My workshop seems to have lost its 3 phase supply, all 3 Bridgeport's are showing nothing on the CNC screens, as opposed to flashing red lights when power has been interrupted. Manual Bridgeport buzzes, and tries to turn, but doesn't, phase down in my book ?
I cant remember the correct way to test if a phase has gone down, and my testing gave different results ?
If I put a volt meter across 2 of the 3 phases, in various combinations, I don't get a reading in one combination ?
I put a volt meter on each phase, red, blue, yellow (I know old colours) to earth, and get a reading on each of about 130 volts, may be even 150 ?
Confuses me............... Refresher course most welcomed