Elevator testing system
AssigneeKone Corporation
InventorsNils-Robert Roschier, Olof Ahlskog
Life of this patent
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Abstract
The invention concerns a method and a system for ensuring the operation of the safety circuit of an elevator or escalator, said safety circuit containing safety contacts (10, 12, 14) connected in series with a contactor (16). In the method, the largest bypass current coming to the contactor in a fault situation is defined, a testing device (202) is connected in series with the safety circuit, said testing device containing at least one resistor (26), which is used to produce a desired test current that is larger than the largest bypass current, and the neutral point (18) of the safety circuit is shifted if the contactor (16) remains energized by the aforesaid test current.
Claims8
A method for ensuring the operation of the safety circuit of an elevator or escalator, said safety circuit containing safety contacts (10,12,14) connected in series with a contactor (16),
- characterized in that the method comprises the steps of:
- defining the largest bypass current coming to the contactor in a fault situation;
- connecting a testing device in series with the safety circuit, said testing device containing at least one resistor, which is used to produce a desired test current that is larger than the largest bypass current;
- and
- shifting the neutral point (18) of the safety circuit if the contactor remains energized by the aforesaid test current.
A system for ensuring the operation of the safety circuit of an elevator or escalator, said safety circuit comprising safety contacts (10,12,14) connected in series with a contactor (16),
- characterized in that the system further comprises:
- a testing device (202) connected in series with the safety circuit and containing at least one resistor (26), which is used to produce a desired test current to the contactor (16), said test current being larger than the largest current coming to the contactor in a fault situation;
- and
- means for shifting the neutral point (18) of the safety circuit in a fault situation where the contactor remains energized by the aforesaid test current.
Dependencies are inferred from the claim text.