Output power
- 24 power channels of 230 V each (8 outputs per phase)
- Max. 1 000 W switching capacity per output
- Max. 7 360 W switching capacity per phase
- Power triacs with zero crossover switching
- Protection of triacs and opto-triacs against overvoltages by Transil diodes
Forced ventilation
Depending on the switching capacity and ambient temperature, the power output module may have to be forced ventilated. An LM724 fan module is available as an option for this purpose. For detailed informationsee Manual.
Temperature monitoring
There is an NTC thermistor on the heat sink for monitoring its temperature. This temperature-dependent resistor outputs a signal to the S7-300 at 92 °C ± 3 °C. A second switching threshold at 100 °C ± 3 °C switches off the power outputs of the module.
Fuses
Each channel of the LA 724I power output module has an externally-accessible 5 A fuse to protect the power triac and a 32 A fuse per phase to limit the phase current.
Diagnostics facilities
Diagnostics functions are provided as standard to detect the following faults:
- Internal fuse defective or triac at high-resistance
- Triac failed
- External fault such as blown fuse, heat emitter or cable breakage
If several heat emitters are connected to one output in parallel, failure of an individual heat emitter is detected by means of extended diagnostics.