Surge protector

@jea48

I use the Siemens BoltShield, and the reviews are much better. The complaints seem to be from defective units that are DOA or people misunderstanding how the indicators work. Seems a lot of people received pre-owned/defective units from Amazon.

The reviews from Home Depot and Lowe's are also much better. 

Dammit, I did the Vrms to Vpk conversion wrong..... my bad!

A 120Vrms has a Vpk of ~170V. 

Doh! It's been too long.

@jea48 -

Class D amps may have a linear or a switch-mode supply in front of them. If linear, it’s just like any other amp and inrush current depends on whether the designer put an turn-on limiter on it or not. Larger amps really should have this feature.

If it’s an SMP supply though there’s almost always a smooth, low current ramp on until it stabilizes and turns on the amp portion.

PS - you can tell the difference by weight.  A linear supply is going to have a large transformer associated with it.

@ozzy I've had similar experiences with a whole house unit.   The one piece of gear I lost was a laptop (Macbook Air with amazing battery life, so sad) which was the only piece of kit in my home that was not further protected by plug in strips.

@squared80 -

For safety and reliability reasons whole house surge suppression units have a clamping voltage around 400V from neutral.  I can tell you from personal experience they don't do great with sensitive electronics. Lets talk specs though:

A 120V circuit goes up and down 60Vrms from the neutral, which has a peak of ~ 85V .

60Vrms = 60V * square_root(2) = 84Vpk

According to actual third party testing here with a 5kV surge the Furman PST-8 let an additional 40 Volts through. Lets do the math:

400Vpk - (84Vpk + 40) = 270V additional volts before clamping starts.

I quote the review here:

It turned a 5,000-volt surge into just 40 volts, thanks in part to a shutdown circuit that turns off all power when it detects a surge. The Furman PST-8 actually let less voltage through in our tests than high-end series-mode surge eliminators that can cost hundreds more.

@lanx0003

1 - There are EMI/RFI filters, and wave shaping filters. The first aren’t doing anything below 100 kHz and are in parallel, the latter aren’t doing anything below 3 kHz, which is well above the 50 or 60Hz line frequency. I really don’t understand why people think that the power pole is cleaner than the power they have at their outlet, it often is not. The last thing I want is a super conductor between my amp and the power pole, which is what seems to be the target for audiophiles. I want resistance. I want inductance. Enough at least to reduce noise transmission and ensure surge protectors have time to work.

In order of preference, Furman and Tripp Lite, but please do take a look at the Wirecutter article as the brand AND model matters. Furman without SMP/LiFT is just another power strip.

2 - Well, the type matters because it’s not always on. I use these strictly for my PC, Internet access devices and CPAP. The PS Audio units are essentially the same idea, with Class D outputs (and noise) and very short run time. 🤣 There are UPS with sine wave outputs which are still a lot cheaper than the PS Audio units, but for whatever reason, the sine wave units tend to have a higher failure rate than the stepped voltage output units.

OP:

I’m sorry to ask, but any chance you could get a plug in AC tester like this one from Kaiweets or this one from Klein? Something is very wonky.  Test your outlet and test the resulting V at the Furman as well.

Of course, if you have a multimeter and know how to use it you should, but these will test the hot, neutral and the Kaiweets will even measure the N to G voltage.

PS - Those are direct links, not associate links.

I should point out that blackouts are potential causes of surges, both when the power gets disconnected and when the power is restored.  As a child in Atlanta we lost many appliances when power came back on.

I will say that so far in my life I have NEVER experienced any type of surge activity that damaged any of my components, and once upon a time I never even used to unplug my gear during thunderstorm activity--I was happily oblivious.

@jea48

I think this may very well be location dependent. Living in SC, I randomly asked a few people who are NOT techno or audiophiles if they’ve lost equipment to power surges and everyone I asked had. One both in the Berkshires and in South Carolina.

I’ve lost gear or been present when gear went bad half a dozen times in my life. In the last 3 years alone I’ve lost a laptop (plugged in directly) and a cable modem to surges. When I moved in there was in fact a burnt out surge protector still screwed into an outlet, presumably where a TV had been. I lose power about 4x a year due to storms, plus we have about 3 power incidents per year not related to storms when the power goes out or my UPS on my computer has to intervene or my Furman shuts the power off to the stereo or both.

