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petetherock

Adding lightning protection to your house

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Friends

I’m keen to add a lightning surge protector

Should I add it to my main DB or gate ?

how much protection should I get? Someone said 40 kA

I’m using a three phase 63a system right now with one dedicated line to my Hifi den

the other two go to the rest including the pool, pond and other stuff. 
 

thanks

 

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Hi Pete

The first entry of surge current is at the gate post where the electrical meter is located. If you are having 3 phase 63A, you will see 4 cables (L1+L2+L3+N) L=Live and N=Neutral. The 3 Live wires are Black, Grey, Brown. The Neutral is Blue.There is also a PE (Protective Earth)!which is green/yellow and this PE will be connected to your earth rod/electrode.

At the incoming (gate post), you need Class 1 SPD(Surge Protection Device)with preferred 25KA per phase. So with 3 phase + Neutral, it will be 4x25kA=100kA rating. This SPD is preferred to be installed after the MCCB but before the RCCB. If your LEW want to install after the RCCB, you may encounter sensitive tripping of the RCCB unless your LEW can find a ‘S’ type RCCB which has a time delayed tripping function. This SPD can be connected in either parallel or kelvin connection. Do discuss with your LEW.

At the DB, only Class 2 SPD is required. You will need minimum 10kA per phase protection which means 40kA total. This SPD needs to be install upstream of your DB’s MCCB & RCCB. Connection is either parallel or kelvin connection. 

To enhance protection to your Hi Fi equipments, you will further need a Class 3 SPD. This SPD should be installed as near to your equipment as possible. This is preferred to be just before your Hi Fi’s voltage regulator/stabilizer if you have one. Based on your description of using one phase dedicated to your Hi Fi system, install this Class 3 SPD after your wall power outlet and before the voltage regulator. You can install as many Class 3 SPD as required depending what equipments you need to protect. One power outlet=1 SPD. Connection in parallel or series. If series, there is a limit current of 25A. If connect in parallel, will be much higher. 

In summary, you will need:

1x Class 1 SPD, 1x Class 2 SPD per DB, multiple Class 3 SPD. Cost of SPD in descending order: Class 1>Class 2>Class 3. 
Hope these helps. 

 
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It seems my main DB is full, so the target is at the incoming gate post..

is it possible to add one outside of the DB I.e. adjacent to it?

that’s my main gate and level three DB

thanks !

FF61EF20-ED56-47EC-8315-58D2C6DE104E.jpeg

08B7A0B6-1FCE-4CAD-BB13-1D3A0AD50C7E.jpeg

 

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Also , a friend was told to use a 20kA times three SPD 

I can’t seem to find a 100KA one and the price goes up quickly beyond 40kA …

any idea of costs for these devices?

Edited by petetherock
 

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7 hours ago, petetherock said:

It seems my main DB is full, so the target is at the incoming gate post..

is it possible to add one outside of the DB I.e. adjacent to it?

that’s my main gate and level three DB

thanks !

FF61EF20-ED56-47EC-8315-58D2C6DE104E.jpeg

08B7A0B6-1FCE-4CAD-BB13-1D3A0AD50C7E.jpeg

The first picture should be your main gate incoming DB (or referred as incoming electrical panel) because it has your incoming mains and your meter. 
It will be difficult to fit the SPD outside the incoming main gate electrical panel due water ingress issue causing trips or safety concerns.  Further, there is a requirement wire length for each phase with connection joint from the MCCB outlet joint to the SPD inlet joint PLUS the length of the earth wire to the ground bar(shown in picture with 2 blue non conducting foot mount) total not to exceed 50cm. Once this maximum length is exceeded, there will be a drop in effectiveness to divert the surge current to earth due electrical inductances. 
From what I can see in the first picture, there is still space available but may require re-positioning the MCCB (small white box with some red colored ON/OFF toggle lever) This looks like an old ABB brand item. 
 

 

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7 hours ago, petetherock said:

Also , a friend was told to use a 20kA times three SPD 

I can’t seem to find a 100KA one and the price goes up quickly beyond 40kA …

any idea of costs for these devices?

Our 3 phase system is using TT connection and usually referenced as 3P+N. So you will need a 4 pole device for all connections. In layman term, you need 4 inlet connections and 4 outlet connections for any single device. Unless you split each phase with 1 device. Example will be the incoming circuit breaker as shown in your earlier post. In that picture, you can see 3 small white boxes and a smaller black box. The 3 white boxes each house a single phase breaker (63A or 100A depends) to connect one of the 3 LIVE phases. The black box is a direct connection of the Neutral phase which don’t need a breaker. 

So, if you can find a 20kA times four SPD, it can be used too. Make sure the SPD has 3P+N=4 connections. 
For the SPD installation inside you house’s DB, you can use 10kAx4=40kA.

