Surge protection

[Isetech]

Now that we all understand the difference between lightning and surge protection, what are your thoughts on where surge protection should be installed.

1/ The main DB, at the main switch (non-essential supply) ?

2/ The Sub DB, at the main switch, after the neutral earth bond (essential supply or inverter output) ?

3/ The DC combiner box for the panel cables ?

The reason for the questions, if the building has solar panels and the panels are earthed, bonded and have an earth spike, are class II surge arrestors the correct units?

Do you need surge protection after the inverter or only in the main DB?

[Dylboy]

My opinion yes because we are doing surge protection and not lightning.

A direct strike if it was a class 1 or 2 but with no proper lighting protection standards will do nothing.

When I spoke to DHEN about this he said you can fit a type 1 and Type 2 for extra measure but make sure they are coordinated (basically same brand in a nutshell)

Earthing of Panels for the sake of earthing can now cause an extra conductor to carry a surge so bonding or earthing a panel in most cases is useless.. unless a metal roof that is already earthing on AC side etc then bonding of panels to roof for same equipotential is then needed.



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[Dylboy]

Surge protection in main DB and then Surge protection for PV i.e has + and - as they have better contacts and a lot of stuff I can remember that PV surge is for the PV strings only for when they pick up current that is induced for example near by storm


I must add I am not qualified in this field but it is what I have learnt and learning.

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[kavesh]

Hi all

Hope you don't mind me asking a question on this thread. Its related to surge protection.
I have a 3kva inverter installed.
I spoke to the electrician and asked what is the best defence against against power surges. Effectively he said that nothing will save you. You can install surge protection in your DB and if the power surge is big it will go past the surge protector and still damage your appliances and inverter.

I would really appreciate some advice on this. I spent a good some of money installing the invertor and need some sort of protection. Yes there is a fuse fitted but if I recall its more to protect the batteries.

Thanking you in advance.

Kavesh

[GCE]

A good quality surge arrestor will protect equipment , if have just seen it again when a neutral was stolen on Friday evening .

For good quality class1 and 2 combined expect to pay around R1 000 per pole - So +/R2K for a single phase supply

[Isetech]

I agree with the person who mentioned that the lightning/surge protection will not protect you against a direct hit or a really big bang on the council. I can share a few stories about insurance claims going into the 100's of thousands. I also have a few pics of installations where we have installed the best quality surge protection, trip connects and all those nice things, blown to pieces.

However if you want to spend some money on surge protection to reduce the risk of damage due to transient spikes, heavy load switching during load shedding etc.

Surge protection in the main DB will help reduce the risk of damaging sensitive electronic equipment, installing surge protection on plug tops for example will also help. Add a trip connect device which will protect against neutral cable theft.

More important than our advise, check with your insurance, if they require surge protection, best you have it installed.

From past experience, insurance will cover until the first bang., then they will send you an email with a clause which no longer covers you unless you have surge protection.

Beware, make sure you read the clauses related to surge protection, most insurances companies will not cover you unless it is lightning related. No storm on the day, no cover. You will have to claim from your local supplier.

[Dylboy]

Is a trip connect device like those TV safe units ?

I thought a surge protector will help with a Neutral stolen?

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[Isetech]

I have a couple 3 phase units on sites where we have low voltage issues, but can be used for over voltages caused by neutral cable theft.

We still have sites which are FUBAR after "faults on the supply". In some cases the units are melted and welded closed. They do work, because I have had cases where there has been cable theft and the sensitive equipment was not damaged.

https://surgeprotection.co.za/products/12-01035-trip-connect-3p-v2

https://surgeprotection.co.za/sites/default/files/specsheets/12-01036_rev0.pdf

[Isetech]

If you scratch around on the internet you will find a product that looks identical to the trip connect. I dont know if the clearline product is rebranded.

[Dylboy]

Ahhh yes ok, you have mentioned it before sorry, I didn't quite click. But also good reminder of the product!

Very cool stuff that thank you.

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[Derlyn]

As far as load shedding is concerned, I'm still convinced that my fridge safe together with contactor is the answer.

My power comes on a couple of minutes after everyone else's and I'm sure the spikes caused by switching on are long gone by the time mine comes on.

I have noticed that led lights are prone to failure because of spikes from loadshedding. How do I know this you may ask.? I have had many clients complaining that led lamps were blowing left right and centre. I suggested that when there's loadshedding to switch off the lights and only to switch them on again after the power has been turned back on. End of problem.

[Isetech]

The spikes are recorded as load shedding is switched, on both, on and off. The bottom line is load shedding is doing a lot more damage than we identify. Its good busy for maintenance sparkies. A drive in a machine could cost in excess of R100 000 .

Rather focus on your insurance, make sure you understand your cover and check that there is no clause which voids surges caused by anything other than lightning. The assessor will check the weather report for the day of the claim. Dont say you weren't warned, I see the insurance companies handing out proper wedgies to loyal customers who pay and think they are covered.

Insurance companies are about collecting monthly revenue not paying out share holder profits.

As far as load shedding is concerned, I'm still convinced that my fridge safe together with contactor is the answer.

My power comes on a couple of minutes after everyone else's and I'm sure the spikes caused by switching on are long gone by the time mine comes on.

I have noticed that led lights are prone to failure because of spikes from loadshedding. How do I know this you may ask.? I have had many clients complaining that led lamps were blowing left right and centre. I suggested that when there's loadshedding to switch off the lights and only to switch them on again after the power has been turned back on. End of problem.

[Isetech]

The moral of the story, just like you pay the school teacher, teller at the bank and "insurance broker a monthly fee, make sure you get them to go through your policy step by step even if it means they must do a site visit and 5 hours to verify everything in the document and highlight everything you are not sure about. When that wall collapses or the drive pops, they will refer to the document you signed, its all there in the document.

[kavesh]

Thanks for the comments guys, lots of food for thought.

My current policy only covers R10k which is nothing sadly. I was asking my broker to increase the cover and she mentioned that the insurance companies are loading premiums for higher cover, which can make it challenging for the lay man to accept.
I was also told that the insurance companies are insisting on surge protection, but as far as I have read my policy does not stipulate this, but will confirm with the broker again.

Seems we are getting screwed all round....

[Derlyn]

Fortunately, I've never had insurance.

Not once have I paid for other people's stuff to be replaced.