Typically when editing Revit families, if you want to deal with arrays and stop them breaking when the count is 1, you set up some IF() formulas in Revit. However, a recent comment by David over on Revit Beginners describes another possible method:
Thank you Luke. Another possible solution is to nest the element into an adaptive component family, then nest the adaptive onto a conceptual mass family surface and use the repeater tool which can have an array count of 1.
I posted about this method a while back:
Download the example file here