Circuit Breaker teardown and defective Siemens latching mechanism

[tersh]

So you break both legs to the lights?





No wrath, its temporary as you are in the process of having your panel changed.




In Europe DIN rail breakers are usually horizontally installed going left to right...

mbrooke, another major reason for the delay was because the electrician had to drill new holes to put the rails. But mere drilling could deposit metals to the panel which could be arc flash risk. Second, how do you drill hole to put the screw tux when the metal chassis was already installed on the wall:

The above was usually installed with the plastic tux put inside the concrete, then the metal chassis put over it and the small hole drilled in the chassis to put the screw. But with the chassis already in place, It is not the right screw, so how do you secure or put the rails to the chassis?

Third problem was the electrician or contractor I knew doesn't have battery operated drilling machine and I don't have either. So when we shut off the power to the building. We don't have power to operate a normal ac plug in drilling machine.

 

[mbrooke]

For decades. I have never seen any electrician or domestic helpers or even owners turn off the circuit breaker just to change light bulb. The reason is because the screw shell is hidden inside with porcelain or plastic casing outside (see picture below of typical socket). So when you hold the light bulb at the lower half end. There is just no way to touch the screw shell unless the person is blind (but then he could still feel where the lower half of the light bulb is)

I see a sliver of the screw shell. What if I touched it while unscrewing the bulb?

 

[mbrooke]

mbrooke, another major reason for the delay was because the electrician had to drill new holes to put the rails. But mere drilling could deposit metals to the panel which could be arc flash risk. Second, how do you drill hole to put the screw tux when the metal chassis was already installed on the wall:

The above was usually installed with the plastic tux put inside the concrete, then the metal chassis put over it and the small hole drilled in the chassis to put the screw. But with the chassis already in place, It is not the right screw, so how do you secure or put the rails to the chassis?

Third problem was the electrician or contractor I knew doesn't have battery operated drilling machine and I don't have either. So when we shut off the power to the building. We don't have power to operate a normal ac plug in drilling machine.

Not sure, I've never put DIN in a US panel can. Though someone with sheet metal experience would know. Maybe self tapping screws?

https://www.homedepot.com/b/Hardware-Fasteners-Screws-Self-Drilling-Screws/N-5yc1vZc2d6

 

[romex jockey]

Good grief Tersh.....

I hate to say it, but modifications to listed equipment would normaly be required to go through the prevelant bureaucratic channels here

~RJ~

 

[tersh]

Good grief Tersh.....

I hate to say it, but modifications to listed equipment would normaly be required to go through the prevelant bureaucratic channels here

~RJ~

It's not even listed equipment. I mean, all our plug in panels are locally made with thin bus bar stubs to save metal. We never have US made original GE panel. I have never seen one before in my life. Therefore all our panels were not even listed to take the GE breakers or any brands.

 

[romex jockey]

I guess we live sheltered lives here Tersh, it does not occur to many that the circumstances you exist in are probably a given for many on this rock.

That said electrical theory does not change for any of us anywhere, so please keep asking ,even provoking , it's good for us that want to learn to be a wee bit uncomfortable .....~RJ~

 

[mbrooke]

I guess we live sheltered lives here Tersh, it does not occur to many that the circumstances you exist in are probably a given for many on this rock.

That said electrical theory does not change for any of us anywhere, so please keep asking ,even provoking , it's good for us that want to learn to be a wee bit uncomfortable .....~RJ~

Common reason for DIN being so popular, they let you make a busbar out of scrap wire:

 

[tersh]

I guess we live sheltered lives here Tersh, it does not occur to many that the circumstances you exist in are probably a given for many on this rock.

That said electrical theory does not change for any of us anywhere, so please keep asking ,even provoking , it's good for us that want to learn to be a wee bit uncomfortable .....~RJ~

Our panels were actually made by private companies or even the electrical stores. For example see this:

https://alliedcormultitech.com.ph/

It is a private company and fabricate many of our panels. They built the plug in and bolt on panels. Not only that but the bus bar as well. They estimate the thickness based on what they think is ok. That was why I was asking what is the exact thickness of original US GE Panel bus bar stubs using calipers. So if i'd find out our locally manufactured versions are significantly thinner. Then I'd surely have the present panel replaced asap. But if the thickness are close. Then it may be delayed for longer while awaiting expert electrical contractor.

I asked them about rail din panels. They said it was just normal enclosure with rails screwed to the enclosure. Since the plug in panel was not listed for GE breakers. Then it may be used for din rail breakers as well.

 

[tersh]

Common reason for DIN being so popular, they let you make a busbar out of scrap wire:

Yesterday. I did teardown of a 16A din rail breaker to see what's all the fuss about it and studying the internal mechanism:

It is quite compact and only a small plastic (black above it) can trip it from both from the solenoid and bimetal trigger.

