I thought I did a beautiful installation. It worked!!! But then the 12v 300 amp breaker keeps tripping. It gets warm first. Sometimes the hum of the box stops, then it retries to start.
The setup is a 300AH lithium battery (LiTime) that has worked well up until now. Its wired with 4/0 cables from the battery (through the circuit breaker on the positive side)- they were bought premade (Spartan Power- each 4’, plus a 1 foot section connecting the breaker to the positive. 10/3 Ancor on the 110 side.
I have a Smart Dongle bluetooth connection, plus the USB MK3.
There is no connection (that is, infinite resistance) when tested with my multimeter across the positive and negative 12v cables, so I don’t see how a normal short could exist.
I replaced the 300amp circuit breaker thinking it might be defective, but the same thing happens.
I set the AC input current limit to 13.4 amps. Right now it says ‘bulk charge’ of 71A, 86% charged. When I first hooked it up, to a bit depleted battery it started at 80A them slowly went down to almost nothing, which is what I think it should do.
You give no details about the DC breaker, some of these are very poor quality, especially the thermal type. If it is a thermal type and your terminals are not torqued correctly this can cause additional heat causing tripping at low current. The Victron manual says to install a fuse, simple, reliable, rugged and well proven. Use a quality manual isolation switch from a reputable manufacturer with the fuse if you need to isolate the dc.
It is an ‘amazon’ fuse… I did think there could be a problem with it, so I bought a different one, wired it in today and bang- off it goes. Makes a bit of a buzzing noise and gets warm before it does go.
I’m a bit reluctant to wire in a fuse at the moment- just because I strongly suspect it will blow (as the circuit breakers do), then its more of a pain to get a new one…
The initial breaker- I’d post the amazon link, but its amazon.ca Its described as BULVACK 300 Amp Marine Circuit Breaker for Boat Trolling with Manual Reset, Water Proof, 12V- 48V DC
The one I installed today is a Jeemiter 300 Amp Circuit Breaker with Manual Reset
There are youtube videos of this type of breaker that claim to be 300A disconnecting at 100A. They are a waste of money and break at the wrong current. I seriously doubt you have a short, you just have cheap and unreliable breakers. Install a proper Mega fuse rated at 300A per the Victron instructions.
I did not watch the whole video, I have now watched a bit more and see it was disconnecting at 80A. I know they are bad but I had not realised how bad. Hope you get sorted OK and that you do not need to be concerned about a fault in your wiiring.
Just a followup- you guys were 100% correct. I put in a proper fuse 2 days ago, been running it since without problems. I CANNOT believe amazon was selling such crap. Anyways, they’ve been returned and refunded (In Canada now, you take the stuff in to Staples with minimal packaging, show them the bar code on your phone, they package it, and you have it refunded before you leave the store- good thing. There were 4 items this time)