance company.
So yeah, we all have to deal with the nature, and in case a strong Sunstorm hits us, all that protection is completely worthless.
BTW, due to the area around us, we can observe all thunderstorms and other heavy weather (coming with heavy lighting, and partly flooding and so on), from our house in the area around us, but they are with a rate of >95% missing our part of our small town, and hitting the areas and towns around us.

Yes, I’ve just set an automatic shutdown routine for my machine to avoid this through the summer. Good call

Fellow Ontarian reading this thread with interest. Just wanted to join with you and express that we are having power issues this summer in our area I haven’t seen since the mid-2000s. It’s been wild. Was in Burlington a couple weeks ago and saw the power was out all along the waterfront, with nary a storm in sight. I joked to my father in law, who was with me at the time, that the sun must have hit the power plant the wrong way that morning. Very odd.


This. There are multiple things to worry about with power, and surges are only one part - “brown outs” are another. Technically these are called “overvoltage” and “undervoltage”, and the typical UPS protects against both.

I had an old-school computer guy give me some sage advice once - “there’s nothing that protects against a direct lightning strike”. The most you’re going to do is mitigate damage. The advice from @MevetS is good - look at any wires that get anywhere near your computer equipment, and see if it’s possible to surge-protect them.

If I’m that concerned, I don’t shut down - I unplug. A lightning strike can damage things that aren’t turned on, as long as they’re plugged into the system. Again, watch other wires. A coaxial cable for a cable modem that has an ethernet run to your computer is a surge vector.

One last note here is UPS sizing. UPS sizes printed on the box / used in model numbers are given in VA, which is “Volt-Amps”. And despite what was taught in school, “volts x amps” is not how you calculate watts. It’s “volts x amps x power factor”.

So a UPS like this:

is a “1500”. Which leads some people to say “oh, okay, that will give me 1500 watts”. Then they plug 1500 watts of stuff into it, and when the power goes out everything on their UPS does too because the UPS can’t provide the power it needs. I’ve seen this happen.

But if you read the further description, it’ll tell you it’s 900 Watts. That’s the number you use. Also, look at projected runtimes. If you load that UPS up to 900W of devices, you might get something like 5 minutes of runtime. Put a single M1 Mac Mini on it that’s averaging something like 30 watts, and you’ll get a long, long time.

This means you want to resist the temptation to just take your existing surge protector for your computer equipment and plug that into the UPS - that’s how you get into trouble.

UPSs have two sides - “surge” and “protected”. Divvy things up so that only what needs to stay running is plugged into “protected”.

For me, the “protected” side gets my actual computers and my external drive enclosure. The “surge” side gets my monitor (unless I expect a long outage and need it to shut the computers down), any peripherals, wi-fi routers, scanners, printers, etc.

That way the incredibly limited, expensive-to-extend battery power does the most good for me. And if I needed more runtime than what my UPS provided, I’d either have 3 UPSs (one for each computer / drive enclosure), or I’d have one super-giant one with extra batteries, or I’d have something like a whole-home generator system with a transfer switch.

Hope that’s useful. :slight_smile:

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Yes. I’m just across from Burlington in Hamilton. I am often not around in summers (usually fieldwork in S.America), but COVID has me fairly local. So these power outages have been a wake-up call to get myself better protected!

Yep. And I’ve noted elsewhere, in a thread about remotely powering on a headless Mac mini, that is my habit as well. :slight_smile: But for the original poster’s use case it may not be needed if the equipment is protected by working surge protectors?

I actually have two for my computer setup and one for my modem/router set up.

And the whole house generator with transfer switch is under consideration.

Off topic but what do you do in South America?

I’m an archaeologist.

Cool. We had friends over yesterday, one of which is also an archaeologist, she works mainly in the US.

And I’ll be trekking the Inca Trail to Machu Picchu later this summer.

Stay cool and powered up.

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Surge protectors are good, but a direct lighting hit can get through a surge protector. If that’s a concern, always unplug. :slight_smile: