3 Phase problems

[millwall ken]

Hi all,
can someone please provide me with a list of the most common faults that you will encounter with 3 phase equipment such as ac units, motors, etc.
Cheers Boys.

 

[millwall ken]

no control circuit voltage, look for a 'phase sequence' or 'phase rotation/detection' relay. as the name suggests this protects against incorrect direction of rotation of motors and pumps or anything really where this is a critical factor or may detect the loss of a phase. three phases connected correctly will energise and onboard relay to enable your control circuit.

Note taken fella, you're a diamond.