Electricity: electrical systems and devices – Control circuits for electromagnetic devices – For relays or solenoids
Patent
1979-02-09
1980-10-21
Broome, Harold
Electricity: electrical systems and devices
Control circuits for electromagnetic devices
For relays or solenoids
335174, 335181, H01H 4718
Patent
active
042297753
ABSTRACT:
A tripping device for a circuit breaker combines the functions of a current transformer and trip actuator. The device comprises a core member, and an armature disposed in relationship to the core member to establish first and second magnetic circuits. A primary winding carrying load current of an associated circuit interrupter is coupled to the first magnetic circuit and a secondary winding is coupled to the second magnetic circuit, the secondary winding having a temperature dependent switching resistor connected across its output. The armature is movable between normal and trip positions. Low to moderate overloads cause the resistor to heat and switch to a lower resistance, thereby permitting increased current to flow in the secondary winding. This generates magnetic flux opposing the flux produced by the primary winding to lower the net flux in the second magnetic circuit. Magnetic forces on the armature thereby become unbalanced, allowing the armature to move to the trip position. The switching resistor has a switching characteristic such that an inverse time-current delayed trip operation is provided.
A spring and stop screw are provided to act upon the armature to allow the armature to immediately move to the trip position upon large overcurrent conditions, thereby providing an instantaneous trip capability.
REFERENCES:
patent: 1219512 (1919-01-01), Hewlett
patent: 2552614 (1951-05-01), Baker
patent: 3128417 (1964-04-01), Brown et al.
patent: 3184651 (1965-08-01), Albosta
patent: 3403362 (1968-09-01), Strom
patent: 3534307 (1970-10-01), Spewock et al.
patent: 3585458 (1971-06-01), Yoshimura
patent: 4019097 (1977-04-01), Miller et al.
Broome Harold
Converse, Jr. Robert E.
Westinghouse Electric Corp.
LandOfFree
Circuit breaker magnetic trip device with time delay does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Circuit breaker magnetic trip device with time delay, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Circuit breaker magnetic trip device with time delay will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2026192