Lightning.

[Bobster.]

Big electrical storm in Jhb this afternoon. I remember one very loud discharge, and there are now reports that it hit somewhere near where I live. 

And now dozens of reports, several in my street, from people who lost all power, have lost circuits in their homes, and/or have suffered damage - notably wifi routers. 

OK... Some of this needs to be verified. The largest Fibre operator in the area seems to be having major issues. I assisted one neighbor whose EL has been tripped, and who was caught out by the breaker lever only falling a little rather than going all the way down. 

But in my street an intercom, a computer screen, a screen connected to security cameras, an actual computer, some external down lights (on a patio), several 5V power supplies. 

Jikkel! Can it really cause such chaos? Is this lightning itself or lightning hitting power lines? 

[JayMardern]

Everyone imagines trees catching fire when hit directly; but indirect affects are often more far-reaching.

 

A nearby strike can induce voltage surges onto power and data cables at quite a distance away. 

A cable meant to be carrying 5V that spikes to >50V as a result of a nearby strike can end up blowing the equipment on both ends. This is why it’s common to have low voltage equipment - like you mention - get taken out.

 

In my case, I’ve seen HDMI ports and Ethernet ports - both designed to operate at low-voltage - get destroyed by strikes nearby.

 

I’m in JHB as well - this arvie was nuts; it promoted me to power everything down and drop the PV and AC breakers on my system…

[Bobster.]

1 hour ago, JayMardern said:

I’m in JHB as well - this arvie was nuts; it promoted me to power everything down and drop the PV and AC breakers on my system…

Thanks. So from that do I assume that the surge comes in on power lines? The surge you mention in data and low voltage lines is not electromagnetically induced? 

[JayMardern]

13 minutes ago, Bobster. said:

Thanks. So from that do I assume that the surge comes in on power lines? The surge you mention in data and low voltage lines is not electromagnetically induced? 

Disconnecting from mains AC was actually an attempt to shield from direct-ish strikes in nearby AC cabling that might be conducted to our house. A direct strike to the house itself would presumably jump the breaker regardless, though!

 

But yes indeed: electromagnetically-induced over-voltages (from indirect strikes nearby) will still wreck equipment that’s sensitive to transient high-voltage spikes, even if running off grid…

[FixAMess]

Every year for 3 years in a row, we had our PC equipment, printers, routers "burnt" by lightning...Everything connected to the telephone lines was blown. It turns out our neighbour had replaced the old Telkom wooden pole with a magnificent steel one, nicely painted silver and shining.

Since I've disconnected the telephone lines no more problems...

[Steve87]

The Deye & FreedomWon equipment are also not immune. I had a call out to investigate & the CANbus Comms also not functional because of a Surge due to a very close hit less than 50m away. Luckily we had 2 machine in parallel. The poor master took the damage so we reverted to Slave & master reallocation & we back on the road running again. The 15/12 FW both CANbus modules on the both BMSs dead. Battery still functional but no comms. Again we lucky we had another 2 x 10/8 to rely on for Comms otherwise we were dead in our tracks. 

I will report back on this because it's a Deye machine so let's test the RMA processes as well as the FW RMA which I'm confident will be a self repair or BMS swop out. However, knowing the fine print I think Lightning events are definitely not covered. Nothing will withstand our mother nature when she is angry & flashing her camera. 

[Bobster.]

A reminder that insurers have been increasing the excesses paybable for damage blamed on surges, no matter how caused. Some insurers will reduce the excess if you have proper surge protection installed into your DB, by a suitably skilled person who issue the necessary certificate. 

[Bobster.]

1 hour ago, Steve87 said:

The Deye & FreedomWon equipment are also not immune.

I noted a while back the guys who installed my system fitted surge protection on the lines coming down from the panels to the inverter, and on the mains input side of the inverter. I don't imagine this is infinitely protective, but it's better than a kick in the pants. Presumably this offers protection against surges coming through the inverter to the battery.

[Carl Anthony]

12 hours ago, Bobster. said:

Big electrical storm in Jhb this afternoon. I remember one very loud discharge, and there are now reports that it hit somewhere near where I live. 

