ATS46 on open delta and grounded delta distribution systems
There are some problems that may occur with corner grounded systems.
The input filter has capacitors from each line to a neutral point and then another capacitor from this neutral point to ground. Using a corner grounded system unbalances this filter and may increase the filter leakage current. Another problem is if there is a fault to ground of the grounded phase, then there is no fault current to detect the fault, but the SCRs on that phase are shorted out by the external short.
Similar problems may occur on ungrounded Delta systems.
One or more phases may have a high voltage with respect to ground. This may cause measurement irregularities that can affect the operation of the soft starter. This is not usually a problem with control board firmware version 3.0 IE07. With older version firmware, this may be a problem.
The open Delta may be problem for the ATS46 because the voltage may not be balanced when loaded. This may cause phase fault problems.
Do not recommend the open delta.