EG4 3K inverter battery cables

[donb108]

I'm working on a small system for my shed; planning to use the Eg4 3000 ehv-48 inverter with an EG4 LifePower4 48V battery. The inverter comes with 6Ft 4 AWG battery cables, which are the same cables Will used on the Mobile Solar Cart video.

If I'm following the sizing guides correctly, the cables should be sized for (3000w / 48v) x 1.25 x 1.25 = 97.66 amps. But 4 AWG cables are 85 amps @ 75degC. The included battery cables seem to be under-sized; what am I missing?

 

[MichaelK]

what am I missing?

The fact that they are cutting corners at every step. It is only one step that you can see on the outside of the box. The other steps they skip are on inside the box.

 

[donb108]

The fact that they are cutting corners at every step

Hmm, I'm not sure why we're derating twice (1.25 x 1.25). Re-reading the guidelines from 'Solar Array OCP.pdf', "the NEC considers 125% of Isc as the max current (Imax)", and "the NEC requires the fuse or breaker to be a minimum of 125% of Imax".

Maybe they're sizing cables for Imax (max current on the cable), rather than the breaker (OCPD). Then (3000w / 48v) x 1.25 = 78.125 amps. In that case, I guess 4 AWG would be OK.

 

[RebelRob]

3000W / 51.2 / .85 =68.9 Amps

 

[Scat]

3000W / 51.2 / .85 =68.9 Amps

I too am looking to size battery cables.
What is .85 from?
Also I too am looking to size a fuse for the battery cables.
Thanks
Scat