DFA 3 from Doepke with and without automatic reclosing
Whether it’s a case of lightning strikes during storms or network switching with regenerative power generation: there are some false alarms that can cause a residual current circuit-breaker to trip. If the system then remains switched off for an extended period, for example because it is unmanned or the trip has not been noticed for some other reason, unnecessary costs might be incurred. This is where the new DFA 3 remote actuator from Doepke comes to the rescue. It restores power after a residual current circuit-breaker has tripped. There are two versions available: a model with automatic reclosing, and one with manual remote reclosing. Existing residual current circuit-breakers can be retrofitted easily thanks to the DFA 3’s simple click-on connection; and with its compact design of just one module width, the DFA 3 also takes up minimal space.
Closing a residual current circuit-breaker does not usually pose a problem for easily accessible systems. It’s a different story for exposed outdoor facilities, such as photovoltaic and wind power plants or charging stations for electric cars. A tripped residual current circuit-breaker can also cause unmanned lifting stations, heat pumps, radio installations and cooling systems to be at a standstill for quite some time. This can result in unnecessary costs for service personnel, or loss of revenue if the power supply is off for an extended period. Doepke, the residual current protection technology specialist, has developed a multi-functional remote actuator for residual current circuit-breakers for just such situations. With the DFA 3 024DC-3 model, which offers three automatic reclosing operations, the remote actuator restores the power automatically 15 seconds after the residual current circuit-breaker trips. A manual inspection of the system on site is only required if the circuit-breaker trips repeatedly when there is an actual system failure. The DFA 3 024DC-0 without automatic reclosing is ideal for applications where automatic reclosing is not required or permitted. With this model, the failure is indicated by a signal output, and the system is switched on again remotely through manual activation.
Keep a close eye on the residual current circuit-breaker
The DFA 3 remote actuator also enables the status of the associated residual current circuit-breaker to be monitored remotely. Through the signal output, it provides information (from data logging) on whether the protective device is active or switched off/tripped. If tripping tends to occur frequently, it may be advisable to have the system inspected on site by an electrician.
Besides the signal output, the DFA 3 also indicates the current status visually using an LED. It emits short tones to indicate on/off switching operations acoustically. An independent voltage source of 24 V DC is required to operate the remote actuator, in order to guarantee the signalling and actuator function.