Ground Fault make my MCB Tripped, NOT GFCI

Thread Starter

meowsoft

Joined Feb 27, 2021
462
Please Read Carefully... I Am Live In China... So No GFCI/RCD/RCCB/RCBO or Equivalent Is Mandatory, and There is No Anything GFCI/RCD/RCCB/RCBO or Equivalent Is Installed In My System, From Utility Is There Only Two Wire, Neutral and Phase, Transformer That Feed My Home Is Single Phase, and Only Supplied My Home
My Ground Rods Is 3 meters deep, 1.5 meters under soil surface, soil water is normally only about 70cm under surface, distance from my ground rods and utility transformer ground rods is about 250 meters, electricity is one phase 220v 100a
My Question is :
Why Smart Meter MCB is tripped when ground fault occurs ?, Is That MCB at Smart Meter is Not Good ? or My Ground System Is Very Good and Resistance Between Ground Rods In My Home and Ground Rods In That Utility Company Connected At Transformer Neutral Is So Small ?
 

LowQCab

Joined Nov 6, 2012
1,096
I am certainly not familiar with the Smart-Meters used in China,
and I am guessing that MCB means "Main-Circuit-Breaker".

It is very possible that your "Smart-Meter" has a built-in Ground-Fault Function,
so that ANY VERY SMALL CURRENT that goes DIRECTLY to Ground will "Trip" the Breaker if the
Current does not return to the Meter on the "Neutral" Wire.

I am assuming that You have a "Hot" wire, and a "Neutral" wire, and a "Ground" wire coming
from your Meter.
A "Ground-Fault-Circuit-Interrupter" will "Trip" if
the Current flowing on the "Hot" and "Neutral" are not "PERFECTLY-EQUAL" to each other.

If a very slight Current flows from the "Hot" to ANY Ground,
which means that it is bypassing the "Neutral" wire,
and going straight to "Ground".

I think your "MCB" is a GFCI Circuit-Breaker.
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Yaakov

Joined Jan 27, 2019
3,492
I am certainly not familiar with the Smart-Meters used in China,
and I am guessing that MCB means "Main-Circuit-Breaker".
In this context MCB is for Magnetic Circuit Breaker which the TS is distinguishing from a GFCI. While it's true what he is taking for an MCB could include GFCI functionality, it would almost certainly include a test button which would reveal that.

It's a bit of a mystery, though, since no matter how good his ground is it is unlikely it could draw 100A without that being obvious from other things like sounds, smells, arcs, or melting of something. I surmise the ground fault is happening on a branch circuit so that would mean the branch had to handle the 100A for long enough to trip the MCB.

I like the idea it is a "secret" GFCI more than that it is actually tripping a 100A breaker...
 

LowQCab

Joined Nov 6, 2012
1,096
A "test" Button on a 100A Breaker seems a bit unlikely,
but on simple Rural Mains-Supplied Homes or Farms,
where power may be run in wet, outdoor situations,
it may make the difference between someone getting killed, or not.
220-Volts to Ground is SERIOUSLY DANGEROUS.
So there may be some sort of minimum manufacturing Code-Requirements that mandate
at least minimal human-life-protection must be "built-in" by default.

And it's cheaper to make the Breaker with no "test" Button.

And, no "test" Button may result in fewer "Nuisance" Service-Calls to simply re-set a Breaker,
that an Eight-Year-Old-Kid pushed as a prank.

By the way, very nice Ground-Rod installation,
a ~9-foot long Rod buried below the Water-Line.

And that brings up an interesting question ...........
Do they run a Ground or Neutral-Conductor between the Transformer and "Point-of-Use" ?????
It's possible that they only provide a single "Hot" Conductor,
and YOU have to supply your own Grounding-System.
This might sound crude, but it will work just fine with a good Grounding-Rod,
and it would save ~50% to ~66% on Wire costs for the Electrical-Provider.
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Thread Starter

meowsoft

Joined Feb 27, 2021
462
In this context MCB is for Magnetic Circuit Breaker which the TS is distinguishing from a GFCI. While it's true what he is taking for an MCB could include GFCI functionality, it would almost certainly include a test button which would reveal that.

