Patent ID: 11892483
Assignee: ISABELLENHUETTE HEUSLER GMBH & CO. KG
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 29:
30. A current measuring resistor for measuring an electric current, comprising:
a) a first connection part comprising a conductor material for introducing the electric current into the current measuring resistor,
b) a second connection part comprising a conductor material for conducting the electric current out of the current measuring resistor, and
c) a resistor element comprising a low-resistance resistance material, the resistor element being arranged in a direction of current flow between the first connection part and the second connection part and being joined to the first and second connection parts so that the electric current to be measured flows through the resistor element during operation and produces a voltage drop across the resistor element,
wherein:
d) the first connection part, the second connection part and the resistor element each have a substantially round cross-section in a sectional plane at right angles to the direction of flow of the electric current,
e) the conductor material is copper or a copper alloy,
f) the conductor material of the first and second connection parts has a lower specific electrical resistance than the resistance material of the resistor element,
g) the resistance material of the resistor element is a copper-manganese-nickel alloy,
h) the resistance material of the resistor element has a resistivity of less than 1000 μSΩ cm (microohm·centimeter),
i) the conductor material has a specific electrical resistance of less than 20 μΩcm,
j) at least one of the resistor element, the first connection part and the second connection part are of solid construction without cavities,
k) the first and second connection parts each have an axially extending longitudinal groove in their lateral surface, which groove starts from an end face of the first and second connection parts,
l) the first and second connection parts each have in their lateral surface at least one radially extending blind bore for housing assembly,
m) the first and second connection parts each have in their end face an axially running blind bore,
n) the first and second connection parts each have in their lateral surface a circumferential annular groove with a polygonal cross section which serves as a manufacturing aid,
o) an outer diameter of the round resistor element is at least 6 cm (centimeter),
p) an outer diameter of the round connection parts is at least 2 cm,
q) the current measuring resistor has an axial length in the direction of current flow of at least 10 cm,
r) the resistor element has an axial length in the direction of current flow of at least 1 cm,
s) the first and second connection parts each have an axial length in the direction of current flow of at least 10 cm,
t) the first and second connection parts each have a mass of at least 1 kg (kilogram),
u) the resistor element has a mass of at least 0.5 kg,
v) the current measuring resistor has a continuous current carrying capacity of at least 1 kA (kiloampere),
w) the current measuring resistor is suitable for a voltage level of at least 1 kV (kilovolt) for alternating current, and
x) at least one of the first connection part, the second connection part and the resistor element each have a polygonal cross-section in a sectional plane at right angles to the direction of flow of the electric current, with at least 12 corners to form the substantially round cross-section.