High Voltage Transformer Fuse Sizing

Fuse 3x87a 262a so next standard size of fuse 300a.

High voltage transformer fuse sizing. Medium voltage fuses offer a much wider range of system voltages thereby resulting in a correspondingly large number of fuse voltage ratings. Circuit breaker 6x87a 525a so next standard size of cb 600a. If you need assistance with circuit protection devices such as fuses or breakers or wire sizing please consult a licensed electrical contractor or electrician in your area who will be familiar with state and local codes. The rated voltage of the fuse urf in kv must be greater than or equal to the rated voltage of the system.

Link ratings for single phase individual transformer sizes cooper type d fuse link ratings for three phase individual transformer sizes kva single phase voltage kv 2 4 4 8 7 2 7 62 7 97 12 13 2 13 8 14 4 16 3 19 9 22 9 5 4 1 5 1 1 1. Calculate size of circuit breaker or fuse on primary and secondary side of transformer having following detail transformer details p 1000kva primary voltage vp 11000 volt secondary voltage vs 430 volt transformer impedance 5 transformer connection delta star transformer is in unsupervised condition. Fuse that when melted by a current within its interrupting rating produces arc voltages exceeding the system voltage which in turn forces the current to zero. For questions contact our technical support and engineering services group at 800 tec fuse 800 832 3873.

Low voltage fuses are used to protect the primary and or. Transformers having primary voltage ratings between 34 5 kv and 138 kv with medium voltage 4 16 kv through 34 5 kv secondaries will be covered. High voltage power fuses provide a reliable and economical means of protecting small to medium sized transformers installed in utility and industrial substa tions. The arc voltages are produced by introducing a series of high resistance arcs within the fuse.

Use the fuse size recommended for the largest transformer connected to the lead under consideration. For more specific sizing recommendations refer to tables. Full load current at secondary side 10000000 1 732x11000 525a. Or rating of pri.

Fuse 2 25x525a 1181a so next standard size of fuse 1200a. Selection guide for transformer primary fuses in medium voltage industrial commercial and institutional power systems s c power fuses types sm sml and smd 20 indoor and outdoor distribution 4 16 kv through 34 5 kv. Transformer primary current ip p 1 732xvp transformer primary.