Do your circuit breakers ever trip from vibration?
- Thread starter ryan
- Start date
John in CR
100 TW
You must be Chinese. They've gotten on a kick about putting circuit breakers on crap low power scooters.
Think about what you need a circuit breaker for. It should be an extremely rare or never occurrence. Use a fuse instead, small and simple.
Think about what you need a circuit breaker for. It should be an extremely rare or never occurrence. Use a fuse instead, small and simple.
joe tomten
100 W
the ole' square-d QO series is supposedly dc rated and used in the solar industry for string combiners: 100amp & 10,000 amp interruptible.
I keep thinking it would make a nice switch as well.
$53 from home depot
http://www.google.com/products/catalog?hl=en&q=square+d+qo+100+amp+breaker&um=1&ie=UTF-8&tbm=shop&cid=6040039760248232284&sa=X&ei=zOlPT9h1kLfQAdHVqd8N&ved=0CG0Q8wIwAA
I keep thinking it would make a nice switch as well.
$53 from home depot
http://www.google.com/products/catalog?hl=en&q=square+d+qo+100+amp+breaker&um=1&ie=UTF-8&tbm=shop&cid=6040039760248232284&sa=X&ei=zOlPT9h1kLfQAdHVqd8N&ved=0CG0Q8wIwAA
Rassy
1 MW
I don't agree. I've used circuit breakers (about $15 from Wilderness Energy) for years, mainly as an on off switch. WE said they were for wusses that couldn't handle the spark when plugging in the controller, and they are right, and I haven't had one fail yet. Beats having to set up a precharge circuit in my mind. I also use a 40 amp fuse, and those I have blown. 
http://www.powerwerx.com/fuses-circuit-protection/resettable-circuit-breaker-cooper-bussmann.html
That is very similar to the one I'm using. I like the idea of using it as an on/off switch though! might make life easier on my controller! Will have to relocate it out of the battery boxes to fit more batteries anyway.
That is very similar to the one I'm using. I like the idea of using it as an on/off switch though! might make life easier on my controller! Will have to relocate it out of the battery boxes to fit more batteries anyway.
John in CR
100 TW
Unless you're using an RC ESC for a controller a proper on-off switch carries less than 0.10 amps, so almost any switch will work, though I recommend key switches, not so much for the anti-theft, but more for the anti-accident of some little kid switching the bike on and twisting the throttle. A switch on your power mains is wired incorrectly, and just because some have gotten away with it doesn't make it correct. Needing a precharge resistor isn't much better, because that means you're pulling the battery off the bike frequently. Do people pull the gas tanks off their cars or motorcycles frequently??? Of course not. It's great that the pedalists kicked off the ebike revolution, but it's time to let go of the silliness that works for ebikes only capable of my 90 yearold grandma's pedal trike speeds.
I've used a Blue Seas 50A breaker for 850 miles on a hardtail with no difficulties. These marine breakers have been used for decades on boats that get slammed into waves so hard it will bring you to your knees. Don't worry about it.
Rassy
1 MW
John said:
I have an easy to reach little toggle switch, could also be a key switch, that turns my controller off so the throttle can't be accidently hit. However, I also have a switch on my power "mains" (the heavy duty breaker), for several reasons. This switch not only cuts off all power to the controller to prevent any drain, but also turns off the watts up meter and the directly wired front and rear lights. Of course this stuff can be done differently, but it certainly is handy, isn't getting away with anything, and when I do occassionally switch out a battery it avoids the spark that destroys connectors. Just my opinion.
John, I'm going to completely disagree with you here. Also, a lot of you great guys on this forum seem to assume that everyone here is interested only in high power high speed bikes. Many of us are very happy with our legal 20 MPH top speed systems and have no interest in personally racing or running fast bikes.
I have an easy to reach little toggle switch, could also be a key switch, that turns my controller off so the throttle can't be accidently hit. However, I also have a switch on my power "mains" (the heavy duty breaker), for several reasons. This switch not only cuts off all power to the controller to prevent any drain, but also turns off the watts up meter and the directly wired front and rear lights. Of course this stuff can be done differently, but it certainly is handy, isn't getting away with anything, and when I do occassionally switch out a battery it avoids the spark that destroys connectors. Just my opinion.
E-racer
1 kW
teklektik said:
well said! Breakers are the best! You cant use a fuse as a main cut off switch, lol.
John in CR
100 TW
You can only lead a horse to water. FWIW, power level is irrelevant. Keys are used to switch on the most and least powerful cars, and neither has their gas tanks pulled on a regular basis, and neither has a fuel line shutoff valve instead of just a keyswitch to turn them on. Give up this ridiculousness that is a carryover from the old days of brushed motors where a mains interrupt switch of some kind was required in the name of safety because certain failure modes meant a runaway condition. Shut down the power to the controller brain and a brushless motor can't run, period.
bigmoose
1 MW
For record: Square D QO Breaker Series:
E-racer
1 kW
John in CR said:
It is to my advantage to be able to turn off the main power wires.
Rassy
1 MW
Come on John, lighten up, we don't all want to build electric motorcycles. One of my favorite pasttimes is riding along a muti-purpose path at 10 mph enjoying the scenery, getting some fresh air and exercise, talking to the dog walkers, etc.
Back on topic, I have three batteries for longer rides but normally only use one for local rides. However, I cycle all three batteries for their health and being able to disconnect the power is handy, in addition to the things I mentioned earlier.
I really don't understand why you are so against having an adequate switch between the battery and controller, and more importantly why you feel it's necessary to try to make us feel like idiots for using such a switch.
ryan
10 kW
Interesting. I have two circuit breakers with different trip thresholds.
Here's the experiment:
1) Set both to "on"
2) Drop both from 3 inches up onto bench where forces want to trip the breaker to "off"
Result: 1 trips (the BlueSea one) and the other doesn't (the Solar one)
3) Repeat at 6"
Result: Same result
I didn't want to drop it higher to avoid unnecessary damage. But it's clear that all breakers are not alike in terms of bump and vibration resistance.
(also, at less than 3 inches none of them trip)
Here's the experiment:
1) Set both to "on"
2) Drop both from 3 inches up onto bench where forces want to trip the breaker to "off"
Result: 1 trips (the BlueSea one) and the other doesn't (the Solar one)
3) Repeat at 6"
Result: Same result
I didn't want to drop it higher to avoid unnecessary damage. But it's clear that all breakers are not alike in terms of bump and vibration resistance.
(also, at less than 3 inches none of them trip)
ryan
10 kW
Wait, are you saying pre-charge isn't necessary with circuit breakers instead of switches? Or the other way around? (or none of the above!?)
Rassy said:
E-racer
1 kW
ryan said:
You don't need a precharge resistor with a breaker. I always run one anyway though. It relieves the stress created by the arc on the contacts inside the breaker.
10 kW
John in CR said:
As far as starting a car, the key only energizes the solenoid. The contacts in the solenoid do the heavy lifting. You can start a Ferrari with a piece of 20g solid in the right place but you'll burn a hole in your f-ing hand if you try that in the starter circuit.
People are using circuit breakers as switches because their contacts are rated for the mains current. They aren't using them as fuses.
Not really. These breakers are designed to do double duty as protection/power switches. I also use the breaker as primary protection for the controller and harness wiring. I've had controller shorts and the breaker has tripped without fail whereas the MaxiFuses with the same Amp rating in series in the same circuit have never blown (located in the battery packs). The marine and solar breakers being discussed are magnetic and trip PDQ much in the manner of a relay pulling in.pdf said:
Here's the time delay specs for MaxiFuses (moderately popular ebike protection choice)
Here's the same specs for the Blue Sea Breakers
View attachment 2
Example: for a 200% over-rating draw (100A) against a 50A rating, the max/min trip times for the MaxiFuse 80v, MaxiFuse 32v, and Breaker are respectively: 60s/2s, 50s/10s, and 20s/0.4s
Example: for a 600% over-rating draw (300A) against a 50A rating, the max/min trip times for the MaxiFuse 80v, MaxiFuse 32v, and Breaker are respectively: 1.0/0.04, 1.0s/0.2s and 1.1s/0.02s
The breaker outperforms or at worst matches the fuse.
10 kW
Let me re-phrase: there are four posts on this thread where clearly the primary point of the circuit breaker is for cutting off the mains power without either a pre-charge resistor or an external spark when plugging in the mains. Of course, without either doing what John advocates (I have one bike like this) or using a pre-charge resistor (I have another like this), there is still a spark. It is just occurring inside the breaker and not in a 4 mm bullet connector.
It could depend on people's experience/set-up. Plugging in 72V to a cold controller is a lot different than 36V.
It could depend on people's experience/set-up. Plugging in 72V to a cold controller is a lot different than 36V.
ryan said:
Okay - I pulled a spare Blue Sea 7244 50A breaker off the shelf (similar but different than yours) and tried your experiment - it doesn't trip until dropped about 9". I'm not trying to interpret this test or its utility - just reporting
I guess I would recommend buying another and returning the one with the poorer test results. Or mount the breaker in such an orientation that it will be unlikely to experience the directional forces your test imparts (e.g. on its side or facing up or down).
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