I was wondering why NEC hate it, what is their reason they prefer the larger plug in breakers? Maybe it's really more robust? Remember the US has landed many spacecrafts in Mars that the Europeans couldn't. So are US plug in breakers more superior than din rail MCBs? I'm contemplating this because if plug in are more superior then I can just get another Siemens plug in load center to replace the present locally made panel and bus bar. Or use simple din rail MCBs if they are as robusts as US plug in breakers. what do you think? And why NEC hate it?

 

[mbrooke]

Yesterday. I did teardown of a 16A din rail breaker to see what's all the fuss about it and studying the internal mechanism:

It is quite compact and only a small plastic (black above it) can trip it from both from the solenoid and bimetal trigger.

I was wondering why NEC hate it, what is their reason they prefer the larger plug in breakers? Maybe it's really more robust? Remember the US has landed many spacecrafts in Mars that the Europeans couldn't. So are US plug in breakers more superior than din rail MCBs? I'm contemplating this because if plug in are more superior then I can just get another Siemens plug in load center to replace the present locally made panel and bus bar. Or use simple din rail MCBs if they are as robusts as US plug in breakers. what do you think? And why NEC hate it?

Hard to say which is more superior- they both have their pros and cons.


The NEC is bureaucratic, and as of late its become the manufacturers' marionette as well as UL...


Considering local busbars are a mystery meat, I would go for DIN rail.

 

[kwired]

It's not even listed equipment. I mean, all our plug in panels are locally made with thin bus bar stubs to save metal. We never have US made original GE panel. I have never seen one before in my life. Therefore all our panels were not even listed to take the GE breakers or any brands.

You are chasing the wrong problem, though I do realize given your situation you are trying to chase the one that you think is easier to solve.

If I were to guess, I'd say the legal system there is completely different than here. If people get injured or killed from failures of those electrical systems you have showed us and there are lawsuits that follow with large compensation amounts - that starts to get the attention of everyone involved and eventually starts to make better installation and product standards - even goes too far the other direction at times.

 

[tersh]

You are chasing the wrong problem, though I do realize given your situation you are trying to chase the one that you think is easier to solve.

If I were to guess, I'd say the legal system there is completely different than here. If people get injured or killed from failures of those electrical systems you have showed us and there are lawsuits that follow with large compensation amounts - that starts to get the attention of everyone involved and eventually starts to make better installation and product standards - even goes too far the other direction at times.

In our country. Almost 100% use locally assembled panels and bus bars. And because the GE breakers spring clips can bite the bus bar stubs at the same area as the wire at least. Then it's no problem for 30A and less. For commercial and office building. They use bolt-on to avoid vibrations so no problem with the panels. They have used them for the past 100 years.

Also in residential. A single 75kVA single phase transformer serves 10 houses. So even the short circuit current is low compared to office or commercial building where they own the transformers by themselves.

Another thing is contractor electricians are more aggressive willing to handle live which doesn't happen in homes because there is a main breaker to turn down.

The hazard in residentials.. unless they didn't follow electrical plane and wiring, breaker sizes are really seismic especially shear failure, meaning collapse of the house during earthquake. So the electrical thing is secondary to the more primary danger.

Our country is in the ring of fire and our homes near faults, but the houses are not built to any seismic standards because of contractor cost cutting and not following plans.

 

[kwired]

In our country. Almost 100% use locally assembled panels and bus bars. And because the GE breakers spring clips can bite the bus bar stubs at the same area as the wire at least. Then it's no problem for 30A and less. For commercial and office building. They use bolt-on to avoid vibrations so no problem with the panels. They have used them for the past 100 years.

Also in residential. A single 75kVA single phase transformer serves 10 houses. So even the short circuit current is low compared to office or commercial building where they own the transformers by themselves.

Another thing is contractor electricians are more aggressive willing to handle live which doesn't happen in homes because there is a main breaker to turn down.

The hazard in residentials.. unless they didn't follow electrical plane and wiring, breaker sizes are really seismic especially shear failure, meaning collapse of the house during earthquake. So the electrical thing is secondary to the more primary danger.

The style of breakers common today have only been around for 65-70 years. Can't tell you exacty when GE came out with THQ series but pretty sure it was no earlier than 1950 but probably was around by 1960. Other similar designs were evolving at about the same time.

 

[romex jockey]

That was why I was asking what is the exact thickness of original US GE Panel bus bar stubs using calipers. So if i'd find out our locally manufactured versions are significantly thinner. Then I'd surely have the present panel replaced asap. But if the thickness are close. Then it may be delayed for longer while awaiting expert electrical contractor.

about .094 ....94thousands .......very little deviation ,maybe 1/1000th Tersh

~RJ~

 

[peter d]

As much as I now dislike the NEC, at least it's some level of safety even though many of its rules are pointless. Sure beats the Philipines though. :happyyes:

 

[mbrooke]

As much as I now dislike the NEC, at least it's some level of safety even though many of its rules are pointless. Sure beats the Philipines though. :happyyes:

The Philippines actually go by the NEC:


https://www.pdf-archive.com/2016/06/03/philippine-electrical-code/philippine-electrical-code.pdf


But sadly no one follows it nor are the inspectors honest (they are often payed off).

