Originally Posted by Toys_with_time
Have just finished setting up my Lithium
batteries with a 60 amp DC
fed from solar
/ shore power
house bank. Batteries showing charge rate of max 58 amps but keeps blowing fuses
. I started with 70 amp trip fuse then a 70 amp ANL then a 100amp ANL but all blow even though they are rated higher than the current
that is flowing.
Anyone have any suggestions?
There are a few possible explanations for a fuse blowing at currents below its rating. One is elevated environment
temperatures: the hotter the environment
, the lower the current the fuse blows. This elevated temperature can come from external sources (e.g. battery
charger nearby) or from internal sources (bad connection at the fuse). Pulsed energy delivery
, such as from alternators and some chargers, also leads to the fuse blowing at lower average current as for the fuse the average square of current
matters (in a resistor, the square of current is proportional to the produced heat). Would it be possible to measure the fuse terminal temperatures?
That aside, a fuse is normally sized such that it protects the wire, and the device current is not taken into account. Ampacity charts
) might be useful.