All Routers/Switches Fried

[jerzguy]

So I have a very vexing problem going on that I hope the experts here can help solve, because I certainly cannot understand what happened.

We were out on vacation, and while we were out a thunderstorm went through our area. I believe we lost power for a short while as well. I got a call from a neighbor that my alarm was going off. He could not figure out if it was the security alarm or the fire alarm...this alarm turned off in 15 mins. A friend who had the key the house came in to find that everyone was ok (no fire or anything) but on going to the basement found out that all my networking equipment had stopped working. I have a cable model connected to a router that feeds 2 8 port switches. I also have hardwired ethernet cables going all over the house. All my basement devices are connected to an APC UPS, which was still working and did not show any signs of a power surge.

Thats where this all starts. Apparently, within the house, I also lost power to the garage (a burnt out GFI) and the breakers for some receptacles had tripped. All cable boxes (3 of them) in the house were also on the fritz. My friend thought it was a surge (since he had experienced something similar) and that was it. The alarm was probably the security alarm (thunder) and it was not able to call out since the phone (from the cable company) was down as well.

So when I returned from vacation this week, my head started to hurt as I looked at what else had happened (which my friend could not have found):
- All network switches in the rest of the house were burnt out
- Every electronics i own is connected to a surge protector but no surge protector indicated a surge yet all equipment was burnt out.
- A couple switches turn on, but their Internet-In connections dont work
- My phone base (one of these Panasonic multi-handset ones) was not working (no power)
- A couple in-wall ethernet cables do not have any network signal
- The TV in my family room is not acccepting any external inputs (all HDMI inputs and network input is not working)
- TV in guest room has one HDMI port not working
- TV in bedroom cannot connect to the internet (the in-wall Ethernet port has signal)
- And finally, my cooktop's auto igniter does not work and the hot water boiler had turned off (both have ignition mechanism, so could there have been an electrostatic current or lightning come through ?)

So as you can see this is a very complicated scenario....and I have started my shopping for new equipment however, I'd love some of you experts out there to brainstorm with me, what you think might have happened here....no single theory (power surge, phone line surge, lightning) makes sense here.

Any thoughts most welcome and sorry for the long post, but I had to describe what's going on.

Thanks !!

 

[John Connor]

OMG! Sounds like a surge to me. I'm trying to understand what you wrote. You said equipment connected to a surge protector was fine?

 

[dave_the_nerd]

Yeah, dude, your house got hit by lightning. I've lost some stuff that way before.

One time, where I worked, a lightning strike a few blocks over nuked the cable system over a large area. Killed a couple of signal boosters and a few of the TVs we had hooked up.

Maybe homeowners' insurance will cover some of the damage?

 

[jerzguy]

Thanks !
@John, I meant that the surge protectors themselves were OK, however any equipment connected to them (network switches, AppleTV, external HDD etc.) are all gone. I know for one surge protector, the power bricks for my HDD are shot. TVs were all on surge protectors also...TVs turn on and screen lights up, however they dont accept any external inputs (HDMI or ethernet).

@Dave, lightning is a possibility and unfortunately my insurance company does not cover anything that was lost as a result of a surge I will try to open a claim and have an inspector come in though....

Thanks for your quick responses. The damage is done, but I am trying to determine some logic behind what might have happened. The varied nature of the damage is very perplexing !

 

[John Connor]

Wow! So surge protectors don't do jack. I guess if it was a direct lightning strike you're SOL. They do make lightning arresters though. They are a few hundred and are good for one strike.

I have a felling if we talk about surge protectors and lightning arresters too long Westom and --Bud will find their way into this thread. They are all over the net about surge protectors.

 

[jerzguy]

@John, does not look like the Surge protectors did anything at all ! In researching some more, this could be something by Dish Network dishes might have introduced....a lightning strike (very small intensity?) captured by the dish, transmitted through their cable (and my regular cable is "tied" to the dish cable) and from there it just went across my low voltage wiring, damaging everything in its path. Also explains why HDMI ports are fried on my main TV since Dish was connected to it on one of its HDMI ports.

Oh well...more research to do...lightning does seem be a strong finalist to what happened here

 

[Fardringle]

I something similar happen a couple of years ago in a small office that I support. Lighting hit the ground near their building. In their case, the surge went through the network lines (not the power lines) and actually melted a couple of the network cables inside the walls. It was a nasty mess to clean up, but definitely sounds a lot like what happened here.

