3 phase systems

Thread Starter

chuck 1

Joined Aug 14, 2011
2
we have machines that won't run when we have a ground on 3 phase delta system, how do you safely ground 1 phase to test ground fault
 

RRITESH KAKKAR

Joined Jun 29, 2010
2,829
That's Good question...!!

Just for checking grounding you have to use Multimeter connect one probe of meter to ground and other to neutral note reading, then check live and neutral voltage.
on comparing then you can know the quality of groundong.
Ideally it is 0V ..
 

shortbus

Joined Sep 30, 2009
10,045
That's Good question...!!

Just for checking grounding you have to use Multimeter connect one probe of meter to ground and other to neutral note reading, then check live and neutral voltage.
on comparing then you can know the quality of groundong.
Ideally it is 0V ..
Bad information:( There is no 'neutral' in three phase.
 

shortbus

Joined Sep 30, 2009
10,045
just as 'bad'. there may be a grounded center tap in a delta, and the central point of a wye may be brought out, in which case code requires it to be grounded. both being three phase.
But like I said there is no 'neutral'. Ground is not considered neutral. With three phase there are three 'hots' and ground.
 

GetDeviceInfo

Joined Jun 7, 2009
2,192
But like I said there is no 'neutral'. Ground is not considered neutral. With three phase there are three 'hots' and ground.
Not so in the case of a wye with center brought out. You may be thinking 3 phase/ 3 wire, but 4 wire systems are very common.
 
Last edited:

Thread Starter

chuck 1

Joined Aug 14, 2011
2
we need to ground 1 phase of a 3 phase 575 vac system to check and train on how to use ground fault indicator/detector in plant because we have machines that won't run at all until we clear ground fault thks
 
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