ok, I've tried again as you suggested using 3 different resisters and croc clips.
resister measurement: 10ohms alone. With circuit L-L 11ohms, N-N 11ohms, E-E 12ohms.
resister measurement: 23ohms alone. With circuit L-L 23ohms, N-N 23 ohms, E-E 24ohms.
resister measurement: 47 ohms...