US 12,224,577 B2
Apparatus for electrical protection
Walter Alex Planegger, Eindhoven (NL); and Robi Rek, Eindhoven (NL)
Assigned to KONINKLIJKE PHILIPS N.V., Eindhoven (NL)
Appl. No. 17/783,135
Filed by KONINKLIJKE PHILIPS N.V., Eindhoven (NL)
PCT Filed Nov. 25, 2020, PCT No. PCT/EP2020/083268
§ 371(c)(1), (2) Date Jun. 7, 2022,
PCT Pub. No. WO2021/110496, PCT Pub. Date Jun. 10, 2021.
Claims priority of application No. 19213245 (EP), filed on Dec. 3, 2019.
Prior Publication US 2023/0352929 A1, Nov. 2, 2023
Int. Cl. H02H 7/085 (2006.01)
CPC H02H 7/0851 (2013.01) 7 Claims
OG exemplary drawing
 
1. An apparatus for providing electrical protection at a device comprising a motor unit, the apparatus comprising:
a first fuse connected to the motor unit, the first fuse having a first breaking capacity, a first set of time-current characteristics, and a first rating;
a second fuse connected to the first fuse and the motor unit, the second fuse having a second breaking capacity, a second set of time-current characteristics, and a second rating, wherein the second set of time-current characteristics is different from the first set of time-current characteristics and the second rating is different from the first rating; and
a switch, wherein the switch is connected in series with both the first fuse and the second fuse,
wherein the first fuse and the second fuse are connected in series,
wherein a value of the first breaking capacity of the first fuse is set such that at a high overload current fault condition, the first fuse acts to interrupt current before the second fuse, and
wherein a value of the second set of time-current characteristics of the second fuse is set such that at a locked rotor condition of the motor unit, the second fuse acts to interrupt current before the motor unit reaches a maximum winding temperature.