Compact high voltage power fuse and methods of manufacture

A compact, full-range power fuse comprising:

• a housing including opposed first and second ends;
• first and second end plates coupled to the respective first and second ends;
• first and second terminals extending from the respective first and second end plates;
• a full-range current limiting fuse element assembly defined by a combination of fuse elements entirely enclosed in the housing and respectively having a first melting mechanism uniquely responding to a high current or short circuit fault and a second melting mechanism uniquely responding to a low overcurrent or overload fault current condition, each of the first and second melting mechanisms extending internally in the housing and electrically connected in parallel to one another via direct attachment to the first end and the second end plate, wherein a consecutive opening of the first melting mechanism and the second melting mechanism in response to each of a predetermined high current fault condition and a predetermined low current fault condition confers full-range time-current operation in an operating electrical power system generating an unpredictable series of positive and negative current pulses of varying magnitude;
• a filler surrounding the full-range current limiting fuse element assembly in the housing, wherein the filler is mechanically bonded to the full-range fuse element assembly to reduce thermal mechanical stress and mitigate load current cycling fatigue from the unpredictable series of positive and negative current pulses of varying magnitude;
• and
• wherein at least the first end plate and the first terminal are defined by a single piece fabrication.

A power fuse comprising:

• a housing;
• a single combination of a short circuit fuse element and an overload fuse element enclosed in the housing, wherein the overload fuse element is distinct from the short circuit fuse element, the short circuit fuse element and the overload fuse element respectively being connected in electrical parallel to one another inside the housing and producing a current limiting effect protecting an operating electrical power system generating an unpredictable series of positive and negative current pulses of varying magnitude;
• the short circuit fuse element being specifically responsive to melt in a high current or short circuit fault in the operating electrical power system that initially will not affect the overload fuse element;
• the overload fuse element being specifically responsive to melt in a low overcurrent or overload fault current condition in the operating electrical power system that initially will not affect the short circuit fuse element;
• wherein a combined opening of the short circuit fuse element and the overload fuse element provides a full-range time-current limiting operation to a protected circuit in the operating electrical power system in response to both of the low current fault condition and the high current fault condition;
• and
• a filler surrounding the short circuit fuse element and the overload fuse element in the housing, wherein the filler is mechanically bonded to the short circuit fuse element and to the overload fuse element to reduce thermal mechanical stress and mitigating load current cycling fatigue from the unpredictable series of positive and negative current pulses of varying magnitude;
• wherein the housing has a compact axial length of about 1.5 inches to about 3 inches and wherein the power fuse has a voltage rating of at least 500 VDC and a current rating of at least 150 A.