It's a bit of a mystery, though, since no matter how good his ground is it is unlikely it could draw 100A without that being obvious from other things like sounds, smells, arcs, or melting of something. I surmise the ground fault is happening on a branch circuit so that would mean the branch had to handle the 100A for long enough to trip the MCB.

I like the idea it is a "secret" GFCI more than that it is actually tripping a 100A breaker...
There is no secret GFCI... China Standard is Not Same With Western Standard... MCB Is Miniature Circuit Breaker... There Is No Mandatory RCCB device or equivalent and Surge Protection Devices or Equivalent... I very know about that because I was contributed in smart meter manufacturing process
 

Thread Starter

meowsoft

Joined Feb 27, 2021
462
A "test" Button on a 100A Breaker seems a bit unlikely,
but on simple Rural Mains-Supplied Homes or Farms,
where power may be run in wet, outdoor situations,
it may make the difference between someone getting killed, or not.
220-Volts to Ground is SERIOUSLY DANGEROUS.
So there may be some sort of minimum manufacturing Code-Requirements that mandate
at least minimal human-life-protection must be "built-in" by default.

And it's cheaper to make the Breaker with no "test" Button.

And, no "test" Button may result in fewer "Nuisance" Service-Calls to simply re-set a Breaker,
that an Eight-Year-Old-Kid pushed as a prank.

By the way, very nice Ground-Rod installation,
a ~9-foot long Rod buried below the Water-Line.

And that brings up an interesting question ...........
Do they run a Ground or Neutral-Conductor between the Transformer and "Point-of-Use" ?????
It's possible that they only provide a single "Hot" Conductor,
and YOU have to supply your own Grounding-System.
This might sound crude, but it will work just fine with a good Grounding-Rod,
and it would save ~50% to ~66% on Wire costs for the Electrical-Provider.
.
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Yes... That is 80cm under water line, and soil water line isn't deep in my area just about 70cm under soil surface
My Utility Provides Only Neutral and Phase wire, Neutral Wire Is Connected To Substation, Earth-Grounded At Substation and of course in medium voltage to low voltage transformer near my house
No something like common ground wire from utility... just neutral connected at transformer and grounded
 

Thread Starter

meowsoft

Joined Feb 27, 2021
462
My question is just only bad ground rods... MCB is not tripping and arching in phase wire connected to ground rods, but if it is very good ground rods MCB is tripping... that's interesting for me... why resistance between ground at my home and utility's transformer is so small... and distance is near 300 meters, is that because the soil surface is very moistly nor water level is very shallow from soil surface (~70cm at rainy season, ~90cm at another season) ?
 

Thread Starter

meowsoft

Joined Feb 27, 2021
462
I am certainly not familiar with the Smart-Meters used in China,
and I am guessing that MCB means "Main-Circuit-Breaker".

It is very possible that your "Smart-Meter" has a built-in Ground-Fault Function,
so that ANY VERY SMALL CURRENT that goes DIRECTLY to Ground will "Trip" the Breaker if the
Current does not return to the Meter on the "Neutral" Wire.

I am assuming that You have a "Hot" wire, and a "Neutral" wire, and a "Ground" wire coming
from your Meter.
A "Ground-Fault-Circuit-Interrupter" will "Trip" if
the Current flowing on the "Hot" and "Neutral" are not "PERFECTLY-EQUAL" to each other.

If a very slight Current flows from the "Hot" to ANY Ground,
which means that it is bypassing the "Neutral" wire,
and going straight to "Ground".

