Brymen BM789

[joeqsmith]

Someone wrote me once about repairing toasters or such and they were all concerned with arc flash.    

[Neutrion]

Yes, that is why I used quote marks. So wanted to get a workaround for the missing overrange indication. But it seems that above 1V DC offset the displayed walue can be from 0 to anything, so there is no way of knowing it from the displayed value.

What do you think about the FW checking 1-2X a second the DC value? Would that be possible at all?
How much time does it take for the controller to switch from one mode to another? If I press the button it takes quiet a long time, so if this is HW related than that would be a no-go.

[Fungus]

Someone wrote me once about repairing toasters or such and they were all concerned with arc flash.   

Understandable. Anybody who's ever stuck a knife in a hot toaster to get the bread out knows what can happen in there.

[Neutrion]

The reason for getting the bread out only with proper CAT rated equipment!

[AVGresponding]

Someone wrote me once about repairing toasters or such and they were all concerned with arc flash.   

Understandable. Anybody who's ever stuck a knife in a hot toaster to get the bread out knows what can happen in there.

This is a thing? I mean to say, there are people out there who are foolish enough to do such a thing?

[Monkeh]

Someone wrote me once about repairing toasters or such and they were all concerned with arc flash.   

Understandable. Anybody who's ever stuck a knife in a hot toaster to get the bread out knows what can happen in there.

This is a thing? I mean to say, there are people out there who are foolish enough to do such a thing?

Have you met the average American?

[AVGresponding]

Someone wrote me once about repairing toasters or such and they were all concerned with arc flash.   

Understandable. Anybody who's ever stuck a knife in a hot toaster to get the bread out knows what can happen in there.

This is a thing? I mean to say, there are people out there who are foolish enough to do such a thing?

Have you met the average American?

I don't know. If I have, they didn't identify themselves as such.   

[Fungus]

Have you met the average American?

I don't know. If I have, they didn't identify themselves as such.   

(Insert George Carlin quote here...)

[bdunham7]

This is a thing? I mean to say, there are people out there who are foolish enough to do such a thing?

Think of it as a skill building exercise like that kid's game "Operation".

[bdunham7]

Have you met the average American?

I suppose you Brits do everything prim and proper like unplugging  your toasters before probing and shutting your car engines off before changing the fan belt?

https://youtu.be/BQhfcdQf1QA

[AVGresponding]

Have you met the average American?

I suppose you Brits do everything prim and proper like unplugging  your toasters before probing and shutting your car engines off before changing the fan belt?

https://youtu.be/BQhfcdQf1QA

I've done lots of dangerous things in my time. Some were for pay, some for duty, some for fun, and some out of ignorance. I can honestly say I've never done anything dangerous for toast.

[Per Hansson]

Someone wrote me once about repairing toasters or such and they were all concerned with arc flash.   

Understandable. Anybody who's ever stuck a knife in a hot toaster to get the bread out knows what can happen in there.

This is a thing? I mean to say, there are people out there who are foolish enough to do such a thing?

I'm willing to bet there are more people killed by toasters than sharks every year!

[AVGresponding]

Someone wrote me once about repairing toasters or such and they were all concerned with arc flash.   

Understandable. Anybody who's ever stuck a knife in a hot toaster to get the bread out knows what can happen in there.

This is a thing? I mean to say, there are people out there who are foolish enough to do such a thing?

I'm willing to bet there are more people killed by toasters than sharks every year!

I suppose we need something to scrape the flaky bits off the bottom of the gene pool.   

[joeqsmith]

I think it was an American who asked.

Not too surprised by by people getting a poke from their appliances.  I was surprised they were concerned about an arc flash.   I wonder if there's a special group that consider ANY spark an arc flash event.  Maybe the same group that always discusses safety here?  That would explain a lot.   

That can't be it because it seems many are not from the United States.   

[AVGresponding]

I think it was an American who asked.

Not too surprised by by people getting a poke from their appliances.  I was surprised they were concerned about an arc flash.   I wonder if there's a special group that consider ANY spark an arc flash event.  Maybe the same group that always discusses safety here?  That would explain a lot.   

That can't be it because it seems many are not from the United States.

"arc fault protection" is the latest buzz-phrase in electrical installation here. Lots of profit to be made implementing the new regs, which is a good thing, right?   

[2N3055]

I think it was an American who asked.

Not too surprised by by people getting a poke from their appliances.  I was surprised they were concerned about an arc flash.   I wonder if there's a special group that consider ANY spark an arc flash event.  Maybe the same group that always discusses safety here?  That would explain a lot.   

That can't be it because it seems many are not from the United States.

"arc fault protection" is the latest buzz-phrase in electrical installation here. Lots of profit to be made implementing the new regs, which is a good thing, right?   

There is a lot of confusion because there is a failure mode where in residential installations, sometimes bad connections cause local sparking and contact resistance overheating of connections, that can damage insulation to the point of it itself becoming conductive and starts heating by itself and can create fires.. They realized that this bad contact sparking could be detected by looking into current spectrum etc...

Some of that detection technology came from arch flash fault protection tech (current signature analysis), so marketing jumped at opportunity and used all the drama and buzzwords to make appear that is some sort of "distant cousin" of arc flash accidents.. And you should be afraid, very afraid.. Jerks... They call it "arc protection", not "arc flash fault protection" so technically they didn't say it is the same..

