Circuit Breaker teardown and defective Siemens latching mechanism

[kwired]

Ok. Thanks for the info. Need to convince the neighbors. Lol.

Well. I'm presently studying about arc flash. How many current in a wire before it can become explosive enough to injure the electrician?

https://www.youtube.com/watch?v=6hpE5LYj-CY

Once I saw an electrician trying to connect a breaker live. Although there is no direct connection between two terminals. There are carbon sooths, and this created a small arc flash enough to injure him. After that. I won't even go near an electrician when he fixed stuff. And also staying from the electronic or electrical engineering field as it's very dangerous field.

In the Philippines where electricians don't have to worry about neutral and grounding, but just able to connect the red and black wires without even polarity. Many of them are doing it live (only skill they can boost that cut them above ordinary folks). I know this is very dangerous. Many of them don't even know what is arc flash.

I want to share them this so they be more careful. In a basic home panel. What usually is the current before the arc flash can occur similar or even half the video (above) intensity?

And if AFCI are installed. Can it totally prevent it or just diminish the intensity (by how many percentage)?

"Incident energy" is what determines how dangerous the arc flash is. Not every incident will be the same.

Safety policies will calculate a maximum expected incident energy level to determine what PPE is necessary to work on a particular piece of equipment. A lot of times you aren't permitted to work live but must still don protection to take voltage readings to ensure it is dead before working on it.

Said incident energy level calculations take the available fault current as well as the trip curve of overcurrent devices into consideration, but it is still a little more complex than just those two items, high current for short time can still release less overall energy than a lower current for longer time.

 

[tersh]

Oh, this is easy! UL did a residential aging report, and the majority of the breakers that failed to trip where outdoors (in a rain proof enclosure)- I can only imagine here where they are actually being rained on.


I do not know the internals, but it would not shock me if they have all seized up considering the above is a code violation. Breakers must be protected from water.

If the rain can get inside the breakers. Then if the springs are rusted. There is the possibility when you turn it to off position, it won't return to on because the springs and rusty latches would no longer work, isn't it?

 

[LarryFine]

I've never seen anything this ridiculously bad. :jawdrop:

 

[tersh]

I've never seen anything this ridiculously bad. :jawdrop:

It's typical Philippines service entrance. This is outside our townhouse when we bought it second hand.

The panel cover gave way after it was rusted. The 4 neighbors refuse to cooperate to have it repaired. This is because inside each house there is a separate one like it before the main panel. So it can be treated as just a conductor with the internal parts like springs and thermal and magnetic strips no longer working.

I need to master computations of arc flash so in case it rains and the terminals shorted. I want to estimate if it can create self sustaining plasma that can grow large in size as it engulf the panels or area.


What is the best book or reference about arc flash and example of actual computations?

 

[kwired]

It's typical Philippines service entrance. This is outside our townhouse when we bought it second hand.

The panel cover gave way after it was rusted. The 4 neighbors refuse to cooperate to have it repaired. This is because inside each house there is a separate one like it before the main panel. So it can be treated as just a conductor with the internal parts like springs and thermal and magnetic strips no longer working.

I need to master computations of arc flash so in case it rains and the terminals shorted. I want to estimate if it can create self sustaining plasma that can grow large in size as it engulf the panels or area.


What is the best book or reference about arc flash and example of actual computations?

How spectacular of a flash can occur is probably mostly dependent on what contaminants can accumulate that won't burn until something sets them off, most the time a little moisture presence will begin to conduct and vaporize itself until it can't conduct, and cycle gets repeated. component failure resulting in lost power through the device is more likely to happen first - at which point user will have an interest in doing something to restore power again, though it may be just to replace failed breaker unfortunately in your case with one that will be subjected to same conditions and probably will eventually fail again. I have bigger concern over potential shock hazards with this installation than with potential arc flash being on any severe level - unless maybe the source transformer is only 5 feet of supply conductor away, but from other posts you have made sounds like it is probably at the top of a pole.

