A friend of mine purchased a Mecer (SOL-I-AX-5M4) inverter in November and had it installed. This is the new Axpert inverter range with the large color changing light depending what mode it is in. It is not a grid-tie inverter. Within 2 weeks after installation it caught alight a few minutes into load shedding. Mercer identified the fault as a "Blown AC Output" from a power surge??? This 5kva unit supplied power to a TV, DSTV box and 3 lamps so he enquired how this was possible, but the evidence showed the blown AC Output. Mercer provided a replacement unit which was installed the same way and 16 days later on Boxing day, 3 minutes into load shedding it went up in smoke again. This time my friend was in the kitchen and noticed that plugs that are not on UPS output were still ON.
Very strange to see two units fail in the same way. He has had the electrician out and checked everything and had a second person check and all is wired correctly.
It is almost like the inverter was pushing power back to the DB and the neighborhood for that matter via the AC input side.
I have the older Axpert 5kVA RCT unit from 2015 and at this time managed to download a service manual for my unit. See attached document. This has a block diagram figure 2.1 which seems to show a safety relay and an inverter relay. I assume there is some interlocking to make sure both are not energized at the same time. This is not to say the new model Axpert units have the same block diagram.
I am just wondering if there is an operating mode (Power saving mode) say when the load is very low that the inverter relay is OFF and the safety relay is ON.........and then load shedding starts and the inverter relay kicks in before the safety (Bypass) relay has had time to de-energize thus creating a mains path from the inverter output relay to the input. Then I am guessing that the UPS input now has voltage on the input and re-energizes the safety relay holding it ON. The current would be high and keep the inverter Relay ON. (Assuming it is looking at the current passing through the inverter and not the output relay.
This would explain not tripping the output breaker on the inverter as this is after the safety relay connection point. Will the circuit breaker on the DB board supplying the inverter fail to trip as the current is now in the opposite direction?
Has anybody heard of there being problems with these new model Axpert units?
Any other ideas or theories?
Very strange to see two units fail in the same way. He has had the electrician out and checked everything and had a second person check and all is wired correctly.
It is almost like the inverter was pushing power back to the DB and the neighborhood for that matter via the AC input side.
I have the older Axpert 5kVA RCT unit from 2015 and at this time managed to download a service manual for my unit. See attached document. This has a block diagram figure 2.1 which seems to show a safety relay and an inverter relay. I assume there is some interlocking to make sure both are not energized at the same time. This is not to say the new model Axpert units have the same block diagram.
I am just wondering if there is an operating mode (Power saving mode) say when the load is very low that the inverter relay is OFF and the safety relay is ON.........and then load shedding starts and the inverter relay kicks in before the safety (Bypass) relay has had time to de-energize thus creating a mains path from the inverter output relay to the input. Then I am guessing that the UPS input now has voltage on the input and re-energizes the safety relay holding it ON. The current would be high and keep the inverter Relay ON. (Assuming it is looking at the current passing through the inverter and not the output relay.
This would explain not tripping the output breaker on the inverter as this is after the safety relay connection point. Will the circuit breaker on the DB board supplying the inverter fail to trip as the current is now in the opposite direction?
Has anybody heard of there being problems with these new model Axpert units?
Any other ideas or theories?