I think your "MCB" is a GFCI Circuit-Breaker.
.
.
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Absolutely smart meter isn't have ground fault detection function... I was worked in smart meter manufacturing... and know all technology behind that... even if there is any very seriously ground-fault (about 1000mA) smart meter is detected as tampering not tripping MCB... and of course that function purpose isn't for ground-fault detection but electricity theft detection... you can death if ground-fault is reach over 30mA and this is 1000mA... so there is no ground-fault interrupter anywhere... MCB Manufacture is Schneider
 

Thread Starter

meowsoft

Joined Feb 27, 2021
462
Absolutely smart meter isn't have ground fault detection function... I was worked in smart meter manufacturing... and know all technology behind that... even if there is any very seriously ground-fault (about 1000mA) smart meter is detected as tampering not tripping MCB... and of course that function purpose isn't for ground-fault detection but electricity theft detection... you can death if ground-fault is reach over 30mA and this is 1000mA... so there is no ground-fault interrupter anywhere... MCB Manufacture is Schneider
One more... My ground rods isn't event connected to smart meter ground rods..., is fully separated and doesn't have any connection between smart meter ground and my common ground...
 

Thread Starter

meowsoft

Joined Feb 27, 2021
462
And also that 1000mA (one thousand mili-amp / one amp) current leakage detector function is protect transformer from over capacity... in China we have contracted electric capacity (1a, 2a, 4a, 6a, 10a, 16a, 20a, 25a, 50a, 63a, 80a, 100a, 3x 6a, 3x10a, until 3x 300a, more than 3x 300a have customer own sub station, no 220v/380v available but 11kV or 20kV)... some people illegally change MCB inside smart meter but you can get penalty for this... also some people replace neutral with that own ground wire connected to ground rods to bypass that MCB capacity (MCB Over-current function) and that is very dangerous and can make transformer over capacity, this is why there is any 1000mA current leakage detection function
Note : if you increase contract size legally you also pay fee for that, and that's not cheap for some people

Smart meter internals fraud function in China :
- Detect if neutral and phase wire is swapped (also swapped in 3 phase wire, e
- Detect if neutral and phase wire is not equal
- Detect if smart meter ground wire is not work nor cutted
- Detect if neutral is connected with ground wire at smart meter
- Detect if smart meter case is open
- Detect if AMR (automatic meter reading) is removed
- Detect if there is any current leakage over 1000mA
If one of that function detection is triggered meter is in tampering state, and electricity is cutted from relay NOT MCB, for resetting tampering state clear tamper code is needed and only utility company have that code
 

LowQCab

Joined Nov 6, 2012
1,096
OK,
lots of good information,
so we are not guessing quite so much.

But I still don't know exactly what problem you are having,
or exactly what Your question is.

All I know is that your MCB is tripping.

Why do you think this is happening ?

Also, very interesting,
Schneider is an American Company,
they are usually called "Square-D" in America.
( I was an Electrician for ~20-years)

The picture shows what I understand about your problem so far.

Definitions .......
a "Neutral- Wire" is a Current carrying Ground Wire, and "may" have some small Voltage higher than Ground.
A "Ground-Wire" does not normally carry Current, it is for Safety Only.
Meter may "disconnect" if a monitored condition Fails...... Requires Special Code to Re-Set.
MCB- Main Circuit Breaker, "Not-Smart", Trips only with more than >100A.
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Chinese AC Power Problem .png
 
Last edited:

LowQCab

Joined Nov 6, 2012
1,096
I don't know what the problem is.
The Picture is only what I understand so far.
The Picture may not be accurate.
I am hoping that the Picture will make it easier to describe the problem.
.

Your MCB Tripped.

What device was connected to the MCB ?

Was anything conducting Current from MCB directly to Ground or a Ground-Rod ?
( bypassing the normal return-path through the Neutral-Conductor ) ?

You mentioned something about the Ground-Rods being a long distance apart .........,
why is this fact significant ?

Was any Equipment or Wiring damaged from Electrical-Arcing when the MCB Tripped ?

Why do you think that the MCB should NOT have tripped ?
.
.
.
 

Thread Starter

meowsoft

Joined Feb 27, 2021
462
I don't know what the problem is.
The Picture is only what I understand so far.
The Picture may not be accurate.
I am hoping that the Picture will make it easier to describe the problem.
.

Your MCB Tripped.

What device was connected to the MCB ?

Was anything conducting Current from MCB directly to Ground or a Ground-Rod ?
( bypassing the normal return-path through the Neutral-Conductor ) ?

You mentioned something about the Ground-Rods being a long distance apart .........,
why is this fact significant ?

