Beneteau 37 circuit breaker replacement

[Mechone]

Thank you for your reply Mechone, I never came across this issue before. I'll read some more before I comment but something seems odd here as I've not seen any such derating on the ABYC standards. Have you?

The insulation value of the wire allows the wire to flow more amps and run hotter , you must rate at what the termination value is or you will melt the terminal ,like above ,so the wire must be derated to that value of the termination so the wire size must increase . Has nothing to do with what the wire is able to run in amps ,the termination value would have to be 105c which is 221 degrees F. Look I have purchased tons of machines from around the world ,many from the US and not one machine has met Canadian code ,its very strick. I have a 12 million dollar machine coming from Germany that is UL certified , it must be ULC or CSA certified which is a much tougher code . I had a machine come from China from a US company 200k rewire /breakers power supplies ,etc ,yet they have 150 of them running in the US. So to be safe #8 40 amps covers derating if I look at CSA chart . ABYC is only a US standard

 

[APP314]

The insulation value of the wire allows the wire to flow more amps and run hotter , you must rate at what the termination value is or you will melt the terminal ,like above ,so the wire must be derated to that value of the termination so the wire size must increase . Has nothing to do with what the wire is able to run in amps ,the termination value would have to be 105c which is 221 degrees F. Look I have purchased tons of machines from around the world ,many from the US and not one machine has met Canadian code ,its very strick. I have a 12 million dollar machine coming from Germany that is UL certified , it must be ULC or CSA certified which is a much tougher code . I had a machine come from China from a US company 200k rewire /breakers power supplies ,etc ,yet they have 150 of them running in the US. So to be safe #8 40 amps covers derating if I look at CSA chart . ABYC is only a US standard

Mechone,



I’m trying to understand the reasons behind NEC’s requirement and the apparent discrepancy with ABYC guidelines as well as what the rationale behind each one was.



As far as I can tell the reason NEC requires derating of the cables is to match the cable max (developed) temperature to the breaker’s maximum ambient operating temperature so the installation can perform at its rated value in steady state conditions. This makes the cable appear thermally to the breaker as the rest of the environment. Under those conditions the breaker will be actually hotter than this temperature as it will be shedding heat to the surrounding space. This assures the breaker performs close to it rated capacity. As the temperature increases, the tripping curve will move to the left and the breaker will trip at much lower current than its related value. This, however, doesn’t imply that the breaker will be destroyed by an increase in temperature. The breaker itself always trips a the same temperature given by the mechanical and thermal properties of the design. How much current flow is required to reach this temperature will depend on the ambient temperature. Both EATON and Siemens list their plastic materials as capable of maintaining their structural integrity at temperatures in excess of 200 °C. Before the housing reaches this temperature the breaker would have tripped.

The result will be that under continuous load conditions the breaker will trip at a lower steady current than rated, but no fire hazard would be created. This is at least my understanding based on the several papers and standards I’ve read so far.

Alejandro

 

[Mechone]

Mechone,



I’m trying to understand the reasons behind NEC’s requirement and the apparent discrepancy with ABYC guidelines as well as what the rationale behind each one was.



As far as I can tell the reason NEC requires derating of the cables is to match the cable max (developed) temperature to the breaker’s maximum ambient operating temperature so the installation can perform at its rated value in steady state conditions. This makes the cable appear thermally to the breaker as the rest of the environment. Under those conditions the breaker will be actually hotter than this temperature as it will be shedding heat to the surrounding space. This assures the breaker performs close to it rated capacity. As the temperature increases, the tripping curve will move to the left and the breaker will trip at much lower current than its related value. This, however, doesn’t imply that the breaker will be destroyed by an increase in temperature. The breaker itself always trips a the same temperature given by the mechanical and thermal properties of the design. How much current flow is required to reach this temperature will depend on the ambient temperature. Both EATON and Siemens list their plastic materials as capable of maintaining their structural integrity at temperatures in excess of 200 °C. Before the housing reaches this temperature the breaker would have tripped.

The result will be that under continuous load conditions the breaker will trip at a lower steady current than rated, but no fire hazard would be created. This is at least my understanding based on the several papers and standards I’ve read so far.

Alejandro

Okay then how does that relate to a plug being only rated for 60C @50 amps as per video i posted. At the end of the day for 40 years its been #8 for 40 amps #10 30 amps and I would rather be bigger than smaller that might not meet codes .