Derating values when using SITOR fuses according to UL constraints

The following table shows the permissible load currents of SITOR semiconductor fuses for installation in 3KF SITOR according to UL constraints. The specified values apply to a 3KF mounted in accordance with the test conditions of UL 508 / UL 60947-4-1 (installation in an enclosure) and with connected insulated cables, cross section corresponding to the rated operational current of the 3KF switch disconnector. The specified values apply to use in enclosures that are larger or equal in size to the specified enclosures.

Further derating is necessary if a combination of 3KF and SITOR fuses is used under different conditions that impair heat dissipation.