Power surges and insurance

[ians]

So you take out insurance for your business premises and wahla ...you insured...as we know that is not the case...thats why they use and pay assessors so well...to figue out a way to enforce the small print...clause on page 604 (which you didnt get to while reading the document emailed to you after you signed and sealed the deal)....some might say but that is what insurance brokers are there for...from my experience more for the commission than than the service.

I have some bad news for you...the old lightniting/surge protection in many cases has been revised...if your insurance company even entertains a lightning damage claim... then the assessor will first check the weather on that day ...and just show face as a formality to make you think you have a chance...but in reality you pretty screwed...in many new cases...they dont even entertain your claim.

So what is the big deal...it cant be that bad you have a small power surge and it takes out a few electronic items....R 10 k small change for repairs a couple day you pi$$ed off with the insurance and you back to paying the premium.

What i have been experiencing lately are a few R 100 000 plus claims being rejected due to not being lightning damage ...a simple weather report and your beer money or massage at the local Thai ladies is out the window.

some insurance companies wont even consider your claim if you go to all the trouble of installing surge protection...from my experience ...a waste of time and money unless done correctly.

in most case it is a neutral conductor stolen for a sub station which in turn ...elevates the voltage to in excess of 600 volts (the most common cause of surge related incidents i am called out to investigate) which will blow the crap out of most electronic devices or just chip away at a device ...ever wondered why you hard drive just stops working...and even cause a fire...as i have seen in a few cases.

I am busy with 2 incidents ...the estimated cost to repair R270 000 (double story office blocks)

A note...in this day and age ...everything has an electronic PC board.

What what would i recommend to try prevent this from happening...

Fitted inside the meter box or next to the incoming supply...

A trip connect ( a device used to monitor incoming voltage)
surge arrester (correctly rated and installed)
a contactor (which drops out if the voltage drops below 180 v or above 250 v ...this parameter can be set for more sensitive equipment)

Surge protection at the main DB.

The majority of damage done to electrical installations is caused by power surges from the municipality ( i dare you to try claim from them...if you have managed to claim please let us know ...i have folder full of claims) neutral conductors being stolen...excessive volt drop and surges...in one area in Durban i have recorded voltages as low as 170 volts...notified the council they send an electrician out he uses a duspol test and informs you that there is power

[Andromeda]

Hi Ians, I agree wholeheartedly, but at that point I guess you have eliminated the risk and that begs the question why pay a premium to cover an event that can't materialize? Or can it still?

[adrianh]

Is there a way to protect the property cost effectively at the main db board?

[GCE]

Surge arrestors definitely reduce the risks and I have seen it on an installation where the neutral was stolen in the sub.WE have class 1 and 2 combined units at the main DB and at the Sub DB class 2
Supply is 1200Amp and sub DB at 500Amp, The majority of the equipment is electronic and has class 3 installed.

The generator does not have surge arrestors in its panel and every time the neutral link is stolen the generator charger or changeover relay fails due to excessive voltage.

We have now fitted a relay monitoring the voltage and feed a shunt on the incoming CB if the voltage goes out of spec .

[adrianh]

Surge arrestors definitely reduce the risks and I have seen it on an installation where the neutral was stolen in the sub.WE have class 1 and 2 combined units at the main DB and at the Sub DB class 2
Supply is 1200Amp and sub DB at 500Amp, The majority of the equipment is electronic and has class 3 installed.

The generator does not have surge arrestors in its panel and every time the neutral link is stolen the generator charger or changeover relay fails due to excessive voltage.

We have now fitted a relay monitoring the voltage and feed a shunt on the incoming CB if the voltage goes out of spec .

...I mean for the man in the street to protect the house.

[GCE]

The same applies for the man in the street
Fit Class 1 + 2 surge arrestors and a relay to monitor voltage - Use the relay to drop out a contactor

Good Quality Surge Arrestors will go a long way in protecting you

[ians]

The simple answer ...no...that is why you need insurance ...one which isnt full of small print and clauses excluding "power surges"...some areas are affected more than others... there are lightning stat charts available...like anything its a numbers game...and insurance companies have the stats to prove it ...hence the exclusion of power surge cover in many cases.

You can attempt to reduce the risk... by installing "lightning protection"at various levels...MOV's ...trip connects and other products available on the market...however the voltage supply in SA (the ones i have tested...using a fluke 435) are so unreliable...in some cases you would think a generators was feeding the building...in certain areas in and around Durban you cannot even install a trip connect with the voltage set to the widest span (170-260 volts) unless you are happy to sit without power 2-3-sometimes even 4 or more times a day...while you wait the delay period to reset.

