How to select cable and fuse for the battery system? - Engineering Discussions - IET EngX - IET EngX

How to select cable and fuse for the battery system?

I am trying to select the cable and the fuse protection for the battery system. 

My initial approach was to use the same method I am using for the PV systems.

For example, for this PV panel Isc  is 8.80 A and Imp is 8.28 A. For this example, according to the various PV standards (IEC 60269-6, 62738 and 62548) the fuse is selected based on the short-circuit current:

PV fuses designed according to IEC 62548 standard requirements: 1.5 Isc-modIn ≤ 2.4 Isc-mod

In this example, the 15 A fuse is selected, and since the permitted current-carrying capacity of the cable must be same as or greater than the trigger current of the string fuse, the cable is 4 mm2. Please note this just a simplified example to illustrate the method. 

For batteries, are there any other standards?

How would one proceed in selecting the cable and the fuse and make sure coordination between the components is achieved?

Also, the short circuit is either not listed the datasheets (e.g., 1, 2, 3) or if it is (e.g., 4, 5), it is in kA range for ~ 5 kVA batteries. So the ration between Ibat and Isc-bat is > 100. 

If I use the fuse and the cable sizing based on the PV short circuit method (1.5 Isc-mod ≤ In ≤ 2.4 Isc-mod), this would given me the huge values for In. But then again, I need to be sure the fuse will trip on the battery short circuit and not explode due to high arc if I base my selection on the Ibat values.

Parents Reply Children
No Data