 

[paul878]

@John, does not look like the Surge protectors did anything at all ! In researching some more, this could be something by Dish Network dishes might have introduced....a lightning strike (very small intensity?) captured by the dish, transmitted through their cable (and my regular cable is "tied" to the dish cable) and from there it just went across my low voltage wiring, damaging everything in its path. Also explains why HDMI ports are fried on my main TV since Dish was connected to it on one of its HDMI ports.

Oh well...more research to do...lightning does seem be a strong finalist to what happened here

Is your dish cable grounded before it enters the house?

 

[imagoon]

Everything you described sounds like a grounding issue. You may want to test the house grounding at the panel and then on the various circuits. Normally a direct strike leaves burns. If the disk was struck it would be pretty obvious since there would be scorch marks on it.

You also could have had a ground surge if the bolt landed close to but not on the house. What happens is during the time the strike hits, earth ground locally shifts quite a far way from the "0V" everything expects.

Check over the house for anything that look melted (shingles etc) as you may have damage to the structure in those areas if it was lightning.

 

[thecoolnessrune]

You were probably using cheaper MOV-based suppression (like most cheap surge protectors), that do not effectively protect equipment.

Surge suppression is a multi-pronged approach.

First, you need to be sure you have an effective lightning arrestor at your service entrance. This is the heavy cables that are near your home whose sole purpose is the collection and diversion of lightning strikes at your home, into the ground. This is similar to the lightning rods you see placed on commercial buildings designed to collect lightning strikes to those points and diver them to ground. This ensures that even during a direct lightning strike to the house, the most powerful strikes will have most of the damaging energy transferred to ground.

The second line of protection is your service entrances. You should ideally have a SPD (Surge Suppression Device) installed right next to your Service Panel to direct lightning strikes that run partially, or directly, over power lines. Needing suppression greater than 50 Amps is usually unnecessary as even in a direct power line strike will usually deliver less than 25% of the lightning's power to the service entrance. Greater than a 50 Amp SPD breaker risks a slower reaction time to lightning hitting the service entrance.

You also need lightning arrestors at other service entrances, like for coaxial and phone service lines. These connect directly to the point where the service enters the premises. You also must ensure that water and gas lines running into your home have been properly grounded.

Once you finish with the first 2 large things, the remainder of the vast majority of lightning strikes should have been reduced to far more manageable levels. For affordability, regularly replaced MOV-based surge suppressors can work for non-important equipment. Important and expensive equipment should be moved to Series based surge suppression. Most major electrical power works companies produce these kinds of protectors, including APC, Tripp-lite, Eaton, Schneider Electric, etc. These types of suppressors are more expensive than the ones you find in a store (usually around $100-150 for 8 outlet models), but are much more capable to effectively block the surge spikes that would enter a well-protected home, and you also avoid poising your ground line like MOV-based surge suppressors will do.

As a last note, keep in mind that you need to put lightning arrestors on any home cabline that makes a journey outside, like if you have an Ethernet Cable running outside the house, or a coaxial running alongside the house to get to another portion. A lightning arrestor would need to be put on each end of the cable and properly grounded.

As long as a multi-faceted approach is taken to lightning suppression, with primary focus given to the home and service entrances, then most surges that make it into the home are manageable.

 

[jerzguy]

I checked around the house and in the attic for any signs of a lightening strike but did not find any. I also confirmed that both the DishNetwork and Cable wires are attached to a pretty solid ground that is attached right next to be electric meter on the outside.

How does one test the grounding of the house ? Do I need to get an electrician to come check it out ?

In terms of the surge protectors I have, they are the pretty standard one - APC, Belkin, Monster and the like ? And each of them did cost a pretty penny at one point....are there more advanced surge protectors out there ? I did look at the panel level surge protector and am considering getting one installed.

Thanks all for your comments and feedback !

 

[thecoolnessrune]

There are two major types of surge protectors for electronic equipment, MOV-based Shunt protectors (the most common), and Series based surge protection. MOV-based protectors attempt to redirect power to the ground conductor, but MOV conductors are like an alkaline battery. They only have some many surges they can stand. This is why many of the surge suppressors have a "fail" light (which often doesn't work). Many small surges over the live of the suppressor "use up" the surge capacity just as if one large surge hit it. Over time, your surge suppressor may be compromised when a surge larger than the "capacity" of surge suppression that remains comes through your power line.