I am not saying "lightning protection" doesnt work for power surges...just make sure you still have insurance cover for the day the surges gets past everything you have installed...trust me when i tell you it does...as we have just learnt the expensive way... in one case the insurance company have decided to pay a small percentage (25%)...they at least sent and assessor to verify we had taken steps to protect the installation... for the other building the customer was just told... power surge damage is excluded in the policy.

Neutral and cable theft is as common in SA as hijacking/murder and all the other criminal activities...all i am saying is check your cover.

Make sure the person who installs the protective devices understands what they are doing...it is easy to go to the wholesaler and pick up a "lightning protection device" and fit it anywhere in the installation...will it do the job...it might.

Understand what it is you are trying to protect and rather focus on installing the correct devices where they are best suited for the application.

Dont be fooled by thinking surges only enter the property via the electricity supply.

[ians]

You can buy these units online...it is a good start to protecting your home/shop/factory.

Single phase (for the home)

https://surgeprotection.co.za/products/12-00407-trip-connect-single-phase

3 phase (I have some of these units installed on site since 2009)

https://surgeprotection.co.za/products/12-00409-trip-connect-3p-programmable

used with the trip connect.

https://surgeprotection.co.za/products/12-00418-db-boards-3-phase

I have also used surgetek products...however they dont have a trip connect unit...but their surge protection devices work and they have a person with a lot of experience in this field.

http://www.surgetek.co.za/

At the end of the day it all boils down to what it is you need to protect and how much you are prepared to spend... or just make sure your insurance company covers.

I went to the dentist and notice he had spent a couple of hundred thousand rand on a fancy new X ray machine... i asked him how much he had spent on a clean stable protected power supply...zero.. nada not a cent... "i have insurance" ....good luck with that.

[ians]

This is a complete single phase unit.

https://surgeprotection.co.za/products/12-00853-active-power-monitor-tripconnect-100

As you can see if you start scrolling though the catalog ...it is not cheap.

Clearline use to have cover for the device you connected...ie a computer ...you could "register" the unit and if the computer was damaged due to a surge... you could claim X amount (not sure of the amount but it was worth while) ...i am not sure if they still offer the cover ...will check and get back to you.

[adrianh]

This is a complete single phase unit.

https://surgeprotection.co.za/products/12-00853-active-power-monitor-tripconnect-100

As you can see if you start scrolling though the catalog ...it is not cheap.

Clearline use to have cover for the device you connected...ie a computer ...you could "register" the unit and if the computer was damaged due to a surge... you could claim X amount (not sure of the amount but it was worth while) ...i am not sure if they still offer the cover ...will check and get back to you.

Very nice - R2k isn't bad considering the protection that it offers.

As an aside - but along similar lines. I have a nice big UPS on my PC. It works really well and it kicks in every time I forget to buy electricity :-)
but... I have found a really interesting thing with the UPS - When the compressor starts the UPS kicks in. The compressor is of course on a different circuit in the garage and the PC is in the office. I never realized that those motors create such a huge spike that goes all over the house. I really wonder whether equipment doesn't get damaged due to those sort of spikes. Let's say by chance the compressor and the vacuum cleaner are turned on simultaneously - won't the effect be really really bad?

[ians]

Very nice - R2k isn't bad considering the protection that it offers.

As an aside - but along similar lines. I have a nice big UPS on my PC. It works really well and it kicks in every time I forget to buy electricity :-)
but... I have found a really interesting thing with the UPS - When the compressor starts the UPS kicks in. The compressor is of course on a different circuit in the garage and the PC is in the office. I never realized that those motors create such a huge spike that goes all over the house. I really wonder whether equipment doesn't get damaged due to those sort of spikes. Let's say by chance the compressor and the vacuum cleaner are turned on simultaneously - won't the effect be really really bad?

Old compressor aircon units are also bad news...your lights would dim... it causes a volt drop not a surge in power...they suck electricity.

We had an incident where every morning a 5 am the entire factory would "blink" causing all the VSD's to reset and a whole lot of other issues...the operators would have to go around and restart everything...it turns out there was a huge compressor which switched on/off causing this "blink" i got to site at 3 am...setup the recorder and waited...at 5 am on the dot ...there was the glitch on the screen ...and you heard the machine all go down.

As soon as you start adding Aircons...pool pumps...a Jacuzzi...etc etc ...a little more consideration should be taken into the electrical installation...in most cases people dont even consider equipment installed in a domestic installation...everything is considered as general...2.5 for plugs...1.5 for lights etc etc

Something to consider ...using a VSD to either soften the startup current or to fit a 3 phase motor (not sure if you already have a 3 phase compressor) i have a few customers who have down scaled and moved back home...unfortunately they have 3 phase equipment and only single phase power at home... simple... just use a 230 single phase to 400 3 phase inverter...way cheaper than upgrading to 3 phase power.

