- Electrical Contractor
Fuses as in opens, or becomes one?Just to put things into perspective for those reading:
10 gauge copper wire fuses at 8900 amps of current in 32 milli seconds (this would trip a 30 amp breaker instantly (and larger handle ratings on IM) before fusing can take place) where as that same 10 gauge wire fuses at 333 amps in 10 seconds.
Increasing time results in a steep decrease in a conductor's ability to carry short circuit current.
Ideally the final temprature of the EGC after the breaker opens should not exceed 150*C for THHN/THWN-2 installations and 250*C for XHHW (XLPE) conductor.