rodoffshore
Member
Can a 208 delta primary with 208Y/120 secondary be used to replace a 230 delta primary with 230 secondary that is to be used as an isolation transformer for a 208 vfd? Both isolation transformers are rated at 51kVA.
isolation transformer
- Thread starter rodoffshore
- Start date
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LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Rod, welcome to the forum! 
If the question is whether you can use the 208-to-208Y/120 transformer as an isolation transformer, the answer is yes. Plus, the secondary neutral provides a most convenient method of bonding the SDS unless you plan to float it.
As to whether the VFD would be happy with that as a supply, I can't say, having little experience applying them. Others here will no doubt provide more info. (Just try and stop them.) Just for starters, what is the load current?
If the question is whether you can use the 208-to-208Y/120 transformer as an isolation transformer, the answer is yes. Plus, the secondary neutral provides a most convenient method of bonding the SDS unless you plan to float it.
As to whether the VFD would be happy with that as a supply, I can't say, having little experience applying them. Others here will no doubt provide more info. (Just try and stop them.
) Just for starters, what is the load current?- Status