 

[zog]

What is the best book or reference about arc flash and example of actual computations?

IMO this is one of the best books on the subject

https://brainfiller.com/product/complete-guide-to-arc-flash-hazard-calculation-studies/

 

[mbrooke]

If the rain can get inside the breakers. Then if the springs are rusted. There is the possibility when you turn it to off position, it won't return to on because the springs and rusty latches would no longer work, isn't it?

Its possible.

 

[kwired]

Can't speak for the breakers in your image, but most will have openings for pressure relief should the device have to open under high current conditions. Those openings will let not only moisture but insects, dirt, etc. inside and those things also cause trouble with operation of internal parts.

 

[tersh]

Its possible.

mbrooke. Why are some breakers so big and some so small (like the European breakers) yet they have same rating say 125A. For example, the following GE is so big.

Compared it to other very small compact breakers 1/3 its size. Do you think the thermal strip is same size for both since you have seen the internal components of so many breakers? Which do you prefer, big or small and why?

 

[mbrooke]

mbrooke. Why are some breakers so big and some so small (like the European breakers) yet they have same rating say 125A. For example, the following GE is so big.

Compared it to other very small compact breakers 1/3 its size. Do you think the thermal strip is same size for both since you have seen the internal components of so many breakers? Which do you prefer, big or small and why?

Look into "amp frame"


Every amp trip has a maximum frame size, for example the highest you can can get for a 1 inch style 2 pole plug in breaker is 125 amps, that is unless you want to take up 4 spaces and a bit of gutter space its 200amps.

Higher current ratings will have larger sizes, but you can also get smaller ratings in the same package to fit the same space.


Ie, many years ago the number of spaces in load centers was limited, and a 125 amps 42 space panel was not available to my knowledge- but if you needed the space and 125amps was your service size, you could take a 200amp 42 space panel and swap the 200amp main with the exact 125 amp you pictured. It would fit will meeting code. Another common example is in switch-gear and panel boards where you have a location for a 400 amp frame, but need say a 20 amp lighting circuit.

 

[tersh]

Look into "amp frame"


Every amp trip has a maximum frame size, for example the highest you can can get for a 1 inch style 2 pole plug in breaker is 125 amps, that is unless you want to take up 4 spaces and a bit of gutter space its 200amps.

Higher current ratings will have larger sizes, but you can also get smaller ratings in the same package to fit the same space.


Ie, many years ago the number of spaces in load centers was limited, and a 125 amps 42 space panel was not available to my knowledge- but if you needed the space and 125amps was your service size, you could take a 200amp 42 space panel and swap the 200amp main with the exact 125 amp you pictured. It would fit will meeting code. Another common example is in switch-gear and panel boards where you have a location for a 400 amp frame, but need say a 20 amp lighting circuit.

How about the tiny Din Rail breakers used in 230v countries. What is the smallest 125A form factor? Do you think they all use solenoids instead of magnetic strip?

I guess in purely 230v countries. They only use din rail and no plug-in or bolt-on for residential use? In the Philippines. We have both plug-in and din rail for home use. Plug-in to take advantage of US breakers like GE. Din rail to take advantage of other brands of breakers.

In the US black and red 240v phase to phase. If you put a European Din rail 230v breakers. It can work? I know the 120v to neutral won't work in din rail which is mostly 230v.

 

[mbrooke]

How about the tiny Din Rail breakers used in 230v countries. What is the smallest 125A form factor? Do you think they all use solenoids instead of magnetic strip?

I think 125 is the max amp rating you can get in a typical 16 amp package.

The solenoid is the magnetic trip function.

I guess in purely 230v countries. They only use din rail and no plug-in or bolt-on for residential use? In the Philippines. We have both plug-in and din rail for home use. Plug-in to take advantage of US breakers like GE. Din rail to take advantage of other brands of breakers.