Series Mode suppressors use inductors, capacitors, and resistors to actually suppress a surge, rather than divert it. In the occurrence of a surge, the surge is slowed down using inductors. Now no longer a surge, the excess current is drained over a neutral connection. This prevents ground wire poisoning, and can withstand limitless surges, as long as power handling capabilities are not exceeded.

If your surge suppressor contains data on RF frequency suppression, then it is likely not MOV-based.

While your cable may be connected to a ground, that is not necessarily surge arresting. While a surge may have an easier, less damaging path to the earth with a dedicated ground, without surge arresting, a charge is still likely to continue into the cable section. A proper arrestor with the arrestor connected to ground is a fairly cheap and substantial upgrade, as many surges come in over cable and telephone lines.

 

[ronbo613]

Sounds like a lightning strike. Something similar happened to my cousin; lightning struck a pole near his house, the electric surge traveled through wires underneath his driveway and pretty much burned up all his electrical devices as well as most of the house's wiring. There was no burning of the house's structural materials, no visible signs of fire.
A powerful electrical surge as the ability to cross open circuits, like a switch in the "off" position, so most types of surge suppression are not effective.

 

[Cerb]

Wow! So surge protectors don't do jack. I guess if it was a direct lightning strike you're SOL. They do make lightning arresters though. They are a few hundred and are good for one strike.

I have a felling if we talk about surge protectors and lightning arresters too long Westom and --Bud will find their way into this thread. They are all over the net about surge protectors.

Surge protectors protect against surges in the same way a bouncer protects a bar. If a gang wants to bust down you door, you're SOL. If a rowdy drunk or pissed off dude wants to start something, your bouncer takes care of it. Typical MOV protectors are for common surges, often internal to your home, less so than lightning. But, they also can sometimes shunt that and protect your stuff, if you're lucky. Protection that is more sure than shunting is uncommon and expensive.

Jerzguy, that was all Thor's way of saying, "hi." Lightning won't need to directly hit your house for your house's equipment to help provide a good grounding path, so you may never see any telltale signs of the strike itself. It's not at all uncommon for phone or cable lines to be the carriers of the strike's energy, and Ethernet allow it to spread. If your house is wired well, especially if it's not too old (with GFI breakers, it surely isn't), most of it should 'see' your house wiring as a much poorer path, except from coax and Ethernet to ground (but think of it the other way, which is more important: from your ground(s) to the coax, then into the air).

Not long ago, a client of my father's (yeah, I 'grew into' IT ) office got struck. The owner was there when it happened, so there wasn't much doubt (flash, bang, lights went out). It fried the cable modem, switches, a few NICs, a few PSUs, and a few mobos. Luckily, the servers were unharmed, as was every device not on the LAN.

+1 to everything thecoolnessrune has said.

 

[westom]

In terms of the surge protectors I have, they are the pretty standard one - APC, Belkin, Monster and the like ? And each of them did cost a pretty penny at one point....are there more advanced surge protectors out there ?

Now let's add facts and numbers they forgot to mention. Take a $3 power strip. Add some ten cent protector parts. This sells in WalMart for $10, or from high profit manufacturers such as APC and Belkin for $25 or $60. Monster has a long history of identifying scams. Then selling an equivalent product with more expensive looking paint for even $120. Some charge even higher prices by calling it a power conditioner.

A protector adjacent to appliances can only block or absorb a surge. Read each's specification numbers. How does its hundreds or a thousand joules absorb destructive surges that are hundreds of thousands of joules? Yes it is a surge protector. But only for surges that typically cause no damage. How many recommended protectors by ignoring spec numbers?

That was for absorbing a surge. How does its 2 cm protector part block what three miles of sky could not? Again, how many recommendations also provide numbers? No numbers is a first indication of a scam or junk science reasoning.

Return to what was originally introduced in elementary school science. What does lightning seek? Lightning is a connection from a cloud maybe five miles to earthborne charges. So an electrically shortest path is three miles down to earth. And four miles through earth to those charges.

Franklin demonstrated this. Wooden church steeple is an electrical conductor. But not an excellent conductor. So 20,000 amps (lightning) through poor conductive wood creates a high voltage. 20,000 amps times a high voltage is high energy. Church steeple damaged.

