The present invention is provided with: a first contact in a first relay connected to a circuit to be grounded; a resistor which is connected between the first contact and the earth, and which suppresses the flow of electric current to the first contact when the first contact is closed; a second contact in a second relay connected in parallel to the resistor; and an interlocking control means which inhibits opening of the first contact in a closed state when the second contact is opened, and which inhibits closing of the first contact in an open state when the second contact is closed.

A switching element (100) that comprises a switching unit (30), a first and a second coil unit (10, 20) for closing and opening the switching unit (30), wherein the first coil unit (10) comprises a first coil (12) and wherein the second coil unit (20) comprises a second coil (22). According to the invention, the first coil unit (10) comprises a first controllable delay circuit (14) that is connected in series with the first coil (12). The invention further relates to a switching device (200) that comprises a switching element (100) according to the invention. The invention further relates to a first and a second method for the operation of the switching device (200) according to the invention.

A method for operating a switching arrangement of an energy storage system, the energy storage system comprising a plurality of parallelly arranged battery packs and the switching arrangement comprising an associated contactor for each battery pack, the contactors being configured to connect and disconnect the battery packs relative a load by closing and opening, respectively. The method comprises disconnecting the battery packs from the load by means of the contactors such that the battery packs are disconnected in a sequence in which one contactor is opened last and thereby subject to increased disconnection wear, controlling the sequence in which the battery packs are disconnected in such a way that the increased disconnection wear is accounted for and used to distribute contactor wear among the contactors during subsequent disconnections of the battery packs from the load.

A tester for a relay comprises an enclosure, a testing circuit that includes a controller, electronic switch components, a power source, indicator LEDs, a test start switch, a relay selector switch, and five electric leads each connected with one terminal of the relay. With the relay selector switch toggled to indicate the type of relay being tested, with power supplied to each lead, and with the test start switch actuated, the controller sets each lead to ground, in turn, and then count the number of other leads that are grounded as a result. The controller then illuminates the at least one indicator to indicate either the passing relay test or the failed relay test based on the counts measured. Once the leads connected to the relay coil are identified, cyclic testing of the relay can be performed.

The relay safety system provided by the present invention includes a relay, an emergency stop device, a trigger detection circuit, a sticking detection circuit, and a power-off circuit. The emergency stop device is used to generate an emergency stop signal. The trigger detection circuit connects the relay and the emergency stop device, and is used to convert the emergency stop signal into a trigger signal. The sticking detection circuit is connected to the trigger detection circuit and the relay, and is used to detect the sticking signal generated by the relay, and generate a power-off signal according to the trigger signal and the sticking signal. The power-off circuit is connected to the emergency stop device, the relay and the sticking detection circuit, and receives the power-off signal, and disconnects the power of the relay according to the power-off signal.

Systems and methods for contact erosion mitigation are provided. To perform contact erosion mitigation, an order of opening/closing poles and/or contact relays of particular poles is altered, resulting in a sharing of potential arcing conditions amongst the poles/contact relays of these poles.

A relay control apparatus and method for retaining a relay in a closed state even though a system error occurs to reset the processor. Therefore, the relay control apparatus and method prevents an accident caused by the reset of the processor since the operation state of a plurality of relays is maintained even when the processor is reset. In addition, if the operation state of the processor is a reset state even after a predetermined time passes, the operation state of the plurality of relays is changed to a turn-off state, and system resources and energy are prevented from being wasted. In addition, when the operation state of the processor is recovered, the operation state of the plurality of relays may be controlled by the processor.

A closing mechanism controller includes contactor operating logic that generates a software or firmware based closing mechanism command signal. The controller also includes hardware interlock circuitry that generates an interlock signal, the hardware interlock circuity being configured to compare an interlock signal to the software based closing mechanism command signal and to provide an enable signal to the closing mechanism when the interlock signal matches the closing mechanism command signal.

The relay safety system provided by the present invention includes a relay, an emergency stop device, a trigger detection circuit, a sticking detection circuit, and a power-off circuit. The emergency stop device is used to generate an emergency stop signal. The trigger detection circuit connects the relay and the emergency stop device, and is used to convert the emergency stop signal into a trigger signal. The sticking detection circuit is connected to the trigger detection circuit and the relay, and is used to detect the sticking signal generated by the relay, and generate a power-off signal according to the trigger signal and the sticking signal. The power-off circuit is connected to the emergency stop device, the relay and the sticking detection circuit, and receives the power-off signal, and disconnects the power of the relay according to the power-off signal.

A control device for power supply time of timers comprises an alternative current (AC) power source input module, a direct current (DC) power source supply module, an AC power source output module electrically connected to a load end, a relay, a central control module, a relay driver circuit, a day/night detecting module, a power supply time backward display light set, a power supply time forward display light set, a power supply time backward selection control button and a power supply time forward selection control button. Herein, by pressing the power supply time backward selection control button or the power supply time forward selection control button, one of the power supply time backward display lights or the power supply time forward display lights can be turned on such that the central control module can, based on the sunset time of the previous day as well as the configured power supply backward setting time or power supply forward setting time, postpone or advance the power supply time for the load end in the next day, and then record the sunset time of the next day so as to control the power supply time for the load end in the further next day.