The world has 2 markets basically, or rather started off with two different designs and codes as created by two different super powers:


1. The US style of breakers and panel-boards with UL and NEC standards dictating the product, and wired to the NEC or a code based on the NEC (ie CEC is based on the NEC). The set standard is 120 volts line to ground, 60Hz. Much the same with utility systems, NESC and IEEE dictate most of it.


2. The European style of equipment, designed and standardized around European codes and safety standards. Latter this would give rise to the IEC set out to harmonize Germany, France and the United Kingdom. The set standard is 230 volts line to ground and 50Hz. Similar for utility systems, those countries developed their own independent standards, design, ect governing high voltage.


As time went on, these two different standards spread outside the borders; Canada, Mexico and the Islands took what their neighbors had. Brazil took the 60Hz Mexico had. Similarly Russia, India and the middle east took what Europe had, and it continued to spread downwards.


Areas occupied by the US that did not have power were built up on upon US standards, like Saudi Arabia and the Philippines. Places occupied by Europe took the European standard like Jamaica for example, British occupied territory even has BS1363 plug thousands of miles away. Also the reason why Japan has 50Hz on one side 60 on the other- those tasked with electrifying it built to the standard they grew up with.


Today however with both systems in place and a global economy with the desire to standardize you have both systems along with their variants clashing together.

The Philippines is a perfect example of this, its entirely based on US design but sees the cost savings and simplicity in wiring to 230 volts and using 230 volt equipment common to that part of the world. Jamaica is 50Hz, but uses 120 volt equipment despite often being incompatible because their closet trading partners are 120 volt.

In the US black and red 240v phase to phase. If you put a European Din rail 230v breakers. It can work? I know the 120v to neutral won't work in din rail which is mostly 230v.

It will certainly work- regular DIN IEC breakers do not care about voltage.

 

[tersh]

I think 125 is the max amp rating you can get in a typical 16 amp package.

The solenoid is the magnetic trip function.

Thanks a lot for the summary.
What do you mean by "16 amp package"?

Do you have samples of what the main panels (say 16 breaker panel) look like for those countries that use purely din rail breakers? Is it all horizontal? What is equivalent that look like the American plug-in panels (rectangular vertical)?

The world has 2 markets basically, or rather started off with two different designs and codes as created by two different super powers:


1. The US style of breakers and panel-boards with UL and NEC standards dictating the product, and wired to the NEC or a code based on the NEC (ie CEC is based on the NEC). The set standard is 120 volts line to ground, 60Hz. Much the same with utility systems, NESC and IEEE dictate most of it.


2. The European style of equipment, designed and standardized around European codes and safety standards. Latter this would give rise to the IEC set out to harmonize Germany, France and the United Kingdom. The set standard is 230 volts line to ground and 50Hz. Similar for utility systems, those countries developed their own independent standards, design, ect governing high voltage.


As time went on, these two different standards spread outside the borders; Canada, Mexico and the Islands took what their neighbors had. Brazil took the 60Hz Mexico had. Similarly Russia, India and the middle east took what Europe had, and it continued to spread downwards.


Areas occupied by the US that did not have power were built up on upon US standards, like Saudi Arabia and the Philippines. Places occupied by Europe took the European standard like Jamaica for example, British occupied territory even has BS1363 plug thousands of miles away. Also the reason why Japan has 50Hz on one side 60 on the other- those tasked with electrifying it built to the standard they grew up with.


Today however with both systems in place and a global economy with the desire to standardize you have both systems along with their variants clashing together.

The Philippines is a perfect example of this, its entirely based on US design but sees the cost savings and simplicity in wiring to 230 volts and using 230 volt equipment common to that part of the world. Jamaica is 50Hz, but uses 120 volt equipment despite often being incompatible because their closet trading partners are 120 volt.





It will certainly work- regular DIN IEC breakers do not care about voltage.

 

[mbrooke]

Thanks a lot for the summary.
What do you mean by "16 amp package"?

