3 phase testing refresher needed please

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


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Many Thanks Andrew There was a blown phase in the master box further up the yard. Old fashioned 60 amp cartridge fuses, all of which have been bridged with fuse wire on unknown amp value. Total nightmare to be honest, the whole lot should be ripped out a re done in my opinion. Bob

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