DC and AC circuitbreaker>>>?
- Thread starter MAGICPIE3FOCUSPOWER
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MAGICPIE3FOCUSPOWER
10 kW
Yup I have just bought at local shop 230V AC/DC 63A circuit breakers.
Do you guys one is enough or two parallel connected is better?
Do you guys one is enough or two parallel connected is better?
MAGICPIE3FOCUSPOWER
10 kW
I am running 75V pack with 3KW motor.
So one should be okay?
So one should be okay?
Nope, there's no "precharge" inside any breaker I've ever seen or heard of.madin88 said:
Precharge is not a breaker's job; instead it is meant to break a circuit that is overloaded (determined by the rating of the breaker).
If you use a large enough breaker that is made well enough, the arc damage from using it as a switch instead of / in addition to it's designed job as a breaker will take quite a while to damage it beyond functional use.
A misleading statement about the 'designed job'....amberwolf said:
Many marine breakers and solar breakers are specifically designed to be used both as breakers and as switches.
The Midnite solar MNEDC series breakers are rated at 5000 cycles at full load. I use similar magneto-hydraulic toggle breakers from Blue Sea Systems (A-series) and (C-series) that are rated at 10,000 cycles.
Use without precharge briefly exceeds the current rating and so may eventually lead to some issue - but that is a separate from the claim of being designed only for use as a breaker - not as a switch. That said, the marine and solar units above have max fault currents of 5000A or more and so have pretty hearty contacts (fault current = current that can be interrupted without damage).
now, why does Adaptto or Adaptto users submit that a precharge circuit is not necessary anymore when using such home braker?
what we know is most brakers are designed to switch under load, but do they switch instant or is there some ramp up so it does not hurt the caps?
what we know is most brakers are designed to switch under load, but do they switch instant or is there some ramp up so it does not hurt the caps?
Doctorbass
100 GW
teklektik said:
I guess that max current is calculated by taking the battery voltage divided by ( the total wires resistance + the battery internal resistance) as the capacitor is seen as a 0 ohm when fully discharged
ex: let say we have a ebike 100V battery with 50 milliohm resistance and 4 foots of 10 awg wire ( 4 milliohm)
This result to 100V / 54miliohm = 1852A so in the worst conditions the interrupt/fault current is not exceeding the 5000A witch would be good in this condition....
Doc
MAGICPIE3FOCUSPOWER
10 kW
Thanks all!
I hope this kind of circuit breaker will last long, due I am using as a normal switch for daily switching on/off
I hope this kind of circuit breaker will last long, due I am using as a normal switch for daily switching on/off
Alan B
100 GW
Solar systems are constant current DC, not equivalent to our ebike battery to capacitor bank service. The peak current available from a lithium pack to charge the controller's input capacitor bank is very high, likely beyond their "normal use" design expectation for AC or solar DC in switch or circuit breaker service.
I'm sure these solar breakers can handle the ebike turn-on surge for awhile, but it may shorten their life considerably. I'm planning to use a precharge circuit, the cost of adding a momentary pushbutton and resistor is very low, and the cost of replacing breakers or having them start faulting at high current due to increased contact resistance is just not worth it.
I'm sure these solar breakers can handle the ebike turn-on surge for awhile, but it may shorten their life considerably. I'm planning to use a precharge circuit, the cost of adding a momentary pushbutton and resistor is very low, and the cost of replacing breakers or having them start faulting at high current due to increased contact resistance is just not worth it.
http://endless-sphere.com/forums/viewtopic.php?f=2&t=66455&p=999943#p999726
Sorry, wasn't meant to mislead, just that most of the breakers people seem to end up using or wanting to use are not designed as switches (or rather, not ones for frequent/repetitive switching like will be done on many bikes, potentially multiple cycles a day).
The other issue is that brought up by others above, that the initial current thru the breaker is likely to be very high for the first instant, because of the discharged caps in the controller. I'm not sure what kind of initial load these breakers would normally see in solar or marine use, when used as switches. It might be the same, and if so, they're probably designed for that. IF not, they may not be, and then contact wear could be higher than normal.
I use a DC-rated breaker on CrazyBike2, and it gets switch cycled a minimum of twice a day (on, off, on, off), and sometimes 3 times if I turn it off when I get home and then back on again later to charge, instead of charging immediately (if I get home before 9pm in "winter peak power hours" then I wait till after that, as peak power hours cost more, I forget the time for summer hours).
Even more cycles per day when I make side trips. Weekly, on average, I probably cycle the switch 20 times. 52 weeks in a year gives me 1040 cycles, so lets' call it 1000 cycles a year. I think I've had the breaker on the bike since 2009 or 2010, so let's say there's 5000 cycles on it now.
No issues so far with it, and I know there is a pretty massive spark in there, as I have forgotten to turn it off when hooking the battery back up after maintenance/etc., and it's quite a pop with the caps of two controllers and a DC-DC to charge up (enough to scare the dogs out of the room and light it up if it's dark).
Sorry, wasn't meant to mislead, just that most of the breakers people seem to end up using or wanting to use are not designed as switches (or rather, not ones for frequent/repetitive switching like will be done on many bikes, potentially multiple cycles a day).
The other issue is that brought up by others above, that the initial current thru the breaker is likely to be very high for the first instant, because of the discharged caps in the controller. I'm not sure what kind of initial load these breakers would normally see in solar or marine use, when used as switches. It might be the same, and if so, they're probably designed for that. IF not, they may not be, and then contact wear could be higher than normal.
I use a DC-rated breaker on CrazyBike2, and it gets switch cycled a minimum of twice a day (on, off, on, off), and sometimes 3 times if I turn it off when I get home and then back on again later to charge, instead of charging immediately (if I get home before 9pm in "winter peak power hours" then I wait till after that, as peak power hours cost more, I forget the time for summer hours).
Even more cycles per day when I make side trips. Weekly, on average, I probably cycle the switch 20 times. 52 weeks in a year gives me 1040 cycles, so lets' call it 1000 cycles a year. I think I've had the breaker on the bike since 2009 or 2010, so let's say there's 5000 cycles on it now.
No issues so far with it, and I know there is a pretty massive spark in there, as I have forgotten to turn it off when hooking the battery back up after maintenance/etc., and it's quite a pop with the caps of two controllers and a DC-DC to charge up (enough to scare the dogs out of the room and light it up if it's dark).
I have two breakers in series, one I use as a switch, attached to an external cable, so I can pull and push it on and off from outside the battery box, the other is just used as a circuit breaker in case of a fault, iv had it going for 6 months and it works fine.
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