Slow smoldering of insulation and arc flash accidents shouldn't be confused...

Arc flash accidents cannot happen if there is not enough energy.
Non professional shouldn't work on anything where arc flash accident can happen.
And probably won't have access to anything where it can happen.

OTOH, people nowadays have large machinery in their garages, and it is tempting to try to repair failed VFD or welding inverter by yourself. Some of these can have serious DC capacitor bank, that can hurt you. Those can seriously hurt your face, hands, eyes and hearing...
When shorted, compared to real arc flash accident, they are mere large firecrackers compared to the block of C4 .
But you can get seriously hurt by firecracker if you put it next to your face or hold it in a closed hand.


 

[bdunham7]

"arc fault protection" is the latest buzz-phrase in electrical installation here. Lots of profit to be made implementing the new regs, which is a good thing, right?   

I just had a fire that did thousands of dollars of damage that was due to a defective device arcing internally.  I have AFCI breakers on certain circuits, but this was a 240VAC circuit for the swimming pool, so GFCI not AFCI is what is installed.  AFCI might just have prevented that fire. 

[joeqsmith]

There is a lot of confusion because there is a failure mode where in residential installations, sometimes bad connections cause local sparking and contact resistance overheating of connections, that can damage insulation to the point of it itself becoming conductive and starts heating by itself and can create fires.. They realized that this bad contact sparking could be detected by looking into current spectrum etc...

Some of that detection technology came from arch flash fault protection tech (current signature analysis), so marketing jumped at opportunity and used all the drama and buzzwords to make appear that is some sort of "distant cousin" of arc flash accidents.. And you should be afraid, very afraid.. Jerks... They call it "arc protection", not "arc flash fault protection" so technically they didn't say it is the same..

Slow smoldering of insulation and arc flash accidents shouldn't be confused...
...

I watch very few electronics channels and even less having to do with electrical circuits.  That said, I subscribed to John Ward's channel years ago and have watched several of his videos.   

He produced several on this subject.  I left him a comment after seeing one of his early ones and was glad to see him continue to provide more details about them.    I tried to procure that exact same part from Eaton but wasn't able to locate one in the USA. 

[Neutrion]

One more question about the BM789 which annoys me a bit:
The treshold for continuity is between 100Ohm and 420Ohm.
First I am not sure what this intervall means. But more importantly, isn't 420Ohm too high for finding shorts? I got used to 10-20Ohm but this one beeps all the time. Now I see that the 869 has also 200Ohm treshold but they doubled that with the 789. So there must be some application for it... What is it? I can't think it is just accidentally so high.
(The continuity voltage is 2,3 Volts measured with a multimeter.)

[bdunham7]

The treshold for continuity is between 100Ohm and 420Ohm.
What is it? I can't think it is just accidentally so high.

It might be that they use a low test current.  Unfortunately, continuity threshold is a spec that we will all never agree on, so the only solutions are to either live with what you get or find a meter that has selectable thresholds--which is pretty rare.

[2N3055]

"arc fault protection" is the latest buzz-phrase in electrical installation here. Lots of profit to be made implementing the new regs, which is a good thing, right?   

I just had a fire that did thousands of dollars of damage that was due to a defective device arcing internally.  I have AFCI breakers on certain circuits, but this was a 240VAC circuit for the swimming pool, so GFCI not AFCI is what is installed.  AFCI might just have prevented that fire.

House fires are serious enough. I wasn't saying that.
Those AFCI devices are definitely something that might save many houses and even lives..

It's just, that, large arc flash accident is a very violent explosive event that is similar to someone dropping bomb in how dangerous it is..

[joeqsmith]

If the laws mandate these devices and you end up with an electrical fire, are they liable?  Seems like they could be.

[bdunham7]

If the laws mandate these devices and you end up with an electrical fire, are they liable?  Seems like they could be.

They could be if the plaintiff could prove that the device did not perform as expected or required by the relevant standard, but that would be a lot more difficult than a strict liability case.  My guess is that AFCI manufacturers will face liability in house fire cases if they haven't already.  I'm not aware of any current such cases, but since most cases settle before they see the light of day, there could be many.

[Fungus]

My guess is that AFCI manufacturers will face liability in house fire cases if they haven't already.  I'm not aware of any current such cases, but since most cases settle before they see the light of day, there could be many.

There's a ton of fake devices out there:



How do you make 100% sure you aren't installing one?

[AVGresponding]

My guess is that AFCI manufacturers will face liability in house fire cases if they haven't already.  I'm not aware of any current such cases, but since most cases settle before they see the light of day, there could be many.

There's a ton of fake devices out there:



How do you make 100% sure you aren't installing one?

By having the work done by a reputable electrician using quality brand named goods from a reliable bricks and mortar source.

That's not a 100% guarantee by any means, but should lower the risk to very, very low levels. I haven't (yet) seen any counterfeit brand named items (Eaton, Schneider, Hager etc) from the big wholesalers (Edmundsons, CEF etc).

I have come across some fake BS1362 fuses, but unfortunately couldn't say where they came from.