One of this physical size:

Do you have samples of what the main panels (say 16 breaker panel) look like for those countries that use purely din rail breakers? Is it all horizontal? What is equivalent that look like the American plug-in panels (rectangular vertical)?

Yes, here is a British Consumer unit:

One with RCBOs:

France:

 

[tersh]

mbrooke.. why are all the panels plastic? Can it contain any arcing or fires inside the panel or in the breakers? I saw in youtube many american metal panels with burning or fried breakers. Does it mean bus bar less din rail breakers are more resistant to arcing and fire?

Also is there 5mA RCD personal protection? How does it look like when integrated in the panels. I couldn't find one last year that was why I made the following choice.

I couldn't find any 5mA RCD with auto monitoring self-test. So settled with the state of the art Siemens 2-pole GFCI breakers 5mA with circuit based auto-monitoring Self-Test.

It is full house GFCI protection (even the lights were protected). The electrician with 2 supervising electrical engineers were currently making it as the main panel with subpanel feed of by one 60A GFCI breaker using AWG 6 wire.

It is 100% nuisance tripping free. It doesn't nuisance trip on refrigerators, water pik motors, airconditioners etc, where the 240v GFCI receptacles could nuisance trip on them consistently. Also GFCI receptacles can't protect 6000w bath heaters which need 30A breakers and air conditioners.

The great thing about full house GFCI protection is that it can detect wiring that has one live touching the concrete. We have detected 2 wiring that continuously tripped on the GFCI breakers at power on. It is wiring to the washing machine and wiring to the attic outlets. The former owner said the attic outlets have shorted before and some wires cut. But they still use the wires remaining. The GFCI is able to detect that the remaining wire has touched concrete already.

And the washing machine outlet were just added by electrician latter with cement filing up the hole. So full house GFCI protection is very important in third world countries especially since we don't have any EGC, GEC. ​

Well. Right now. Maybe the house is the only full house GFCI protected one in the country so far, lol.

Btw.. one of the engineers told me last week the panel above can cause arc flash, hence must be covered at all times in between works. This was the main reason I inquired about arc flash lately. I don't inquire things I dreamt the night before as one guy commented. Lol. Since I'm also an engineer. Then I really need to the bottom of this arc flash thing so I can inform the engineer about source incident energy and arc flash.

And oh. The feeders diverge immediately after the exit in different directions so it doesn't make the 24 inches length that should cause 50% deratement. Besides the autotransformer which powers the 120v Siemens GFCI circuitry. What other violations of NEC?

This setup can also be used by all other 240v countries (where it's 240v to 0v neutral instead of centertapped neutral)?

 

[Adamjamma]

Britain allowed plastic breaker panel boxes until a study found they could catch fire supposedly... so they now require metal boxes but... I would prefer the plastic boxes for the installs I do...
Amendment three jokes..lol just another excuse to make a certain group of people extra money in required training and courses for no real return.

 

[tersh]

IEC breakers tend to have solenoids to help lower the magnetic trip threshold. At 230 volt line to ground its a good idea to have a quick disconnect time when a fault occurs.

In terms of reliability and lifetime. Which in your research lasts longer,. the din rail IEC MCB (Miniaturized Circuit Breakers) or the North American Breakers (Plug in, Bolt On, Molded Case?

Could the miniaturized breakers be more prone to heat since there is less space inside?

In the din rail IEC MCB, the coil thing is the solenoid. While in the US breakers, the electromagnet is simply this:

Do you have internal diagram of the electromagnet strip? Does it have coil inside it?

Which can act faster and more reliable?

In Europe. What is the most expensive and highest quality din rail IEC MCB (Miniaturized Circuit Breakers)? In US. It's Square D, Siemens, General Electric which are the plug in leaders for example.

Thanks.

 

[mbrooke]

mbrooke.. why are all the panels plastic? Can it contain any arcing or fires inside the panel or in the breakers?