And now dozens of reports, several in my street, from people who lost all power, have lost circuits in their homes, and/or have suffered damage - notably wifi routers. 

OK... Some of this needs to be verified. The largest Fibre operator in the area seems to be having major issues. I assisted one neighbor whose EL has been tripped, and who was caught out by the breaker lever only falling a little rather than going all the way down. 

But in my street an intercom, a computer screen, a screen connected to security cameras, an actual computer, some external down lights (on a patio), several 5V power supplies. 

Jikkel! Can it really cause such chaos? Is this lightning itself or lightning hitting power lines? 

@Bobster. you read my mind with starting this post, I was going to do it last night as well!

A few Sundays ago also had a cracker of a storm here in the West Rand, Constantia Kloof...had a few hectic bangs and then a really big one...it tripped the EL.
I flipped it down to "O" and back up to "I" and then went to check everything...some electronics and network equipment had taken the hit.

Luckily everything else was fine. Solar System was fine as well.

I then had Mammoth Electrical come out last week to install a CBI Surge Protector (got a COC for Insurance as well) to offer some protection moving forward...anyone have any experience with these? I know a direct lightning strike is a different story and will likely fry the surge protector along with everything else...but from a Surge perspective how good are these?

I thought I might see the surge in the Solar Assistant data but saw nothing...grid voltage and frequency no difference during that time

[Carl Anthony]

1 hour ago, Bobster. said:

A reminder that insurers have been increasing the excesses paybable for damage blamed on surges, no matter how caused. Some insurers will reduce the excess if you have proper surge protection installed into your DB, by a suitably skilled person who issue the necessary certificate. 

Yip, got told flat excess for surges = R5000 and if you claim now for any future surge claims a surge protector installed in the DB with COC will be required.

[Vaal]

NB please make sure what your insurance company's minimum requirements for spds are.

I was told it must have a 20/40kA rating with a IEC spec number. And it must protect the N also. Have you seen what is in the cheap spd's? A simple MOV between L & earth and N &  earth. 

Edited January 17 by Vaal

[Carl Anthony]

1 hour ago, Vaal said:

NB please make sure what your insurance company's minimum requirements for spds are.

I was told it must have a 20/40kA rating with a IEC spec number. And it must protect the N also. Have you seen what is in the cheap spd's? A simple MOV between L & earth and N &  earth.

Thanks for this @Vaal, need to verify and confirm with Insurance...they didnt specify the rating required when we were speaking. Hopefully the one I installed will suffice.

[TaliaB]

Lightning is a diffucult beast to tame. Previously being involved with Lightning protections systems in hospitals and petrochemical industries it is not an easy solutions and there is no guarantees of a fool proof systems especially in a direct strike. 

Let us have a look at diffrent types of SPD,s.

The three types of SPD
Type 1 SPD:
The Type 1 SPD is recommended in the specific case of service-sector and industrial buildings, protected by a lightning protection system or a meshed cage.It protects electrical installations against direct lightning strikes. It can discharge the back-current from lightning spreading from the earth conductor to the network conductors.Type 1 SPD is characterized by a 10/350 µs current wave and is used where lightning strikes commonly occur.
Type 2 SPD
The Type 2 SPD is the main protection system for all low voltage electrical installations. Installed in each electrical switchboard, it prevents the spread of overvoltages in the electrical installations and protects the loads against high voltage transients but is not always effective during lightning strikes.
Type 2 SPD is characterized by an 8/20 µs current wave.
Type 3 SPD
These SPDs have a low discharge capacity. They must therefore mandatorily be installed as a supplement to Type 2 SPD and in the vicinity of sensitive loads.
Type 3 SPD is characterized by a combination of voltage waves (1.2/50 μs) and current waves (8/20 μs).