Was any Equipment or Wiring damaged from Electrical-Arcing when the MCB Tripped ?

Why do you think that the MCB should NOT have tripped ?
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PLEASE READ MY EDITED PICTURE
 

Thread Starter

meowsoft

Joined Feb 27, 2021
462
MY PROBLEM ISN'T NORMAL PROBELM IS VERY COMPLEX
Question :
1. It Is Dangerous To Make Very Good Ground Rods Than Power Substation ?, 20 Meters Copper Rods 2" 5 Meters Under Soil Surface ?, I Have very enough money to do this..., I Also have small substation in my house, that feed by utility's 20.000v, My Home is for scientific... so don't assume is normal home, (100a in China is of course normally for small industry nor very very big home), also my home is former small factory
2. Can Lightning or Current Leakage In ALL Substation Load (Utility Substation) go through my ground because my ground system is far better than utility's own ground system ?, Because My Ground System Is Connected To Utility's Company Through Electrical Appliance... and Also Connected To 20kV feeder (this feeder have ground wire)..., let's say factory in near my house is have great current leakage (same 20kV system), can that current leakage goes through my ground system too ?
Note : I have two electricity Supply From Utility's One Is 100a 220v, and One Is 10a 20.000v/20kV go to my private substation (20kV/0.4kV 500kVA Transformer, Load Break Switch, Fuse Cut Out, and Also Medium and Low Voltage Switch Gear), 20kV is Wire is R-S-T and Ground/PE this is not neutral, 220v is Phase and Neutral
 

Thread Starter

meowsoft

Joined Feb 27, 2021
462
More Questuion :
SO... YOU KNOW DIRECT PHASE - NEUTRAL CONNECTION IS SHORT CIRCUIT, I CONNECT PHASE - GROUND WHY AND THIS IS ALSO SHORT CIRCUIT, WHY RESISTANCE BETWEEN MY GROUND AND UTILITY GROUND IS SO SMALL ?
Normally PHASE - GROUND is ground fault, In MY VERY GOOD GROUND SYSTEM is treated as short circuit, WHY THIS THINGS HAPPEN ?
Normally I Can Get My House Burnt, Without RCCD or Equivalent Protection... and yes... of course this is for scientific... wildfire isn't a problem... every risk is calculated carefully, another house in newspaper got wildfire because ground fault... WHY I AM NOT HAVE SAME THING HAPPEN ?
ALSO DON'T ASSUME THIS IS NORMAL HOUSE, VERY CAREFULLY READ MY POST, MY HOUSE IS FORMER FACTORY, AND ALSO HAVE MICRO SUBSTATION WITH 20.000v/20kV Feeder
 

Thread Starter

meowsoft

Joined Feb 27, 2021
462
I don't know what the problem is.
The Picture is only what I understand so far.
The Picture may not be accurate.
I am hoping that the Picture will make it easier to describe the problem.
.

Your MCB Tripped.

What device was connected to the MCB ?

Was anything conducting Current from MCB directly to Ground or a Ground-Rod ?
( bypassing the normal return-path through the Neutral-Conductor ) ?

You mentioned something about the Ground-Rods being a long distance apart .........,
why is this fact significant ?

Was any Equipment or Wiring damaged from Electrical-Arcing when the MCB Tripped ?

Why do you think that the MCB should NOT have tripped ?
.
.
.
Of COURSE MCB TRIP IS PROBLEM... NOT GET FIRE IS PROBLEM... NORMALLY YOU CAN BURN'T YOUR HOUSE WITH GROUND FAULT and NO MCB is TRIPPING with STANDARD GROUND (not very very good ground system outside CN standards)... and yes electrical standard in CN is not good
 

djsfantasi

Joined Apr 11, 2010
7,827
Of COURSE MCB TRIP IS PROBLEM... NOT GET FIRE IS PROBLEM... NORMALLY YOU CAN BURN'T YOUR HOUSE WITH GROUND FAULT and NO MCB is TRIPPING with STANDARD GROUND (not very very good ground system outside CN standards)... and yes electrical standard in CN is not good
ok, I’m done with this thread. When a TS resorts to all caps, it usually means they are frustrated because they can’t understand the responses. So they take it out on members. Yep, that’s when I stop following a thread.
 

