OH3 - Means that the temperature inside the inverter exceeds the allowable value. Please check the following for possible causes and measures.
One point advice
From the program mode menu 5 "Maintenance information list", you can check the maximum value of inside air temperature.
How to check the inside air temperature maximum value
* In order to monitor the maximum value of the inside air temperature, E52 (Touch panel menu selection) data to "2 (Full Menu Mode)" in order to display the data.