Honestly I do not know why they are plastic- but as of late in the UK metal ones have become mandatory for new installations or consumer unit changes. Here is an example of one:




https://www.youtube.com/watch?v=C3ZU8QlSnVs

I saw in youtube many american metal panels with burning or fried breakers. Does it mean bus bar less din rail breakers are more resistant to arcing and fire?

Well, if you take a look at this site, its clear DIN rail breakers are just as bad:

http://www.kontrollbuero.ch/fotogalerie/fotogalerie.htm

Also is there 5mA RCD personal protection? How does it look like when integrated in the panels. I couldn't find one last year that was why I made the following choice.

In the UK its usually 30ma for panels, sometimes less for RCD sockets. This one though is 30ma:

I couldn't find any 5mA RCD with auto monitoring self-test. So settled with the state of the art Siemens 2-pole GFCI breakers 5mA with circuit based auto-monitoring Self-Test.

It is full house GFCI protection (even the lights were protected). The electrician with 2 supervising electrical engineers were currently making it as the main panel with subpanel feed of by one 60A GFCI breaker using AWG 6 wire.

Sounds good to me, and wise to do with no EGC.

It is 100% nuisance tripping free. It doesn't nuisance trip on refrigerators, water pik motors, airconditioners etc, where the 240v GFCI receptacles could nuisance trip on them consistently. Also GFCI receptacles can't protect 6000w bath heaters which need 30A breakers and air conditioners.

Question- what wire size to general sockets is being used? What is it protected at?

The great thing about full house GFCI protection is that it can detect wiring that has one live touching the concrete. We have detected 2 wiring that continuously tripped on the GFCI breakers at power on. It is wiring to the washing machine and wiring to the attic outlets. The former owner said the attic outlets have shorted before and some wires cut. But they still use the wires remaining. The GFCI is able to detect that the remaining wire has touched concrete already.

And the washing machine outlet were just added by electrician latter with cement filing up the hole. So full house GFCI protection is very important in third world countries especially since we don't have any EGC, GEC. ​

Fully agree- if you do not have an EGC you need RCDs/GFCIs. It scenarios like yours which show just how a wiring system that appears fine could have future fires and electrocutions just sitting there.

Well. Right now. Maybe the house is the only full house GFCI protected one in the country so far, lol.

Btw.. one of the engineers told me last week the panel above can cause arc flash, hence must be covered at all times in between works. This was the main reason I inquired about arc flash lately. I don't inquire things I dreamt the night before as one guy commented. Lol. Since I'm also an engineer. Then I really need to the bottom of this arc flash thing so I can inform the engineer about source incident energy and arc flash.

And oh. The feeders diverge immediately after the exit in different directions so it doesn't make the 24 inches length that should cause 50% deratement. Besides the autotransformer which powers the 120v Siemens GFCI circuitry. What other violations of NEC?

There are several NEC violations, but in this case given what you have to work with it appears resaonbaly safe.

This setup can also be used by all other 240v countries (where it's 240v to 0v neutral instead of centertapped neutral)?

It can be- but those siemens AFCI breakers would not work.


Given what the Phillipines has to work with, I think the country should consider switching to an IEC based code- for example TT earth is legal in such codes, and would help with the lack of neutrals at the service.

 

[mbrooke]

In terms of reliability and lifetime. Which in your research lasts longer,. the din rail IEC MCB (Miniaturized Circuit Breakers) or the North American Breakers (Plug in, Bolt On, Molded Case?

Well, thats hard to say- but I do know that breakers installed outdoors or in a wet basement, even in a proper enclosures- are many times more likely to seize up.

Could the miniaturized breakers be more prone to heat since there is less space inside?

All thermal magnetic breakers are effected by heat to some degree, which is why the NEC has the 80% rule for loads running longer then 3 hours or specific equipment.


