I know this is a silly question but I cannot find ant data indicated it will not. The HV connector rated at 300A @ 85C and it is a 600A fuse, I cannot find a connector with a higher current rating.

The contentious current is 100A, however if

  1. contentious current is 600A at 50C, is my connector under spec'ed?
  2. if peak current is 1200 for less than 5s, is my connector under spec'ed?
  3. if there is dead short (400v), will the connector fail before the fuse does?



Fuse: https://www.littelfuse.com/~/media/electrical/datasheets/fuses/semiconductor-fuses/l70qs_high_speed_fuse_datasheet.pdf

Connector derating curve: enter image description here

  • \$\begingroup\$ Your connector is underspecced, yes. You're using it at almost double the rated current. \$\endgroup\$
    – Hearth
    Oct 26, 2018 at 22:02

2 Answers 2


Yes, yes, and almost certainly.

Unless there is a specifically noted "peak current" spec that is higher than the "rated current" spec, you have to assume that the peak current cannot the maximum rated current. 5 seconds is long enough that it can generally be considered "continuous" anyway.

It seems pretty clear that pushing 600A (let alone 1200A) through a connector rated for 300A is way out of spec. Of course, being out of spec doesn't guarantee that the connector will fail... but I wouldn't count on it working.

Also, take a look at the opening time curves on your fuse. Your 600A fuse will take 10 seconds to blow at about 2400 (!!!!) amps. This is typical - fuses never have nice, sharp cutoffs - there is a large range between their rated (continuous) current and the current that opens them quickly.

I don't know how much current your supply is capable of, but if a short circuit produces anywhere between 350A and 2400A, I'd bet on the connector blowing long before the fuse. If your short circuit produces upwards of 4000A, your fuse will blow in around 10mS - but then, your connector will blow much faster as well, so the connector could very easily still blow first.


If, in that 5 seconds, you can prevent melting the solder, then you probably OK.

Do your thick wires (wires the size of battery cables in a CAR, right?) have enough thermal mass to keep both the wires and the CONNECTOR PINS below the temperature of melting solder?

Caveat----why not be cautious and avoid fires, avoid intermittents later?


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