The differences in experience based on geographic location certainly justifies why readers may or may not wish to spend the money for the extra protection. I 100% understand that. What I don’t understand are those who only focus on direct strikes, cause that’s rarely been how I lost gear.

@12many True. OTOH, Wirecutter is literally the only time I’ve seen actual surge testing done by a third party.

Every other review I’ve seen for surge protectors is basically just reading the online specs.

If you do happen to find actual surge testing done by others, please let me know.

Yes, a panel mounted surge protector nearest the incoming power cables is best and has the lowest RL. Worth giving up 2 or 4 slots for. Next is wired, and as close to entrance of service wiring as possible.

The issue is that they are parallel devices that need to move lots of current to keep the voltage at the other breakers down.  High R or L makes them less effective.

@immatthewj You are correct. and most surges capable of damaging electronics are invisible.

For some reason some people equate a power surge only with visible near by lightning strikes which cause visible arcing and sparks inside the home. The theory goes, well, if that’s what will damage my gear then there’s nothing I can do.

I wrote more about this here:

So, I asked Pi.ai for a little help in reading, and Pi brought up 3 points worth discussing:

Type 3 Surge Protection Devices (SPDs) are typically installed at a distance of at least 10 meters (33 feet) from the main electrical panel or power distribution board for a few reasons:

1. To allow for proper voltage clamping: Installing the SPD at a certain distance from the panel allows it to effectively clamp down the overvoltage surge before it reaches the equipment being protected. This distance ensures that the SPD has enough time to react to the surge and divert it to ground safely.
2. To avoid potential damage to the electrical panel: If an SPD is installed too close to the electrical panel, there’s a risk that the surge energy diverted to ground by the SPD could damage the panel itself or the wiring connected to it.
3. To reduce the risk of interference: By keeping the SPD at a safe distance from the electrical panel, it minimizes the potential for electromagnetic interference (EMI) or other types of interference that could negatively impact the performance of nearby electrical equipment.

It’s been a really confusing read since some type 3 devices are permanently installed, and others are plug and cord.

If you use any series mode protection (Furman SMP, Brickwall or Zerosurge) these three points are moot. The low pass filter they incorporate (aka wave shaping filter) slows the super-fast rise time of a surge and reduces current flow due to the surge, and gives the surge protector enough time to disconnect if needed.

In essence the 10m requirement uses the wiring in the building as a RL low pass filter to ensure MOV’s downstream have time to react and won’t actually stress the AIR (Amp Interrupt Rating) of upstream breakers (kind of what I mentioned). However, series mode protective devices ARE RL filters (more L than R).

Other devices which are not strictly series mode like older Panamax may also include enough wave shaping to let the MOVs do their job.  It's not exactly guaranteed, but you can't really get to very low let through voltages without some sort of wave shaping/filtering in place because MOVs alone can't clamp low enough and fast enough to keep the let through voltages down.

Sounds like a cord and plug Type 3 SPD will do little, if anything, for protecting audio equipment from a high voltage transient event if the branch circuit wiring is less than 30ft long.

Well, that sure explains why Wirecutter’s testing with 5kV is useless... (not).

Based on other readings in the NEC, my understanding is that when the NEC includes minimum wiring distance as important they are considering the total amp interrupt rating. That is, if a short should occur, will it cause too much current for the upstream breakers. They are not making a statement about the effectiveness of the surge protector. They are saying you should keep it far enough away to ensure when the protector does work it won’t overload the breakers.

In the case of SMP devices, this is not an issue as they block current instead of encouraging it as MOV’s do.

Again, if you are questioning the effectiveness of Furman devices, I encourage you to read the full Wirecutter article and their testing methods. There’s no bone in that soup to pick.

OP:

If it were me, I’d 100% ask if they can repair just the amps. 😂  The amp is going to be a lot lighter and smaller than the whole speaker.

If you feel comfortable with a screwdriver you should be able to remove the sub amp and ship that alone to them. When you do, measure the resistance of the subwoofer coil with any cheap multimeter, and talk to GE techs first. If they measure like a dead short or infinity you may have bad woofers as well.

Isn’t that what the fuse is for?

