[RE-wrenches] Three-Phase Generator feeding Series/Parallel Quad Stack

[William Miller]

Nick:

Here's my best guess:  The X240 is configured to work with power legs with 
180 degree phase differential.  A 3 phase source has 120 degree phase 
differential.   This 120 degree phase differential shows as some degree of 
direct short to the source.

Solution:  I would forego the X240 and change the stacking configuration to 
Classic stacking.  Eliminate any shared neutrals to avoid neutral over-current.

William Miller


At 08:09 AM 7/29/2008, you wrote:
>Hello good folks in the RE world! An off grid customer of mine has a VFX 
>Quad Stack wired exactrly like page 20 in the FX manual, including the 
>X-240 balancing transformerconnected to the panel output legs. He has been 
>feeding it with two legs of a three-phase diesel generator. IS THIS A 
>COMPLETE NO-NO??? HE KNOWS THAT IT WILL RESULT IN AN UNBALANCED GEN 
>OUTPUT, BUT SO FAR IT HAS BEEN WORKING OK, BUT WITH THE FOLLOWING GLITCH: 
>WITH THE GENSET OFF------THE OUTBACK POWER PANELOUTPUT BUSSES ARE BOTH 
>ENERGISED ONLY WHEN THE x-240 BREAKERS ARE ON. AS SOON AS THE GENERATOR 
>STARTS (AGS SYSTEM) THIS 20 AMP DOUBLE BREAKERSEE PAGE 20, X-240) TRIPS 
>IMMEDIATLEY, LEAVING HALF THE LOADS WITHOUT POWER (NO OUTPUT FROM THE LEG 
>2 INVERTERS TO THE HOT 2 OUT BUSS) i'M BAFFELED, COULD SOMEBODY PLEASE 
>EXPLAIN THIS SITUATION TO ME SO THAT i CAN HELP THEM OUT? Another 
>electrician told them that a buck/boost transformer (on the gen 
>output?)would be the fix. Thanks a bunch in advance for your help in this 
>serious matter. Nick Houser Off Grid Services, Powell River, BC