External lightning protection works using air-termination systems that you install on the roof. As the name suggests, they intercept direct lightning strikes and channel them away safely into the ground. The basis for this is that the external lightning protection system is connected to the earthing and equipotential bonding via the down conductors. 
Hospitals have densely packed roof structures. These include, for example, components for heating, ventilation and air conditioning (HVAC), and lift shafts. This makes it difficult for engineers to place the external lightning protection in accordance with the specifications. 
The challenge for you: It is imperative that separation distances are maintained between the air-termination system and conductive metallic parts in order to avoid sparking. Due to the lack of space on hospital roofs, however, this is often difficult.The solution: HVI Conductors(High Voltage Insulated down conductors). By using these high-voltage-resistant insulated down conductors, you can disregard separation distances and still be sure that lightning currents are safely discharged to the earthing system. That is why HVI Lightning Protection is a reliable and space-saving alternative to conventional lightning protection systems. So the above SPD's combined into 1 unit used with air-termination systems make it relatively safe for damage by ground strike and direk strike. 

[Steve87]

Guys this info is great and much the same as @TaliaBi use quality Surge protection and this was fitted on the AC and DC sides. As others have noted, one cannot 100% protect from a very close range to direct hit. 

I have been struck twice with direct hits in my previous career in aviation. One was in a B737 and the other occasion in a B777. What was evident in both cases was the amount of energy released. It was like the sound of a Gun shot. It was humbling to say the least.  We lost absolutely nothing electronic on the flightdeck. What was very apparent was the entry and exit welded holes in the aircraft skin after we landed and could get a visual inspection done.

What has become very apparent in our homes is that the small low voltage equipment struggles with the sudden energy burst of the actual event. This client had Schneider Surge 3 phase AC protection installed on the Load side and Grid side. His panels have Noark DC Surge as well. 

@BritishRacingGreenwas also on site and has suggested that one can also add RS485/CANbus or Comms Surge protection. Maybe he can share some light for us. Its unbelievable how much care must be taken to avoid damage to equipment and it costs a lot of money but in the end one then begs the question: When is it ever enough or are we kidding ourselves ?

Also totally impossible to compare equipment without being in a lab and have access to crazy amounts of energy and even then its not the real thing.

Very interesting discussion...

[TaliaB]

Solar farms lightning protection by DEHN Africa see the lighting rods.

2 hours ago, Steve87 said:

RS485/CANbus or Comms Surge protection.

Quite some interesting protection devices available from DEHN Africa.

https://www.dehn-africa.com/en-za

[Steve87]

This also sold at Micro Robotics...

[Nicholas Strachan]

16 hours ago, Steve87 said:

Guys this info is great and much the same as @TaliaBi use quality Surge protection and this was fitted on the AC and DC sides. As others have noted, one cannot 100% protect from a very close range to direct hit. 

I have been struck twice with direct hits in my previous career in aviation. One was in a B737 and the other occasion in a B777. What was evident in both cases was the amount of energy released. It was like the sound of a Gun shot. It was humbling to say the least.  We lost absolutely nothing electronic on the flightdeck. What was very apparent was the entry and exit welded holes in the aircraft skin after we landed and could get a visual inspection done.

What has become very apparent in our homes is that the small low voltage equipment struggles with the sudden energy burst of the actual event. This client had Schneider Surge 3 phase AC protection installed on the Load side and Grid side. His panels have Noark DC Surge as well. 

@BritishRacingGreenwas also on site and has suggested that one can also add RS485/CANbus or Comms Surge protection. Maybe he can share some light for us. Its unbelievable how much care must be taken to avoid damage to equipment and it costs a lot of money but in the end one then begs the question: When is it ever enough or are we kidding ourselves ?

Also totally impossible to compare equipment without being in a lab and have access to crazy amounts of energy and even then its not the real thing.

Very interesting discussion...

I used to fly the 380 for Emirates and got struck on final approach into melbourne.Shat myself but all good on flight deck but pin holing on horizontal stabiliser

[Steve87]

On both occasions on my 2 events we needed an underpants change. One was on the descent into Lanseria in a Kulula NG on a mid summers night. Displays all went really bright because of the sudden flash from dark. A camera on the deck would have exposed 2 bunnies staring at the headlights of a truck. 

