...
| IEC ampacity (A/m2) | 1.3 | cyclic load | 1.3 | alt(min) | 2500 | alt(max) | 2600 | Kx | 0.8 | ||||||||
| current | Kt(min) (T=60C) | Kt(max) (T=60C) | Kt(max) (T=45C) | Wire diameter | Cross sectional area | 100% cable area | % cable used | Ke | Kv | Ka(min) | Ka(max) | I(rating) max | I rating min | wire current rating | maxium fuse | ||
| Battery fuse | 84.66392931 | 0.845 | 0.9 | 6.15 | 29.70572204 | 65.12609947 | 0.456126227 | 0.95 | 1 | 0.975 | 0.97 | 165.0368992 | 144.8198791 | 255 | 191.25 | EXRAD-XLX-4X | |
| Charger fuse | 21.82539683 | 0.9 | 0.9 | 0.95 | 2.58826 | 5.261452847 | 16.78876679 | 0.313391264 | 0.91 | 1 | 0.975 | 0.97 | 42.07710975 | 38.9739229 | 5573 | 4154.2575 | Awg 108 |
| Motor fuse 1 | 40.21976077 | 0.845 | 0.9 | 4.95 | 19.2442185 | 30.93827752 | 0.622019713 | 0.95 | 1 | 0.975 | 0.97 | 78.40109312 | 68.79695922 | 155 | 116.25 | EXRAD-XLX-6X | |
| Motor fuse 2 | 40.21976077 | 0.845 | 0.9 | 4.95 | 19.2442185 | 30.93827752 | 0.622019713 | 0.95 | 1 | 0.975 | 0.97 | 78.40109312 | 68.79695922 | 155 | 116.25 | EXRAD-XLX-6X | |
| Solar fuse | 9.055479138 | 0.845 | 0.9 | 1.62814 | 2.081964757 | 6.965753183 | 0.298885806 | 0.9 | 1 | 0.975 | 0.97 | 18.63267312 | 16.35017067 | 32 | 24 | Awg 14 | |
| Pre-charger fuse | 2.1 | 0.845 | 0.9 | 1.02362 | 0.82293855 | 1.615384615 | 0.50943815 | 0.95 | 1 | 0.975 | 0.97 | 4.093567251 | 3.592105263 | 16 | 12 | Awg 18 | |
| DC DC fuse | 2.124407764 | 0.845 | 0.9 | 1.02362 | 0.82293855 | 1.634159818 | 0.503585109 | 0.95 | 1 | 0.975 | 0.97 | 4.141145739 | 3.633855386 | 16 | 12 | Awg 18 |
...
| Fuse | current rating | |
| battery fuse | XEV25-175 | 175 |
| Charger fuse | XEV10-40 (not ready)4050 | 50 |
| Motor fuse 1 | XEV20-80 | 80 |
| Motor fuse 2 | XEV20-80 | 80 |
| Solar fuse | XEV10-20 | 20 |
| Pre-charger fuse | XEV10-5 | 5 |
| DC DC fuse | XEV10-5 | 5 |
For the lower-current fuses (Solar, Pre-charger, DC-DC), we will be using the axial bolt-on type.
Alternate Sources for fuses (since COVID happened and Eaton was not going to sponsor for a while)
| View file | ||||
|---|---|---|---|---|
|
Note On Interrupting Rating:
Fuses on our HV system should be able to project against a short circuit condition on the cables they are connected to. So what's the short circuit current?
The max current available from our batteries will be at their highest voltage, since a short circuit is just a resistive load. Maximum condition calculations will assume that the external short is 0mOhm, and the only thing limiting the current is the battery's internal resistance. This is a reasonable estimation as it will ensure an adequate safety factor for our fuses. Since our modules are in series, we only need to do the calculation for 1 module.
Voltage: 4.2V
Internal Impedance (using AC since a short circuit is a transient event, and AC IR is lower than DC IR typically): 25mOhm (ish - rough value of what was observed)
Short circuit current per cell (Iscc) = 4.2/0.025 = 168A
Short circuit current per module = 168A * 25 cells = 4200A = 4.2kA.
So all of our fuses must be rated to break a minimum of around 4.2kA.