Isolator Main Breaker Question

[MJCM]

This is our setup.

Now the problem was, that the 63A would trip often, turn on a pump, and the 63A would trip.

Our Sparkey, said that the 63A is too soft "ohn".

The problem was solved by buying a 63A from Siemens. The original 63A was from the Haco brand.

Any thoughts?

 

TiA

Edit: Forgot. This house is only less then 1 year old.

[Crossy]

How big is the pump??

 

What "curve" was the first unit? If it was "B" then the startup surge from your pump may have tripped it. That said I've not seen a B curve unit here; C curve seems to be the standard.

 

It's always possible that the Haco one was actually faulty.

 

In our time BS (Before Solar) we never managed to trip our 63A incomer even with Madam's 3HP irrigation and 2HP lift pumps running.

[MJCM]

Thx DC.

No idea about the curve, but the pump is just a 450W Hitachi Inverter House pump.

 

Our first thought was that Ants got in but Sparky checked, on top of the house etc etc and no ants found in the wiring or the pumps.

My Guess is that the Haco was faulty, as well, because after changing it for the Siemens no issues at all. *Better Quality maybe also???*

We have the same Haco in our own house as incoming and no issues *knock on wood* just yet.

 

I have ordered a 63A ABB just in case for our own House

[Muhendis]

That picture doesn't look right.

In the event of a lightning strike nearby, The resulting EMP (electromagnetic pulse) would trip the 20A thingy but maybe not the 63A one which would result in the EMP having fun around the house wiring.

Maybe the drawing is not quite right?

[bearded_bluto]

On 1/7/2025 at 10:42 PM, MJCM said:

Our Sparkey, said that the 63A is too soft "ohn".

The problem was solved by buying a 63A from Siemens. The original 63A was from the Haco brand.

Any thoughts?

 

TiA

Edit: Forgot. This house is only less then 1 year old.

That is a big pump if it eats ~14,000 watts on single phase. Was it a rcbo type breaker? Maybe there is a small fault in the motor? Edit: Nevermind, just read rest of thread, 450 watt motor...

[Crossy]

5 hours ago, Muhendis said:

That picture doesn't look right.

In the event of a lightning strike nearby, The resulting EMP (electromagnetic pulse) would trip the 20A thingy but maybe not the 63A one which would result in the EMP having fun around the house wiring.

Maybe the drawing is not quite right?

 

Nah, the MCB is waaaaay too slow to trip on the EMP, it won't even notice.

 

MCB several milliseconds to think about operating, lightning pulse sub microsecond.

 

[carlyai]

Muhendis you had me a bit worried then cause mine is the same.

What MJCM and I haven't done (one of them roundtuits) is install another MOV (metal oxide varister) on the neutral as well.

Me thinks that a near lightning strike will raise the earth and neutral voltage for a poofdeenth of a second as well.

I think I remember seeing a Crossy home cct. and his incoming neutral has a MOV as well

 

[MJCM]

We have this same setup in three houses with the first build is well over 7 years old and never had an issue with this same setup.

The Distribution board consists of all Schneider components with RCBO's

 

Ps: The stickers need work 55555555555

[carlyai]

5 hours ago, MJCM said:

We have this same setup in three houses with the first build is well over 7 years old and never had an issue with this same setup.

The Distribution board consists of all Schneider components with RCBO's

 

Ps: The stickers need work 55555555555

You may never have a problem from lighning strikes, but then one day you do. I think best to install a MOV on the neutral as well. If that's what you mean.

[MJCM]

I got this drawing from someone on the board, and I will ask his advice on this.

My knowledge doesn't extend that far.

Thx

Edit: If there are lightning strikes in the area, I disconnect everything and lower all MCB's just in case.

[carlyai]

3 minutes ago, MJCM said:

I got this drawing from someone on the board, and I will ask his advice on this.

My knowledge doesn't extend that far.

Thx

The only reason I mentioned it is I'm fairly sure a home circuit I saw from  Crossy had a MOV on the neutral as well.

I'll have a look for the pic. 🙂

[Muhendis]

On 1/10/2025 at 5:19 AM, carlyai said:

Muhendis you had me a bit worried then cause mine is the same.

What MJCM and I haven't done (one of them roundtuits) is install another MOV (metal oxide varister) on the neutral as well.

Me thinks that a near lightning strike will raise the earth and neutral voltage for a poofdeenth of a second as well.

I think I remember seeing a Crossy home cct. and his incoming neutral has a MOV as well

 

As far as I am aware those MOVs actually do protect the neutral also.