However, in residential the load is so cyclic that even if you sized circuits and breakers at 100% I doubt it would be an issue, even with electric heat. In the IEC world residential and light commercial is sized at 100%, even with loads running longer then 3 hours and there is no issue.

Now if dealing with a factory or a huge panel with every circuit loaded to the max 24/7 designing to 80% might be a good idea.


Now, if there is one design the may be susceptible in a well loaded panel I give you these beasties to the right

A.k.a GE THQP and tandem breakers.

In the din rail IEC MCB, the coil thing is the solenoid. While in the US breakers, the electromagnet is simply this:

[/QUOTE]

That is the electromagnet, at least it pretends to FPE breakers. FPE breakers have been tested an its been determined that strip does absolutely nothing. Fortunately in modern US breakers the story is different, the magnetic trip works and clears high current dead shorts very fast.

Do you have internal diagram of the electromagnet strip? Does it have coil inside it?

No coil, its a movable piece that attracts to another piece carrying current.

Which can act faster and more reliable?

I'd say the US design is slightly more reliable.

Both are equally fast when current exceeds the trip threshold. I'd argue the US design might be a hair faster because it directly unlatches the breaker where as in the IEC the solenoid pin has to strike a level and move a few more parts to unlatch.


However, the IEC design allows the breaker to have a lower magnetic pickup when needed. B type MCBs have a magnetic pickup of around 3-5x, while US breakers are around 10x.

In Europe. What is the most expensive and highest quality din rail IEC MCB (Miniaturized Circuit Breakers)? In US. It's Square D, Siemens, General Electric which are the plug in leaders for example.

Thanks.

In Europe I'm not 100% sure- but certainly look for big brands like ABB and Siemens. Avoid off label or mystery brands- and look for a certificate to make sure its not counterfeit. You might guess this "slow blow" marvel:

In the US Square D in my opinion is the best, both their QO and Homeline brands are great.

 

[tersh]

Honestly I do not know why they are plastic- but as of late in the UK metal ones have become mandatory for new installations or consumer unit changes. Here is an example of one:




https://www.youtube.com/watch?v=C3ZU8QlSnVs





Well, if you take a look at this site, its clear DIN rail breakers are just as bad:

http://www.kontrollbuero.ch/fotogalerie/fotogalerie.htm




In the UK its usually 30ma for panels, sometimes less for RCD sockets. This one though is 30ma:

Sounds good to me, and wise to do with no EGC.



Question- what wire size to general sockets is being used? What is it protected at?

The 30A GFCI breakers use AWG 10 wire to the sockets. The 60A GFCI breakers use AWG 6 to the subpanel. It is the main panel. The electrician and even some engineers didn't suggest 20 space Siemens load center last year as we were not even sure it could work, so settled for the 12 space (6 breakers only). I mean, what if it would nuisance trip on the fridge, air conditioning units, others. Fortunately it has zero nuisance tripping, unlike the GFCI receptacles which can trip on the fridge twice a day for example.

However, the IEC design allows the breaker to have a lower magnetic pickup when needed. B type MCBs have a magnetic pickup of around 3-5x, while US breakers are around 10x.

US breakers can trip when overcurrent reaches 20X. What brands or categories are 20X and which is 10X? And did you mean in the B type MCBs. It can trip just 5x overcurrent? Then it is better. For main breaker (or backup disconnect) in residential, do you think B type MCBs is better? or would it nuisance trip on the fridge, washing machine, water pump, etc.? What is the minimum magnetic pickup for residential?​

Fully agree- if you do not have an EGC you need RCDs/GFCIs. It scenarios like yours which show just how a wiring system that appears fine could have future fires and electrocutions just sitting there.





There are several NEC violations, but in this case given what you have to work with it appears resaonbaly safe.





It can be- but those siemens AFCI breakers would not work.


Given what the Phillipines has to work with, I think the country should consider switching to an IEC based code- for example TT earth is legal in such codes, and would help with the lack of neutrals at the service.