On-site interventions (Site Infrastructure - Electricity)dandrea - 11:49 Tuesday 06 April 2021 (51325)
Print this reportENEL network failure 03-04-2021Last night (03-April-2021) starting from about 21:20, the ENEL network started to give problems with network holes and spikes, then at 21:30 it stopped and the emergency generators started on the whole site. I received the telephone alarms from my monitoring system so at 22:08 I called the guard, to understand if the generators were really on but he could not explain to me what was happening, so I decided to go to the site. I arrived at the site at about 10:30 pm and as soon as I arrived the generators stopped, so they ran for about an hour, so I decided to check the electrical systems. I checked the generators and they all worked regularly, so it was also for the UPS which kept us safe from all the mains holes that occurred before the generators intervened. I then did a check on the transformer cabins, where everything was regular, but I could see that the output voltage from the transformers was unusually below our ordinary values, not in a worrying way but the phase-to-phase voltage was 395 V against the 410 V we usually have, for me it was a signal to make me understand that on the 15 KV network there was something strange. I went to the office and after doing more detailed checks of the parameters on the monitoring network, these values were confirmed by all the instruments. I called the ENEL breakdown service, which confirmed the presence of a fault in our area and that they were repairing it, then I pointed out the abnormal voltage values and the operator recorded my report and I left mine. telephone number for further technical information. My impression is that we are provisionally powered by an emergency ENEL network with network values different from the one that usually feeds us, or ENEL has a fault on another line and has temporarily shifted the load of that line to the one it feeds. us too, sending it into overload with consequent decay of the network parameters. Confirmation of my impressions arrived at 02:00 am on April 4th, when I was called by the ENEL technical service who confirmed that we were powered by an emergency power supply configuration, as they had a fault on the line to which we are connected normally. They told me they would fix the fault today (April 4th), so I assume we should be back on our regular network by evening.
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dandrea - 11:50 Tuesday 06 April 2021 (51326)
Print this reportI went back to the site to do some checks, as as announced last night, the ENEL power supply network is not within the ordinary parameters, and I also received a report from Davide Soldani that some thermal switches of some pumps have intervened and stopped the motors. Unfortunately, the first failure we suffered last night was not caused by a net power outage, but manifested itself with a progressive decay of the network parameters which lasted a few seconds, and this may have resulted in suffering all the devices powered by the IPS network, such as an overcurrent on the motors that causes the intervention of the thermal devices reported by Davide Soldani, and in any case also in subsequent moments when the power supply network has low voltage values and current distortions, untimely trips can occur. While on the UPS network, at least from all the visual checks that I have been able to do on the site and on my monitoring system, it does not show anomalies, but on this I expect more precise reports from the punctual checks made by the people who manage the subsystems powered by the UPS. I was able to verify that we are still powered by the "provisional" ENEL network, this means network values that are not good with voltages below normal and significant current distortions, so the devices on the IPS network do not work in optimal conditions so the situation must be monitored, trusting that ENEL can repair the fault within the day.