Connecting only two terminals of 3 phase supply ??

[rameghad]

Hi,
I have an appliance module which runs at 400 V and usually independent 3 modules of it are connected across 3 phase supply (across L1-L2, L1-L3, and L2-L3). My question is would it be possible to run only one module across let's say L1-L2 or L2-L3 and leave the other terminal of 3 phase supply open. Would there be differences in line voltage.

 

[Smart $]

Welcome to the forum... :thumbsup:

Essentially that's what you are doing with each of the three modules. Line voltage should stay close to nominal. Reducing the load on any line reduces voltage drop (I²R losses), so the line voltage at the single module will be slightly higher than when all three are connected. Several factors go into determining exactly how much, and you did not provide anywhere near enough detail to hazard even a guess...