@12blistn

Checking the fuses is a great first step, but they aren’t really for protecting against incoming voltage surges. They are for protecting from shorts inside the gear. A damaging surge voltage may be 400V or higher but never exceed a few microamps, therefore no breaker or fuse tripping.  For the same reasons the NEC now requires homes be surge protected in addition to the required breakers.

A power surge is often high voltage but relatively low total power and current. Takes a sustained current flow for that fuse to heat up and trip but it only takes microamps and milliseconds to burn out a semiconductor. Sometimes the static electricity you generate walking across a carpet can be enough, and would be if semiconductors were out of their protective enclosure.

When I was in manufacturing we’d even bring in humidifiers in addition to static straps to prevent chips from dying from static discharge during assembly and test. To put this in proportion, it takes about 15 milliamps to interfere with your hearts beating, but that tiny bit of high voltage current can wreak havoc on a lot of electronics.

@robert_1  - Sounds very squishy.

Furman makes units for 15 A and 20A circuits.  Hope that's high enough.

@markcasazza

I quote pi.ai:

Both Panamax and Furman are owned by the same parent company, Linear, LLC, which is a division of Nortek, Inc. In 2006, Panamax acquired Furman Sound, and since then, Furman has operated as a second brand within Panamax.

When I last looked, some Panamax high end surge protectors included the Furman features of SMP and LiFT.

You are right that a lot of snake oil in this business exists which is why I always turn to the Wirecutter article which is, as far as I know, the only third-party survey of surge protectors which actually includes 5kV surge testing.

The Furman brand has long been associated with professional sound gear as well as home gear.

@jea48 - Furman with SMP will protect in both cases you mentioned.

It uses series mode protection (SMP) which has no activation time. My understanding is that they rate surge protectors for 5kV surges specifically because the expectation is that anything over that will jump incoming insulation to ground before it can enter the home. The series mode protection slows the event down long enough for the over voltage breaker to trip if still needed, such as the case in a continuous over or under-voltage.

I want to point out that we’re deep into the "what if" situations that are not the major cases. I remember when seat belts became required by law, everyone focused on "what if a plane lands on my car? What if a dinosaur swallows my Eclipse? How is the seat belt going to help me then?" despite the fact that seat belts converted about half of fatal car accidents to non-fatal accidents.

Living in South Carolina near the ocean I’ve had at least a dozen serious surge events some of which were near-misses but most were not. The OP has already discovered that the 2 devices not surge protected in his stereo were what went, I’ve had the same happen here, but with a laptop. I’ve also had my Furman’s turn off due to over/under voltages caused by nearby transformer events.

You are right though, the A’gon poster who had the roof blown off his living room was probably not going to be protected. How many of us have actually had that happen vs. the more moderate cases?

And let us not forget solar flares!

@bigtwin Never said otherwise, but most damaging surges are not direct, and I'm definitely not home about 80% of the time there's lightning around the home. 

@wharfy  We've discussed Brickwall /Zerosurge, above.  I'd suggest you look at the Wirecutter article for pros and cons.

@bigtwin Not really a difference for surge protection between Type 1 and Type 2 except where it can be installed. Being type 1 is not necessarily better for your computer or stereo because they still have similar clamping voltages, but if you can install it closer to the meter you may have better luck mitigating an external surge. In theory though a Type 1 has to use more rugged parts than type 2. See linke, above.

The Siemens BoltShield I have happens to be rated for both, and still has a relatively high clamping voltage and some activation time.

In terms of meeting the NEC requirements for new home construction either location is acceptable, so long as the SPD is rated appropriately, meaning, as far as the NEC is concerned they’ll offer similar protection for your equipment regardless of where it’s installed.

You may also install both kinds, and there’s some merit in installing them at sub-panels when the sub panels are particularly far away from the main panel.

So, I return to my main thesis, that the most important part of a surge protection strategy is having a whole house surge protector AND a highly effective plug in surge protector for your sensitive gear.

Once you have done that I think the question of whether your whole house unit should be at your meter or panel becomes less important.

@ozzy  I read, I think, that the engineer who did the Furman SMP/LiFT tech went to work at Audioquest.  Maybe I'm mistaken?

I want to point out something about the old Tripp Lite Isobar units.  I have at least 3 of them running around my home.  The one feature they lack is that they don't turn off when protection is spent, but the newer Tripp Lite models often do.

Check the Wirecutter article quoted above for specifics because it's one feature they list.

