•
•
•
Minimum pro-
spective SC cur-
rent of the grid
[kA]
Maximum fuse
rating F1 [A]
Minimum volt-
age rating [V]
5.9.3 Recommended Fuse Ratings for UL Installation
The fuses and MCCBs contained in the enclosed drive are suitable for both short circuit and branch circuit protection. Use only these
fuses.
UL Approval is valid for maximum input voltage of 600 V. Per UL508A, the short-circuit current rating (SCCR) is as follows:
Enclosed drives with a fusible disconnect or fusible disconnect and contactor option have 65 kA SCCR at the rated voltage.
Enclosed drives with single switchgear (mains contactor only or non-fusible disconnect only option) have a 5 kA SCCR, but can
reach 65 kA if the recommended Class fuses are used upstream.
Enclosed drives with the MCCB option have a 65 kA interrupting rating for 380–480 V, and a 50 kA interrupting rating for525–
690 V.
The table values are calculated using correction factors for a 40 °C (104 °F) ambient operating condition and using cables with a
minimum insulation rating of 90 °C (194 °F).
Table 67: Recommended Fuse Ratings for UL Installation, 380–480 V
Maximum fuse rat-
ing F1 [A]
Minimum voltage
rating [V]
Table 68: Recommended Fuse Ratings for UL Installation, 525–600 V
Maximum fuse rat-
ing F1 [A]
Minimum voltage
rating [V]
AQ357954340588en-000201 / 130R0881 | 91Danfoss A/S © 2020.09
Electrical Installation
VLT® Refrigeration Drive FC 103
Operating Guide