However the earth and neural are connected together outside the house at regular intervals. 

Something like every third or fifth pole I believe.

However, the EMP is very fast. In vacuum it travels at the speed of light.

It's a bit slower in air and a lot slower in electrical conductors.

Also the further away you are from it's generation, the less it's effect.

It obeys the inverse square law in that respect.

But the speed of the rising edge or start of this pulse is, for all intents and purposes, instantaneous.

Conductors that carry electricity to your house have this thing called resistance which will attenuate the voltage of the EMP.

These conductors also have something else call impedance which will slow down the speed of the rising edge of the EMP but it is still very very fast.

So the longer the conductor, the less effective is the speed of the rising pulse.

What I am leading up to is the length and thickness of the earth wire from the MOV to the ground rod. this needs to be as short and direct as possible to minimise the EMP voltage drop.

[MJCM]

2 hours ago, Muhendis said:

What I am leading up to is the length and thickness of the earth wire from the MOV to the ground rod. this needs to be as short

Length approx 1-2 meter,  and thickness 25mm² NYY

[Muhendis]

1 hour ago, MJCM said:

Length approx 1-2 meter,  and thickness 25mm² NYY

Mine is more like 3M and 10mm² and I am happy with that. Yours is even better..........🙂

The fly in my particular ointment is the grounding of the solar array. My solar MOV's are inside the combiner box which is on my car port roof. The MOV earth is bonded locally to the stainless frame of the panels which is then bonded to the concrete carport. That should give a reasonable sort of earth connection, but in addition to that I have a 10mm² connection between the solar panel mounting frame and it's own dedicated ground rod length about 7 Metres. I think there must be ways of testing these ground connections but, cheap charles that I am, I don't fee any urge to go out and buy the kit to do it.

[carlyai]

4 hours ago, Muhendis said:

As far as I am aware those MOVs actually do protect the neutral also.

However the earth and neural are connected together outside the house at regular intervals. 

Something like every third or fifth pole I believe.

However, the EMP is very fast. In vacuum it travels at the speed of light.

It's a bit slower in air and a lot slower in electrical conductors.

Also the further away you are from it's generation, the less it's effect.

It obeys the inverse square law in that respect.

But the speed of the rising edge or start of this pulse is, for all intents and purposes, instantaneous.

Conductors that carry electricity to your house have this thing called resistance which will attenuate the voltage of the EMP.

These conductors also have something else call impedance which will slow down the speed of the rising edge of the EMP but it is still very very fast.

So the longer the conductor, the less effective is the speed of the rising pulse.

What I am leading up to is the length and thickness of the earth wire from the MOV to the ground rod. this needs to be as short and direct as possible to minimise the EMP voltage drop.

Respectfully I think it's difficult to circuit analyse what a lightning strike will do or where it will travel. 

I used to work at a TV transmitter on top of a large mountain and we used to get struck regularly many times. If you walked out of the main building your hair would stand up and the air was noisy, Ssssshhhhh, like just about to break down.

Most times the strikes would do no damage, then others would damage a piece of equipment, but not the same TX or RX (we had multiple microwave links, base stations and TV transmitters).

I was once working on a link when bits of resistors went shooting past my face after a loud strike and bang. Frightened me fartless.

Engineers tried to rig up a circuit to count the strikes and it always got to 1 and disintergrated.

Lightning strikes do funny things and are unpredictable.

Lightning struck near our house a couple of years ago and took out 6 LED fluoro type lights in part of the garage but not the other 4 LEDs.

[MJCM]

if there are lightning strikes in the area, I always pull the plugs on all our electronic devices and also "trip" the isolator and also "trip" all the breakers in the Distribution board.

Does that help, or does it just plunge us into darkness without being effective? 🤔

[carlyai]

I'm sure that's the best thing to do, but what happens when you're not there?

Probably replace the supply MOVs regularly even though they still show green.

Or do what Crossy did and place small MOVs on power switches to soak up any spike the supply MOVs missed. Attenuate the lightning spike.

That's just my feeling, no technical definition to do this.

[carlyai]

4 hours ago, carlyai said:

I'm sure that's the best thing to do, but what happens when you're not there?

Probably replace the supply MOVs regularly even though they still show green.

Or do what Crossy did and place small MOVs on power switches to soak up any spike the supply MOVs missed. Attenuate the lightning spike.

That's just my feeling, no technical definition to do this.

I've got a diesel genset. If the lightning gets bad I turn off the main breaker and use it.

Only ever happened once.