ACS800-87LC RMIO always Ready, when converter is not!!
I hope you are doing fine,
we have a wind turbine installed 2.5 MW using a ACS800-87LC Converter, we had a sudden pressure drop in the cooling water, and the RMIO is detecting alert but not giving any decision to the turbine controller to stop via output terminals, and kept the converter connected to the grid, hence destroying 3 INU modules, and 2 Contactor AF2050, and 1 Main CB, we replaced everything mentioned before, we also replaced the INU A41 and ISU A51 RMIOs, also we changed the APBU, with brand new ones, but still the converter is giving ready!!! i have the Fuses out, the cooling water not connected! and it is giving ready! and the turbine is resetting without any fault!! It is very weird.
we turned off all power on the converter (main CB etc..) and just connected the 24V to the RMIO, it still gives ready! we removed some of optical fiber cables from INU and ISU, and it is detecting error, but not de-energizing the emergency output relay on the RMIO “the internal LEDs which responsible for the readiness of the RMIO are still green in emergency and ready situation” ,it is energizing the emergency output relay only when we press the emergency button manually from the control cabinet of the wind turbine, and once we manually close the CB from the converter cabin, the RMIO still gives ready!
on both the Turbine Control Cabin, and ABB DRIVEWINDOW from a separate PC, we are getting ready signal.
we have also disconnected the turbine control system from the converter, and connected it directly to the PC, it still gives ready!
we stopped the turbine to know why this is happening! can you please assist us!
does this RMIO have a specific parameter that keeps it ready all the time! or what? all our engineers here are not coming to a solution!
Noting that this turbine has been in operation for 1 year now and generated more than 13 million Kwh. This case has happened on 13 th Sept.
I hope I can get your reply soon.
I am very sorry for the inconveniences you have described, IMHO I suggest you, instead of changing inverter parts, to quickly contact the ABB Service in your area and get help from them.
Any suggestions I could give you, having seen nothing of your system, could be misleading or worse, harmful.