I absolutely believe in whole house surge suppression, however I also know that they are not enough, so I have to reply when I read:

Far superior solution and problem solved. 

The issue is clamping voltage and speed.  Whole house suppressors let much more voltage than the best surge strips.  They are meant to save your house wiring as much as your major appliances.  I know from experience of losing a laptop that they don't do very well for sensitive electronics.

@dweller, none of the Furman’s with SMP are sacrificial though they do include an MOV for a rare edge- case surge. It almost never has a part to play in the surge protection.

Arguably the Zerosurge/Brickwall units are completely not sacrificial, but they also let more voltage through and have one wierd case they don’t cover. I talked to an engineer at length about this, and I’m afraid I forgot the full explanation. SMP, he argued, is a series mode protection with lots of similarities to Brickwall / Zerosurge PLUS an MOV just in case. So long as the SMP does it’s job the MOV never activates.

Bottom line is after the discussions I had PLUS the Wirecutter testing consider the Furman as reliable if not more, and more cost effective.

If you own a Brickwall or Zerosurge already it's an excellent choice and will give you many years of service.  It is only those users who are shopping new that should consider the alternatives.

@tvad I encourage you to read the Wirecutter reviews, which goes deep into how they tested and why Furman with SMP beat Brickwall. They also mention a number of other makers who have outstanding surge protection to what was common 20 years ago.

The actual surge performance, plus features and relative price makes it really hard for me to recommend Brickwall or ZeroSurge instead.

I won't argue that Brickwall, or Furman have lower clamping voltages than the whole house units however and that having a whole house unit won't protect the most sensitive devices.

OP:

That is not a surge protector.  It's a very expensive power strip.  There's zero protection there.   Read the description carefully.  It doesn't even have a breaker or fuse.

Best,

Erik

As I type this we have a strong but narrow thunderstorm moving through the area and yes, I’ve turned off the stereo and HT but I’m still online, allegedly working and studying. 😀 

Besides lightning we've lost 3 transformers nearby over the last two years for non weather related issues.  So, sure tell me all you want  to about how macho it is to run your amps straight into the wall, I don't care.  😀

@immatthewj - I was speaking to how I protect all the different devices in my home that are considered sensitive. Not all have the same needs.

For my stereo and home theater I use Furman. In terms of just surge protection and AC noise filtering I trust Furman more than anything else in my home, that’s why the most expensive gear I own is on Furman protectors. I also trust Tripp Lite for some things and for my PC I trust APC as being reliable enough.  My subwoofer is an exception because it's not located in a place convenient to the Furman. The sub is on a Tripp Lite.

For most other devices I use Tripp Lite except in the case of my Wifi router and PC when I use a UPS and rely on it’s built in surge protection. I use a UPS on my wifi router to keep my internet up even when the power goes out.

The only devices I have on a UPS are those I need to keep working even when the power goes out. I often work remotely, and power does go out here multiple times a year so my PC and my Internet have to last me at least through a video conference call. On the other hand, I really don’t need my stereo to be guaranteed to stay up through a typical blackout.

PS - I also have a whole house surge protector which protects the dozens of directly attached devices like my fire alarms, wifi enabled light switches, and GFCI outlets. They all have a rather high clamping voltage (~ 400 V/leg or higher) so they are no substitute when it comes to PC’s and stereo gear.  Furman clamps around 160V.  See the Wirecutter reviews for more specifics.

Hi OP: I meant to say that I use a Trip Lite everywhere except my PC because I have an Uninterruptable Power Supply.

Because Furman makes so many products it’s important to note whether they have SMP (Series Mode Protection) and LiFT (Linear Filtering). These are the two features to look out for surge protection but there are more expensive models with features like switched outlets, voltage regulation and power factor correction.

The PST-8 is around $200 and has both SMP and LiFT.

According to the latest Wirecutter testing they provide the lowest let-through voltage of any surge protector they tested, which included ZeroSurge.

@dweller ’s approach is good but here in SC I’m not always home when thunder rolls by. I absolutely turn the breaker off when the thunder gets close, but that’s probably only about 30% of the time there have been storms around my home.

^^^^^^^^^

This, exactly this.  It isn't just the repair cost, it's the lifting and shipping.  An amp/ speaker that's blown sounds a lot worse than one plugged into a surge protector.

I wrote about this here: