TESTING ALI EXPRESS DC BREAKERS

I have been on a quest for some high current DC breakers for my solar project. While there are solar specific breakers out there, they cost a fortune so my search ended up sending me to Ali Express where i found some 125A 250V DC breakers direct from the manufacturer. First impressions are that they might actually be capable of their ratings and at $12 each shipped i cant complain about the price.

Link to breaker on Ali Express

Link to the Genuine marine breakers i am currently using

[disonlinux]

It's not much of a test without verifying that it does trip at the rated current.

[Doctorbasss]

Testing breaker is normally not like testing a switch... you must test the trip amp too.

[vaguedirector_]

(1:00) Thermal circuit breakers are heated/tripped by current (P=I^2*R), system voltage does not have any effect at all on the trip current. The voltage rating of a breaker is do do with arc suppression, if you run a 12V breaker at 48v it may be unable to survive the arc upon disconnecting and blow up.

[coil]

Have you shut that breaker off under load to see if it will arc over or not? Its a good test to try what happens if it trips, arcs over and catches on fire ? My worry with most dc breakers is can they quench the arc

[supernovatiger]

Did you test disconnect under fully load ?!! I think it will fireup

[johnle]

Any updates 3 years later on these tomzens

[dasimpson]

red is for danger live green is for safe

[nielsdaemen]

You need to test if it actually breaks at 120+ A Without catching on fire...

[ntal]

Its not the breaker being AC its the terminal blocks(wire gauge) can't fit larger wires . So you end up at 63 amp.

[SkypowerwithKarl]

⚠️❌‼️ Warning! DC breakers shown (white with blue toggle) are polarized. Look closely and you can see the +&- signs. The polarization at the bottom of the breaker would of course be same as the top(straight through). They have an arc channel. To feed it backwards can cause damage or fire it you are feeding high voltage though it. They have those breakers up to 1000 volts on Amazon. DC high voltage can draw amazing arcs and can kill you. Dangerous as hell. The black rv/marine versions are only good up to 48 (56) volt systems. Use a charging resistor to load the capacitors in an inverter or charger to make them last. Use name brand of the rv type or you risk damage.

[chrislu]

Steven have tested the breaker and see how long does it take to trip the breaker say like at 120% of rated current?

[youMarv]

I would love to see them switch off with a current around 80A drawing. So we could see if the arc got extinguish fast enough. Also your Cables look kind of small. What mm² is this? How much can the Breaker handle? I want to use 2x25mm² in it.

[mtay]

You called that testing? I was expecting the breaker to trip at +/- 125A but none.

[lyrapkfvl]

I bought these on aliexpress.
2x 2P 100A DC600V TOMZN STILL WORKING
2X 2P 125A DC600V TOMZN FAULT AFTER 6 MONTH (1 tripe at 90A)
2X 4P 125A DC1000V EARU 1POLE FAULT AFTER 3 MONTH
1X 2P 150A DC240V TAIXI STILL WORKING
max 58.8V 200A test

[surfreadjumpsleep]

maybe test it actually breaking the circuit?

[jamaicanarchitect]

to properly test the DC capability you have to test with high voltage (above 350v) ) and the fault will occur when you try to turn off the breaker, the arc from DC is harder to extinguish inside a breaker, a AC breaker will catch on fire

[UKsystems]

How did it come direct from the manufacturers website if it is aliexpress

[SHADOW-bgmm]

My plan was to use it as a double pole disconnect, off, on switch for solar panels, with a Anl fuse, i dont trust the marine dc breakers, unless i pay for the premium brands, im sure some doing the same, I have to test it and see if it works too

[ivaylomanolov]

Hi, is this circuit breaker enough to protect Lifepo4 batteries or should it be combined with fuses?

[hendersonsobers]

How has this breaker been working out for you? Good job on the video.