Hi Zs on one phase only

[Eric12]

Anyone come across this before? I was asked to do a Zs on a 3ph surge device; L1 was around 6 ohm, L2 & L3 around 0.11. Wired in singles from a Ryefeid and one earth conductor so cannot think why this might be low on one phase only.One thing I did see was L1 fuse at Ryefeid was doubled up with another circuit (dont know what as no labelling). Voltage to earth for each phase at surge was normal. Wish I had carried out a loop to Neutral while I was there but did not. Anyhow it's a mystery; any thoughts?

 

[AH86Spark]

Had this before, found by the DNO to be a corroded fuse carrier on a pole mounted fuse on their LV network