Switch-off characteristics
The EP92x4 EtherCAT Box selectively protects all connected 24 VDC load circuits. This is done via various electronic circuits, additionally protected by a 7 A micro-fuse.
Selective switch-off means that the load circuits are individually monitored and if a channel is exceeded, only that channel is switched off.
This ensures the function of the remaining consumers connected to the higher-level power supply unit.
General functional principle
The EP92x4 EtherCAT Box monitors the current for each of the 8 output channels. 4 x Us, 4 x Up. Switching off takes place depending on the selected nominal current and tripping characteristic.
Superordinate to all is the hardware switch-off, which responds if
- 7 A is reached for 50 ms
- there is a short-circuit for 50 ms
- the capacitive load and thus the start-up current of the connected devices is too high
Due to the intelligent current limitation an output current exceeding 7 A is not possible under operating conditions. The additionally installed 7 A micro fuse thus blows only if the upstream electronic switch-off is already defective.
The nominal current can be set individually for each output channel Us and Up between 1 A and 4 A (in mA) or 3 A in the case of EtherCAT P devices.
All set characteristics are referenced to the set nominal current. The following table shows the response time of the monitoring in relation to the nominal current and characteristic.
Nominal current | Very fast acting | Fast acting | Slow acting | Time delay |
|---|---|---|---|---|
100 % | 1 h | - | - | - |
110 % | 1 h | 4 h | - | - |
120 % | 7 min | 4 h | - | - |
150 % | 30 s | 30 min | 1 h | 4 h |
210 % | 500 ms | 20 s | 20 s | 100 s |
275 % | 500 ms | 1 s | 20 s | 10 s |
300 % | 20 ms | 100 ms | 1 s | 3 s |
If overcurrent (≥ nominal current) is detected and it is foreseeable that the current monitoring will trip if conditions remain unchanged, then a warning is given both in the process data and in form of a flashing LED. An output switch-off due to overcurrent is indicated by a red LED.
If one of the outputs was switched off due to a diagnosis, it must be reactivated by an active RESET.
 | Restart after Power OFF/ON If an output was switched off due to an error, then an active reset by the RESET contact (if existent) or the fieldbus is necessary. Switching off and on again is not sufficient! To protect the circuitry, a RESET can take place maximally every 20 seconds. |
Switch-on can take place either by EtherCAT or by 24 V on the RESET contact (if existent). To protect the circuitry, a RESET can take place maximally every 20 seconds. Faster successive edges are ignored.
Switch-on delay of load circuits 1 to 4
Here is a table of the startup times, adjustable in the CoE object 0xF80E:11
Description | Switch-on delay |
|---|---|
Fast | 10 ms |
Moderate | 100 ms |
Slow | 200 ms |