 

[tersh]

about .094 ....94thousands .......very little deviation ,maybe 1/1000th Tersh

~RJ~

Thanks for it. I'll go to the stores later and look for a caliper. In case I couldn't find accurate ones or with meter like yours. I need to buy one at amazon, what is the exact brand and model you used?

If you have a Siemens PL Load center, kindly measure the bus bar stubs too as mine was already energized. Ultimately this is to prove whether the following advice is false or true. I nearly installed the Siemens GFCI breakers into my locally made plug in panels, but someone told me the following which alarmed me and got me into long path to order an original Siemens PL load center in the US whose shipping cost is more than the unit. This is the reasons no owners use original panels.

The panel expert wrote:

"
The magic snap is not magic. Contact blades are not flat.

One thing you will notice about US breakers in matching panels is that they "Snap" in with a definite resounding snap. And when you try to remove them, the initial force needed to pull them out the first 0.1mm is considerably greater than the force needed to pull them the rest of the way.

That's because the bus bar in the service panel actually has a little "nub" shaped into it, of a specific shape. That shape engages matching curves on the breaker's spring clip. It works like a detent, creating the snap. However the good contact also creates a lot of mating surface area. As such, it runs at sane temperatures during high current flow, which is why UL approves it.

Every panel manufacturer uses a different shape of bus bar, requiring different shaping on the breaker's spring clip. They are different because of patents. Each manufacturer has patented their shape, because they think it outperforms their competitor's shape (and avoids violating their competitor's patents). Eventually patents expire, such as Square D's QO (queue oh) patent expired, permitting Murray/Siemens to manufacture its QD (queue dee) breakers for QO panels. Still, Siemens is unable to make breakers that fit both Murray and QO panels, because they are still different. They are locked into the old designs because new breakers need to fit old and new panels alike.

So when you use an alien breaker, the clips and nubs don't mate as intended by the two manufacturers, and this is not an accident, it's by design. They are not trying to keep you from using alien breakers, they are (were) trying to keep from being sued for patent infringement. Anyway, you end up with the clips only mating at 2-4 points instead of flat surface contact, and point contact like that is only good for a couple of amps before it starts melting, opening, arcing and burning. "

The words "melting, opening, arcing and burning" were etched into my mind then due to previous experience witnessing an arc flash so I bought original Siemens panel for that to ease the fear. So which part of the above statement is true, which is false? I couldn't find the "nub" in "

because the bus bar in the service panel actually has a little "nub" shaped into it, of a specific shape". Have you seen such "nub" yourself? What bus bar have the "nub"?


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[tersh]

about .094 ....94thousands .......very little deviation ,maybe 1/1000th Tersh

~RJ~

Today is holiday in the country where in 1986 millions of people flocked to the street and toppled a dictator giving rise to popularity of People Power Revolution. Unfortunately, it failed in Syria where half a million citizens were killed.

Therefore I went to the single biggest construction store in the country known as Wilcon Depot (what is US version of this, Home Depot?):

Fortunately. I was able to find an digital caliper:

I then went to their plug in panel section. In the store, one half is plug in section, one half is din rail MCBs section (since both are used in the country):

I opened and measured the bus bar stub of the plug in panel:

it measured about 0.0835 or 0.083 when pressed with pressure. You measured the original GE bus bar stub to be 0.094. Is the difference significant? If the GE spring clips were flat, and applying basic trigo, would the contact only be at the edge with mostly gap in the middle?

This is zoom out of it:

More zoomed out.

This is measurement of another local plug in panel brand.

Zoomed out.

From the measurements and previous handling of the Siemens. I think the Siemens bus bar stub is thicker than the GE bus bar stub 0.094 thickness. I guess the Siemens PL center stub measures about 0.100 or more? How much can this really affect the contact areas if north American panels and breakers were mixed?

 

[mbrooke]

Is there any panel with a ground bar? Can you even install or buy one?

 

[tersh]

Is there any panel with a ground bar? Can you even install or buy one?

No. There aren't any panels with ground bars and all stores don't stock any ground bars bec residential never used it. Even if the owners put ground bar. The appliances has no EGC. For example microwave oven has no extra third wire. No one here would drill a hole in the microwave oven to connect one bec it can destroy the warrantee or appliances. You can get ground bar by ordering at amazon. For office & commercial building that need customs bolt-on panels. If your electrical plans require third ground wires. Then you need to get it fabricated and order special ground bars at industrial electrical suppliers. But for residential that uses ready made panels, absolutely no access to ground wires bec all stores and locally made residential panels dont include any ground bars.