[AndyD]

... I have found a really interesting thing with the UPS - When the compressor starts the UPS kicks in. The compressor is of course on a different circuit in the garage and the PC is in the office. I never realized that those motors create such a huge spike that goes all over the house. I really wonder whether equipment doesn't get damaged due to those sort of spikes. Let's say by chance the compressor and the vacuum cleaner are turned on simultaneously - won't the effect be really really bad?

As a rule of thumb most single phase motors that are direct-on-line will draw about 5x their run current for a very short period of time on start-up. This would include fridge, vacuum cleaner, air-con, irrigation/borehole/pool pump etc.
The large current draw causes the voltage to drop significantly and not just on that circuit. Your UPS is probably detecting this voltage dip and jumping into battery mode. These voltage dips can cause all sorts of operational issues and reliability issues for electronics.
The high start current only usually lasts for a few miliseconds so the chances of two motors starting simultaneously is very small in a domestic environment. If it did happen the voltage sag would be more pronounced. Unfortunately under-voltage protection relays don't help with this issue, they're more effective at protection against longer duration low-voltage events. Good practice final-circuit design helps also load balancing if you have a 3-phase supply.

[adrianh]

As a rule of thumb most single phase motors that are direct-on-line will draw about 5x their run current for a very short period of time on start-up. This would include fridge, vacuum cleaner, air-con, irrigation/borehole/pool pump etc.
The large current draw causes the voltage to drop significantly and not just on that circuit. Your UPS is probably detecting this voltage dip and jumping into battery mode. These voltage dips can cause all sorts of operational issues and reliability issues for electronics.
The high start current only usually lasts for a few miliseconds so the chances of two motors starting simultaneously is very small in a domestic environment. If it did happen the voltage sag would be more pronounced. Unfortunately under-voltage protection relays don't help with this issue, they're more effective at protection against longer duration low-voltage events. Good practice final-circuit design helps also load balancing if you have a 3-phase supply.

Ahhh OK, so it is the voltage drop that causes the problem.

[ians]

Ahhh OK, so it is the voltage drop that causes the problem.

I would suggest you do a few calculation and check cable sizes etc...incoming voltage...mains connections etc...my compressor was blinking the lights in workshop...it turns out the fuse on the pole outside my property had a bad connection.

Even with a single phase motor starting...it shouldnt cause your UPS to switch(depending on the unit it should switch at around 180 volts ...if you have 230 volts (the standard in SA) that would mean it is a 50 volt drop...i would be scratching around for loose connections...looking at cable sizing...cable lengths...loop and line impedance tests at the compressor isolator ...etc etc.

[Justloadit]

I have 2 few products which address this issue with respect to Surges.
One can not ever guarantee that after installation there will be no failures.
One of the characteristics of surge arresters that they fail after a number of accumulative surges.
In other words when a surge occurs, the surge material cause a short circuit over a certain voltage, if the surge was of sufficient energy which the surge arrester can handle, only a partial part of the arrester is damaged, and is disconnected from the terminals by nature of the surge arrester material. Enough of these surges, and the arrester will no longer operate and fails completely.
In the case that there is too much energy, then the surge arrester material basically fails as a short circuit and hopefully the circuit breaker trips.

However with respect to SANAS, the surge arrester once failed, must be removed from the circuit to prevent fires after the surge arrester material has become a short circuit, and sufficient current can flow with out tripping, but could cause fire. So to fall into line, ther is a special thermal fuse that is installed in a number of surge arrester types, which once the material reaches 110Degrees, the thermal fuse will pop, and remove the surge arrester device from the circuit.

Taking advantage of this factor, LEDs can be placed which light up when the surge arrester is operatinal, and once the fuse pops and the surge arrester is no longer protecting the site, the LED is extinguished.

This is the reason that you must check your surge arresters regularly or after a storm or supply issues to see if the LED is on, and replace immediately to maintain protection.

Another interesting fact is that the more arresters are placed on the mains lines, the better the lines will be protected, with out damage to the surge arresters, as each arrester will absorb a portion of the surge, thereby reducing the amount of heat the surge arrester handels.

In this case the more the merrier.

My 3P5W Surge protection, has an added feature/option, in which the Earth to Neutral voltage is measured, and if it exceeds a preset value, then it will disconnect the contactor supplying the load.