ERMCO manufactures a complete product line of expulsion fuses for use in oil filled distribution transformers. Mounting options include installation inside the high voltage pole transformer bushing and installation using a terminal board.

Three types of fuse cartridge elements are available:

• CURRENT “FAULT” SENSING fuse
• DUAL SENSING fuse
• DUAL ELEMENT fuse.

The Current “Fault” Sensing Fuse (catalog numbers 9F54MFC—) is sensitive to current only and offers protection to the primary circuit from transformer faults.

To avoid closing on a fault an Isolation Link or a current limiting fuse must be used in series with the Bayonet Fuse. The current limiting fuse is required when the available fault current exceeds the interrupting rating of the Bayonet Fuse.

The Dual Sensing Fuse (catalog numbers 9F54LFC—) is sensitive to both current and oil temperature, thus providing both overload and primary circuit protection.

To avoid closing on a fault an Isolation Link or a current limiting fuse must be used in series with the Bayonet Fuse. The current limiting fuse is required when the available fault current exceeds the interrupting rating of the Bayonet Fuse.

The Dual Element Fuse (catalog numbers 9F54DFC—) sensing the oil temperature, as well as extreme load currents, secondary faults, and transformer faults. The dual element fuse will reduce the heating time in a transformer caused by overloads and extreme temperature conditions.

To avoid closing on a fault an Isolation Link or a current limiting fuse must be used in series with the Bayonet Fuse. The current limiting fuse is required when the available fault current exceeds the interrupting rating of the Bayonet Fuse.

Bayonet Fuse Application Table

Bayonet Fuses Catalog

ISO Link Data Sheet

Fuse Curves of Isolation Links

Bayonet Fuse Curves

9F54MFC

• GES-8224
• GES-8225
• Current “Fault” Sensing Fuse Plot Points

9F54LFC

• GES-8226
• GES-8227
• Dual Sensing Fuse Plot Points

9F54DFC

• GES-8228
• GES-8229
• Dual Element Fuse Plot Points