I kind of smell a Delta connected cornverter here! Odor remnants of a Center Tap Grounded type Animal! (or the Ø Offset is verrrry harsh!).
Can see that the Autotransformer setups for Voltage Reduction are in Delta - Open Delta that is! (specs list Two 500 VA Xformers).
Appears that the EMF levels listed are within tolerance for said piece of Polyphase Machinery.
Speaking in many tongues...
p.s. This message is simple to decipher - just use a good book to reference
BTW; 208-228 VAC sounds kinda stange, unless this is something set directly for use on a 208Y/120 VAC 3Ø 4W system.
I'm commonly seeing specs at 200-208 VAC (200-208-215 VAC), or 200-208/230 VAC.
Not that this is default for every North American Equipment rating, only what's been seen by me.
Scott35 ... again