LowQCab

Joined Nov 6, 2012
1,096
Please pardon my corrections to your English Grammar.
I made corrections so that i can understand your questions completely.
Chinese AC Power Problem -2a- .png


Question #1)
Why is Hot, (Phase 1), showing a DIRECT SHORT CIRCUIT to Ground ?
The "short answer" is because Ground and Neutral are essentially the exact same thing.

The "long answer",
ALL THE WAY from the Power Generating Station, to your Home .........
At every possible opportunity, (every Transformer, every Power-Pole, every Junction of Wires ),
the Neutral-Conductor is connected to a Grounding-Rod,
there are 100's or even 1000's of points where
the Neutral Conductor is Grounded via a Grounding-Rod.
GROUNDING RODS EVERYWHERE !!!
The Neutral Wire is attached to ALL OF THEM !!!

Now .......,
Here is the "trick" to this question.

You have 2-Jobs for the Neutral / Ground Wires,
that is the ONLY reason that there are 2-different Names for Wires that are connected together.

The "Neutral" Wire is designed to carry Current that is RETURNING TO GROUND.

The "Ground" wire should NEVER carry Current.

When a Wire is carrying Current,
it MUST HAVE a different Voltage on each end of the Wire.

So, lets make an example ........
Imagine that you have an Electrical Machine with a Metal Cover.
You "should have" 3-Wires going to the Machine,

1) Hot Wire,
this Wire has 220 Volts "above-ground" or,
"relative to ground" or,
"measured to ground",or
"to-ground",
( all these descriptions mean the same thing ).

2) Neutral Wire,
this Wire has "almost" "0-Volts" to ground.
The reason that this Wire is not the same as the Ground wire,
is because when a Wire has Current Flowing in it,
it has a higher voltage on one-end.
A Wire ALWAYS has a "Resistance",
which creates a "Voltage-Drop", or
a difference in Voltage from one end to the other end.
So,
even though the Neutral is Connected to Ground on one end, ( at the MCB ),
DOES NOT MEAN that the Voltage is at "Ground-Potential" at the other end.
The Voltage on the Neutral Wire will be "above-ground" at the Machine.
( only when the Machine is "on" and causing Current to flow on the Neutral Wire ).

3) Ground Wire,
The Ground Wire is the same as the Neutral Wire, "with the exception of" the fact that
NO CURRENT FLOWS ON THE GROUND WIRE,
so it is always EXACTLY at "0"-Volts above Ground.
The Ground Wire is connected to the Metal-Cover of the Machine.
The ONLY PURPOSE of the Ground Wire is "Personnel-Protection".

Now, lets imagine that the Neutral wire is attached to the Metal Cover of the Machine.
"You" are bare-footed, (no shoes on your feet), and
you are standing on a damp concrete floor, ( which can conduct Electricity very well ).

If you touch the Metal Cover of the Machine, you could receive an "Electrical-Shock"
from your Hand, to your Feet,
because the Metal Cover of the Machine is "Above-Ground".
Maybe the Voltage of the Neutral Wire is "only" ~1 or ~2 Volts,
"MAYBE" this is not a "Dangerous" Voltage level.

But,
What would happen if the Machine draws HEAVY CURRENT, and
the Wires are "too small" for that level of Current Flow ???????
Now you would have a substantial "Voltage-Drop" on the Wires,
meaning that,
the Neutral Wire is now (maybe) ~10-Volts "Above-Ground".
~10-Volts is enough to shock you, ( but it will probably not kill you ).

But a proper Ground Wire, with "0" Current flowing on it,
will still remain at "0" Volts Above-Ground, at all times.

So, the question is ........

Do you want the "Neutral Wire" attached to the Metal Cover of the Machine,
or,
Do you want the "Ground Wire" attached to the Metal Cover of the Machine ???????
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Chinese AC Power Problem Voltage Drop 1 .png
 
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