like I said, its working perfect.
Best advice you will ever get.
running 48 amps on a 50 amp circuit for more than 2 hours is really risky and there are several problems:
fire.
Thanks for the master classrunning 48 amps on a 50 amp circuit for more than 2 hours is really risky and there are several problems:
Now the failure modes here are:
- depending on the type/quality of the breaker it may trip during charging while you're asleep - there are different types of breakers that behave differently for different types of load - over time it may cause the breaker to "age" and begin tripping more frequently even though technically you've not exceeded 50 amps
- depending on the actual wire gauge 48 amps on 8 gauge wire will ACCUMULATE a LOT of heat across a 2-9 hour charging session. The problem here is thermal-stress accumulation over time…leading to wire insulation fatigue increasing the chance of insulation failure in the future…it will work right up until the point it doesn't
- When the wire heats up (and it WILL heat up at 48 amps) it expands, this expands the insulation (which is also warm and now a bit mushy due to the heat) - when the wire cools it will contract as will the insulation and add just a fractional bit of fatigue to insulation - next time it expands/contacts it will be ever so slightly less resilient…
- more heat = more expansion - which ='s more contraction which equals more fatigue
- over time this thermal-breathing warming/cooling stresses the plastic insulation and eventually it could crack/fail allowing a short and potential fire
- so one day during it's expansion/contraction a small crack will begin to develop and eventually a "breech" which can/will lead to a short…
- 8 gauge wire will be 30-60F higher temp than 6 gauge wire at the same 48 amp load - 4 gauge wire will only experience a 10-20F temp rise at 48 amp load
- so there is less thermal expansion at the same amp loads - leading to less fatigue on the wire's insulation - increasing the longevity of the insulation…
- Also over time wire insulation becomes more brittle - reducing it's resistance to fatigue and increasing the fatigue rate in the fact of thermal expansion/contraction - it gets less resilient over time - which means you want to stress it LESS
48 amp continuous load (2 hours or more) should be run on at least 6 gauge wire (preferably 4 gauge) to reduce the thermal loads, which reduces expansions/contraction and thereby thermaly stresses the wire insulation less dramatically reducing the chance of insulation failure due to long duration accumulated thermal stress.
- un-necessary breaker trips - waking up to your car not charged over night cause the breaker is fatigued from overuse - not so bad
- And/Or wire insulation failure leading to short-circuit and actual
the issue here is _NOT_ the breaker - it's the wire gauge typically installed along with a 50 amp breaker…10/8 gauge wire can "pass" a building electical code inspection for a 50 amp circuit - but 10/8 gauge wire is _NOT_ rated for continuous load at 48 amps - it's rated for 40 amp continuous loads - or 50 amp loads for 2 hours or less…it's the duration of the load that is the factor here no the absolute value of the amps - we're managing accumulated thermal stress over time to avoid long term fatigue failures…
oh and by the way these sorts of code recommendations are not just BS engineering stuff pulled out of thin air - most of these types of recommendations are from accumulated actual experience from failure analysis when these sorts of recommendations were not present in the past…i.e. wow this failed spectacularly and if we'd simplly used 6 gauge wire instead of 8 gauge wire this would've never happened.
now if you have 4/6 gauge wire on your 50 amp breaker - then there is no issue - it's the wire that is the risk here, not the breaker and there is no safety issue, but at that point swapping the breaker is both easy/cheap and will match building code because you have appropriate wire/gauge for a continous 48 amp load - a new 60 amp breaker is $50 or less and should take no more than 1 hour of labor to swap - and boom your done…
the problem here is not the breaker, and it will work (you can pull 100 amps across any gauge wire for some period of time, but if it's 14 gauge wire it _WILL_ eventually fail)
the problem here is accumulated thermal stress over time will lead to insulation failure if your wire gauge is not up to the task - and if the wire gauge isn't rated for 48 amps (the insulation is not rated for 48 amps) it's not a matter of "if" it will fail, it's simply a matter of "when" it will fail…mostly likely while you're asleep about 3 hours into a charging session which started at 11 pm - so about 2 am while everyone's asleep if you're following overnight charging patterns.