Franklin connected a lightning rod to earth. A connection to earth (more important than the rod) is an excellent conductor. So 20,000 amps (lightning) through a good conductor creates a near zero voltage. 20,000 amps times a near zero voltage is near zero energy. Structure not damaged.

That was protection of a structure. Same applies to protection of appliances ... which you did not have and a majority who replied did not know about.

Household appliances are less conductive. A direct lightning strike far down the street is incoming on AC mains to all appliances. But not all are damaged. 20,000 amps only goes hunting for appliances that make a best connection to earth. Therefore create a high voltage inside those appliances. A high surge current times high voltage means appliance damaged. Damage because a homeowner all but invited lightning to go hunting inside.

Informed consumers (even 100 years ago) connected a surge low impedance (ie 'less than 10 feet') to single point earth ground BEFORE that current can enter a building. Best protection systems do this with a hardwire. Other utilities that cannot connect direct to earth are connected via a 'whole house' protector. Then a near zero voltage is on a path to earth. 20,000 amps times a near zero voltage is near zero energy. And no current inside the house hunting destructively for earth via appliances. 20,000 amps times a near zero voltage outside means near zero energy inside. No appliances damaged. Because the surge need not be anywhere inside the house.

So, does a 'whole house' protector do protection? Of course not. Protection is always about where hundreds of thousands of joules harmlessly dissipate. Protection is provided by THE most important component in any protection system - not a lightning rod or any protector. Protection increases when earth ground and its lower impedance connection is upgraded. Lightning rod and protector are connecting devices to what does protection. A protector only does what a hardwire does better.

And again, protection means no surge current anywhere inside the building. Then superior protection already inside each appliance (including dishwasher, furnace, GFCIs, dimmer switches, clocks, etc) is not overwhelmed.

What does that say about your Belkin, APC, and Monster products? A 'whole house' solution costs about $1 per protected appliance. And protects from all types of surges. Your plug-in protectors (that did exactly what the manufacturer said it would do) costs tens or 100 times more money. Did you forget concepts originally taught in elementary school science? Did you believe advertising, hearsay, retail salesmen, and wild speculation of claims without numbers? Did anyone say where hundreds of thousands of joules harmlessly dissipate?

Review what was damaged. A surge incoming on AC mains must also have an outgoing path to earth. Incoming on AC mains. Outgoing to earth on cable modems due to surge protection required exist on that cable. Inspect it. Your best cable protection is a hardwire from that cable to a unique ground - single point earth ground. All four words have electrical significance. Damage is usually on that outgoing path. Cable modem is more likely damaged on its cable connection - due to a surge incoming on AC mains.

Same applies to telephone appliances. All phones already have surge protection as required by FCC, NEC, and other industry standards. Required for longer than any of us have existed. How many even knew earthed protection is already on cable and telephone? How many notice that satellite dish installers routinely violate codes that require them to both earth a dish AND earth where its coax cable enters a structure. Again that important number. Incoming cable must connect low impedance (ie 'less than 10 feet') to an earthing electrode also used by cable, telephone, and AC electric.

What numbers are significant to a 'whole house' protector? Lightning is typically 20,000 amps. So a minimal 'whole house' protector (from other companies with better integrity) starts at 50,000 amps. Since effective protectors remain functional even after direct lightning strikes. Again, only useful recommendations always include numbers.

Above is an executive summary. Especially since earthing (not protectors) define protection. Protectors are simple dumb science. So simple that many consumers instead spend tens or 100 times more money on protectors that do not claim protection from the other and destructive surges. Those obscene profit protectors do not have and will not discuss the most important component in every protection system: single point earth ground. Protectors are simple science. The 'art' of protection is earthing. We have not even discussed that. A lightning rod or protector is only as effective as its earth ground.

Summarized is a 'secondary' protection layer: a properly earthed 'whole house' protector. All are strongly encouraged to inspect their 'primary' protection layer. Each protection layer is not defined by a protector. Earth ground is where energy dissipates; what defines each protection layer. A picture demonstrates what every homeowner should also inspect:
http://www.tvtower.com/fpl.html

Direct lightning strikes without damage have been routine for over 100 years. But a majority never learn any of this due to advertising and hearsay. Many forget that honest answers are quickly identified by numbers. Many even forgot what was taught in second grade science. Then spend tens or 100 times more money on products from Belkin, APC, Tripplite, Panamax, or (worse) Monster. Welcome to an introduction of surge protection 101.

