Sorry for the delay. Yes I have seen the diagram sent by the first expert, I just thought that you got another one pasted on the unit itself.
I asked because from the diagram, I did not see any black wire on the label and I am suspecting it could be the neutral wire from the plug which is only labeled "N" but did not specified the color of the wire.
Plus, when you specified the 1a, 1b, 2a-2b...etc...I can not see them on the diagram so I am not sure if this is the right diagram of your unit.
If we would trace the diagram that we have, seems the power cord brown went straight to a PC board with a relay to turn on the compressor as the power transfer from a brown to plenty of red wires.
That would be the line side.So, if the "N" that came from the power cord is colored black, then it should be connected to the bunch of blue wires connected together on the terminal block of which the picture that you sent seems correct.
Can you please post another angle of the terminal block that you have shoot that could clearly tell us which terminal the black and brown wires are connected?
Please indicate also which part of the unit the bunch of wires came from. I would suspect the small wires red and blue came from the w/motor on the diagram.
Then I notice the different shield of the orange, blue and white wires, where do these wires came from?
And the other bundle of wires, the smooth blue, red and brown??? are they together inside the black insulation
? Where do they came from?
Thank you and will be waiting for your reply.