Do note: Class 1 also known now as Type 1, Class 2 also known as Type 2 and Class 3 known as Type 3. They are basically the same classification for the SPD.

Type 1 will be expensive and not easy to find as most house owners don’t know it is highly recommended. It is not mandated by PUB when they sign off the main incoming electrical panel after installation by electrical sub-con. Personally, I don’t think PUB care if the house gets a lightning strike(taken care by the lightning protection system signed off by BCA)and in turn causes a surge current in the house’s electrical circuit and killing/shortening life span of your expensive equipments/household items. As long as the basic requirement(63A breaker and/or 300 mA RCCB)  is there, and most important of all, the meter is running to bill owner at the end of the billing cycle, PUB won’t care. Anything damaged inside the house is under owner’s charge. The 63A breaker is to prevent overload/surge current at the sub-station from entering your house or cause fire at the incoming electrical panel cluster which you can legally take action. 

A Hager brand Type 2, 40kA total, 3P+N will cost around $250-$270 each, available at some local electrical supply shop. I am using one each for my 2 in-house DBs.

Type 3 sold at electrical supply shops were China made and I don’t trust. You can go online e-commerce to search for DEHN or Phoenix Contact, both brand made in Germany. Typical e-commerce price of Type 3 in the region of $150-$200 each. 

For Type 1 you can look at DEHN. But DEHN mostly comes with Type 1 combined with Type 2. In theory, if this device is installed in your incoming electrical panel, it will arrest the Type 1 and Type 2 classified surge but because of the long cable length that run from your incoming panel to inside your house’s DB, some Type 2 surge (caused by lightning) will be picked up by this long length of cable and cause some surge at your in house DBs. One solution is to install another Type 2 only SPD at the in house DBs. They are relatively cheap at $270 max to protect your motor driven devices like water pumps, air con compressors, fridge compressors, fans motor etc. And because they are in the secondary level Type 2, they will last a long time. 

DEHN Type1+Type2 will cost around $600 from e-commerce but local distributor selling at $1000+ with installation another $500+. 
 

Note: Type 3 SPD is for protection of electronic devices and need to be as close as possible to device to be protected. Am analogy is those extension sockets with surge protection integrated. Example brand like Belkin. Because it’s a all in one commerce product, the small SPD integrated into the extension bar will not be able to neutralize the Type 3 surge effectively. 

From my own experience, I have noticed a marked reduction in motor driven noise (fan motor, fridge compressor) in my air con fan coils, fridges, and my network cluster. But it could be just me. 
 

 

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Some points I learnt
- when wiring your home, plan some redundancy, eg one line shorted, but the electrician was able to tap another line for my pond power and lights

- use good cables, it's worth paying more

- plan for expansion, so get a good sized DB box

- tighten the various cables when you open the box

- place a light in the DB box or a torch nearby

 

 

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my electrician used cables from Sigma.

I had wanted to split the DB into one for each floor initially but ended up not doing it and put it inside a store where my network equipment rack is. The main consideration of not having split DBs was how/where to hide the DBs.

torch light is subjective la. Nowadays our mobile phones usually near to us all the time so can use the phone's LED as torch.

how much you ended up paying for all the SPDs?

 

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Pete, the SPM440E is a Type2. Did you managed to install any Type1?

Further, the 3 LIVE & 1 Blue NEUTRAL cables tapped from the MCCB inlet connection looks very long. Any one phase cable length + PE cable looks like more than 50cm. There will be a certain percentage of pass through for Type2 surge and if you don’t have Type1 installed, there will be 100% pass through of Type1 surge.

 
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Thanks for chipping in, this was the easiest for him to find at the moment, so I hope it works..

Let's see if it stops the trips at my pond.

However he also found that it might be the outdoor switch that is the issue.

The other area that trips is when there is a direct strike on my roof and there's one switch that trips in the top floor. Hope the SPD in that DB helps.

I haven't got the bill yet from my guy, so I can't share the damage yet, thanks for asking snoozee...

I was hoping there will be some storm before I go back to work, but so far it's been peaceful haha... 

 

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11 hours ago, petetherock said:

How about these ? My friend is using them in each DB 

image.thumb.jpeg.e5023b5ee753626c194cd9a23fbbc4af.jpeg

I asked around previously from electrical supply shops locally and was shown this particular brand ‘kam’ for sale. It’s made in China. Price around $13 each and only single phase available, not 3P+N.

 

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Is it easy to replace a bad SPD?
I saw some sites suggesting replacing it every two years... I can't imagine asking a LEW to come so often... especially if there isn't any fault.

If there is a strike and does it always turn red? I can't imagine having to keep a few of these standby... if it's easy to swop, maybe I can use a Type 1 in future in the same spot.. 
Thanks

 

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