 

[John Connor]

SEE! Told you this guy would chime in! He's all over the Internet blabbing about surge protectors. Don't respond. Next up, --Bud.

 

[Binky]

Some surge protectors come with a warranty for connected equipment. You should check into that. Also, your credit cards may add a year of warranty protection to purchased items (don't say anything about lightning!). Assuming you can get a few items covered in some way, it might help pay for a few of the lost items.

 

[imagoon]

SEE! Told you this guy would chime in! He's all over the Internet blabbing about surge protectors. Don't respond. Next up, --Bud.

The power of Google alert and cut and past!

 

[paul878]

Some surge protectors come with a warranty for connected equipment. You should check into that. Also, your credit cards may add a year of warranty protection to purchased items (don't say anything about lightning!). Assuming you can get a few items covered in some way, it might help pay for a few of the lost items.

I wonder, has anyone ever successfully file a claim with Surge Protector company?

 

[Binky]

I wonder, has anyone ever successfully file a claim with Surge Protector company?

I'm sure they have a million ways to claim its not their fault, but why not try?!

 

[KingFatty]

Could the lightning have struck the network wiring?

I don't see how you can protect against that. It's nice to be educated about good surge protectors and stopping issues coming from the power lines/wiring, but sometimes nature just says too bad, and finds another way to screw you by coming into the house another way.

Did you go up on the roof and look at the actual satellite dishes to see if they were scorched anywhere? Do you have network wiring that is right next to the HDMI wiring on the TV or whatever that got damaged?

I'm just trying to think of commonality in all your broken stuff, that includes HDMI and network ports.

 

[Cerb]

Could the lightning have struck the network wiring?

I don't see how you can protect against that.

Optoisolators, with some distance between the outside and inside. To maintain digital sat/cable signals, cheap ones won't do, and you'd probably be looking at $300-500, unless prices recently came down quite a bit.

 

[jerzguy]

Thank you all for your comments and suggestions.

@King, yes I did check the dishes installed (they are actually at eye level right next to the deck so easy to inspect) and did not see any signs of a lightening strike. My house is only 4 years old and I have HDMI wires and ethernet wires running in the walls. Every TV has an ethernet port and 2 or 3 HDMI cables within the wall behind it. I continue to discover new damage. For e.g. today I found out that my PS3 is no longer transmitting video on the HDMI port (the PS3's power comes from my amp which was switched off, but an ethernet wire was directly attached to the PS3 from the switch). Apparently the PS3's HDMI out is gone and it seems that HDMI wire that connected the PS3 to the TV is also gone (only that HDMI wire, the other 2 are OK). Interestingly, the PS3 is emitting video on the 480P AV wire.

From a wiring perspective, my dish and cable wiring travel together for the most part and I have a little "network closet" in the basement where all my ethernet wires (~20) come together and are bundled with the coax cables. So very possible that whatever surge came through jumped between wires.

At this time, i can safely say that anything that was connected to a wall jack (via a power point or ethernet line or phone line) has suffered damage and is not operational. And thats a sizeable damage for me....lots of $$$ to spend to get back to where i was at a little over a week ago !

Thanks all !!

 

[thecoolnessrune]

I always pegged opto-isolators as fairly low-bandwidth devices, hence why you usually see them in the audio transmission, and serial transmission market. In fact, I thought even modern ones were limited to something like 50Mb/s optimistically / channel. I don't know if you'd find one for a full bandwidth cable system (at least, none that I know of!)

That being said, when it comes to ethernet, unless you absolutely need PoE from end to end, then it's always better to run protected fiber between two outdoor sections. Lower noise, longer travel distance, and lightning doesn't care about it (keep in mind though if you have ungrounded, exposed metal conduit protecting it then lightning will care about that!)

If you do need POE (Power over Ethernet), then using a properly grounded surge arrestor on each end of the exposed Network cable is best practice. Ideally you want to use a combination unit that not only utilizes SAD (silicon avalanche diodes) for picosecond clamping ability, but also GDTs (Gas Discharge Tubes) to clamp high surges (such as lightning strikes). They run about $50-$100 each and you need one on each end of the cable. You also need to ensure you have a properly earthed grounding source in immediate proximity to each protector.