Wire used to feed the charger is 6.running 48 amps on a 50 amp circuit for more than 2 hours is really risky and there are several problems:
Now the failure modes here are:
- depending on the type/quality of the breaker it may trip during charging while you're asleep - there are different types of breakers that behave differently for different types of load - over time it may cause the breaker to "age" and begin tripping more frequently even though technically you've not exceeded 50 amps
- depending on the actual wire gauge 48 amps on 8 gauge wire will ACCUMULATE a LOT of heat across a 2-9 hour charging session. The problem here is thermal-stress accumulation over time…leading to wire insulation fatigue increasing the chance of insulation failure in the future…it will work right up until the point it doesn't
- When the wire heats up (and it WILL heat up at 48 amps) it expands, this expands the insulation (which is also warm and now a bit mushy due to the heat) - when the wire cools it will contract as will the insulation and add just a fractional bit of fatigue to insulation - next time it expands/contacts it will be ever so slightly less resilient…
- more heat = more expansion - which ='s more contraction which equals more fatigue
- over time this thermal-breathing warming/cooling stresses the plastic insulation and eventually it could crack/fail allowing a short and potential fire
- so one day during it's expansion/contraction a small crack will begin to develop and eventually a "breech" which can/will lead to a short…
- 8 gauge wire will be 30-60F higher temp than 6 gauge wire at the same 48 amp load - 4 gauge wire will only experience a 10-20F temp rise at 48 amp load
- so there is less thermal expansion at the same amp loads - leading to less fatigue on the wire's insulation - increasing the longevity of the insulation…
- Also over time wire insulation becomes more brittle - reducing it's resistance to fatigue and increasing the fatigue rate in the fact of thermal expansion/contraction - it gets less resilient over time - which means you want to stress it LESS
48 amp continuous load (2 hours or more) should be run on at least 6 gauge wire (preferably 4 gauge) to reduce the thermal loads, which reduces expansions/contraction and thereby thermaly stresses the wire insulation less dramatically reducing the chance of insulation failure due to long duration accumulated thermal stress.
- un-necessary breaker trips - waking up to your car not charged over night cause the breaker is fatigued from overuse - not so bad
- And/Or wire insulation failure leading to short-circuit and actual
the issue here is _NOT_ the breaker - it's the wire gauge typically installed along with a 50 amp breaker…10/8 gauge wire can "pass" a building electical code inspection for a 50 amp circuit - but 10/8 gauge wire is _NOT_ rated for continuous load at 48 amps - it's rated for 40 amp continuous loads - or 50 amp loads for 2 hours or less…it's the duration of the load that is the factor here no the absolute value of the amps - we're managing accumulated thermal stress over time to avoid long term fatigue failures…
oh and by the way these sorts of code recommendations are not just BS engineering stuff pulled out of thin air - most of these types of recommendations are from accumulated actual experience from failure analysis when these sorts of recommendations were not present in the past…i.e. wow this failed spectacularly and if we'd simplly used 6 gauge wire instead of 8 gauge wire this would've never happened.
now if you have 4/6 gauge wire on your 50 amp breaker - then there is no issue - it's the wire that is the risk here, not the breaker and there is no safety issue, but at that point swapping the breaker is both easy/cheap and will match building code because you have appropriate wire/gauge for a continous 48 amp load - a new 60 amp breaker is $50 or less and should take no more than 1 hour of labor to swap - and boom your done…
the problem here is not the breaker, and it will work (you can pull 100 amps across any gauge wire for some period of time, but if it's 14 gauge wire it _WILL_ eventually fail)
the problem here is accumulated thermal stress over time will lead to insulation failure if your wire gauge is not up to the task - and if the wire gauge isn't rated for 48 amps (the insulation is not rated for 48 amps) it's not a matter of "if" it will fail, it's simply a matter of "when" it will fail…mostly likely while you're asleep about 3 hours into a charging session which started at 11 pm - so about 2 am while everyone's asleep if you're following overnight charging patterns.
I'd consult with electrician to confirm 6 gauge wire would pass building code inspection for 60 amp breaker - if it would - I'd swap the breaker and you'll be good - I am not a licensed/bonded electrician and regional building code vary.
I did. Comfirmed 6 is enough wire for the 48A load.
Thanks.