The 2nd event low level high speed Paris Charles De Gaulle, ATC: maintain high speed...we were 300+ knts just before reduction. Must admit the Cabin crew very switched on, came to check all was ok. With my last operator this was unusual, it's against company policy after sterile deck for them to bother. That event let us know we could trust that crew. Sometimes policy can kill you, be human, question the norm...

[JayMardern]

Does the addition of a lightning rod increase the likelihood of induced voltage spikes since it makes it more likely for a strike to be nearby (i.e. at the rod?)

That is, does putting up a lightning rod save one from the (always devastating) effects of a direct-strike, at the expense of increasing the possible effects of an indirect strike on low voltage systems (like blown Ethernet Ports/Can-Bus connections); since we now have more nearby strikes?

[Moffat]

Now and into the next week there's likely to be quite a lot of thunderstorms and a cyclone into Southern Africa so there'll be a lot of equipment to be replaced and audits for SPDs on a lot of installations or exposure where inadequate protection systems where put in. Sadly for some it will result in them having no fall-back plans to Eskom blackouts in the immediate aftermath. In truth, protections work to some level, but as already been said, a direct strike will do as it likes and cause havoc. Is there anyone with experience using midnight solar SPDs?

[Bobster.]

On 2024/01/16 at 11:28 PM, JayMardern said:

But yes indeed: electromagnetically-induced over-voltages (from indirect strikes nearby) will still wreck equipment that’s sensitive to transient high-voltage spikes, even if running off grid…

As I experienced this week. Big storms on Monday and Tuesday. I was sitting pretty (in my mind) because of all the protection on the AC and DC lines. But there was a flash of lightning nearby that tripped everything on my neighbour's DB, blew his electric fence, and also took out the circuit board that controls my garage door. Apart from the damage to the controller board, there is the business of the motor keeping on trying to close a door that was already closed and bending some fittings out of shape. 

[Jacques Ester]

Lightning strike on powerline feeding our shooting range. Popped all 3x 11kv arrestors at transformer. Popped the borehole pump controller box and the arrestor on the feed in side of inverter.

 

[PsyCLown]

46 minutes ago, Bobster. said:

As I experienced this week. Big storms on Monday and Tuesday. I was sitting pretty (in my mind) because of all the protection on the AC and DC lines. But there was a flash of lightning nearby that tripped everything on my neighbour's DB, blew his electric fence, and also took out the circuit board that controls my garage door. Apart from the damage to the controller board, there is the business of the motor keeping on trying to close a door that was already closed and bending some fittings out of shape. 

The way I see it, all these surge protectors are is to ensure that if something happens the insurance will pay out.

How much protection it actually offers, especially for lightning, I feel is quite little. Especially for a direct strike.

[Bobster.]

1 hour ago, PsyCLown said:

The way I see it, all these surge protectors are is to ensure that if something happens the insurance will pay out.

How much protection it actually offers, especially for lightning, I feel is quite little. Especially for a direct strike.

But for surges when power is restored after load shedding? That's why insurers want them, it seem to me.
 

[PsyCLown]

On 2024/01/31 at 5:56 PM, Bobster. said:

But for surges when power is restored after load shedding? That's why insurers want them, it seem to me.
 

I stand to be corrected, however a common SPD such as the CBI dual pole SPD (https://www.liteglo.co.za/shop/cbi-qfln-2-2-pole-surge-protector/) only does something if the voltage is 275v or higher.

 

I have one of these installed: https://electromannsa.co.za/shop-the-latest-affordable-gadgets-online/din-rail-over-voltage-current-and-under-voltage-protector-relay/

 

So it will disconnect the mains if the voltage is above or below the set points I have set. It also has a function to set over current limit but I feel that isn't as useful for me.

I feel one of these would be more useful if you are worried about high or low voltage which can happen in some areas around loadshedding time.

One evening I noticed the voltage went above 240v and that shut off the power to my inverter, once voltage was within range it waited the set 30 seconds and then restored power to my inverter. This happened twice that evening, which I noticed - however voltage issues in my area are not common I do feel safer with such a device.