Coxial is difficult to apply solid protection to, because the wide bandwidth needed to carry phone, tv, and internet signals means that SADs are ill suited to be used in the suppressors. Instead, you have to rely primarily on GDTs, that are able to operate on a wide rand of bandwidths with little issue. Again, proper grounding of the suppressor is key, so as to ensure little energy as possible makes it to the GDTs, which, while fast when compared to human perception, are far slower than SADs to clamp, and also deteriorate and require replacement like MOVs do.

That last note brings back a common point I've been making that I'd just like to reiterate. I believe after my post earlier, even Westom touched on it, though it did it in an abrasive fashion and was incorrect about one layer protecting all the others.

So again, I want to reiterate how important a multi-layered approach is when discussing home (or business) protection. All of the surge suppression systems we've been talking about could never tolerate a direct lightning strike. A Series Mode power surge protector might have a *chance*, but chances are it too would be taken out by a high energy lightning strike.

The key to power suppression in a home or business environment, is making sure that your house is properly grounded at each level you're trying to protect. That means making sure lightning always has a quick and painless route to earth. This starts at the house level, and making sure you have a system in place to route lightning strikes along low resistance routes directly into the ground. This is often done with lightning rods and guide cables, but there are several ways to approach it. By doing this key first step, you're attempting to ensure that the only surge suppression your data lines have to take care of is side flashes from a strike, and indirect surges from power lines or other transient sources. Since power cables can carry a lot of surge energy, this is where whole house SPD devices come into play. Now this is largely redundant, because the clamping voltage of whole-house SPDs is often near 700 Volts, which is still damaging to sensitive equipment and makes it so that in-home surge suppressors usually suppress or clamp before the SPD shunts.. But the idea here is to effectively limit the duration large surges are coursing through your house. This is especially important for your Series protectors which are actively attempting to suppress power surges. The sooner you get that surge stopped from coming into your home, the better. While whole house SPDs use MOV's, this is acceptable because of two main reasons. 1, the MOV's used in these systems are HUGE, and are far more resilient to heavy surges compared to the ones in your little power strip. They are also in the form of replaceable modules, so you the SPD doesn't "expire". 2, The primary downfall of Shunt-based surge protectors like MOVs is that they "poison" the ground with surge energy when they are diverting a surge. But this isn't an issue to service entrances because you're diverting the energy back *outside* of your premises, not *inside* your home ground wire system. That's why using Shunt-based devices on whole house systems, network cables (GDTs and SADs), and coaxial cables (GDTs) is acceptable, because it's expected that you'll be shunting that energy directly to an external ground, not inside your home.

Once you have the two largest surge receiving entrances "handled", smaller devices in the form of Series mode surge protectors, and Ethernet shunts, and coaxial shunts, all take care of the much smaller transients that may enter those cables. As long as you have the first two steps taken care of and done properly, no direct surges from lightning should have any interest in entering these cables, as there are more accessible grounds with less resistance.

That brings the last point, is that when you have all these grounds, you must ensure that all the grounds are properly bonded so that each path has an equal resistance back to earth. This step is crucial, as if the grounds aren't properly bonded, all you've done is make another hotspot, maybe even in a place you'd least want it. What happens if you end up making your Ethernet Shunt ground the least resistive path to earth? You've just directed the next lightning surge straight into your network. While it is possible to do all the bonding yourself, a certified electrician familiar with local codes is a far safer bet.

That reads to me like a lot of rambling, but I hope it's of help to some! I understand that there's always a price / performance breaking point, as you can only do what you have funding for, but in an ideal world, we need to take care of all the above in at least one form. If I had to recommend just a *couple* of things, I recommend getting a Series suppressor on your important home equipment, and properly grounding surge arrestors on your satellite coax.

 

[Cerb]

Last I looked, a couple years ago, they weren't exactly cheap, and were powered, so my guess is they weren't just transformers and photodiodes, and might have only been good for for one range (analog cable TV is what they were for, and I can't say I looked into much else).

If you can get coverage on your insurance, that would the simplest thing to do, since, without designing the building to be a good lightning rod, it will be a lot of work to go from so-so resistance to surges to good resistance to surges, and a major lightning strike shouldn't be a repeated occurrence.