JHHAMIII
New User
- Location
- Lakeland, Florida
I have a 3 phase 480/277 VAC feeder that I have connected to three (3) 1.5 KVA 240/480 to 24/48 VAC Buck Boost Transformers connected in a WYE configuration to get close to a 380/220VAC WYE system. The output voltage right now is L1-L2, 407 VAC, L2-L3 405 VAC and L1-L3 is 406 VAC, L1-Gnd is 236.5 VAC, L2-Gnd is 235.9 VAC, and L3-Gnd is 236.7 VAC. The WYE of the Buck Boost transformers is H1-H3 from each transformer connected together and I am reading 147.5 VAC from the un-grounded WYE (H1-H3) of all three (3) Buck Boost transformers connected together for the WYE to the grounded WYE 480/277 VAC feeder connected to the Buck Boost transformers. I want to ground the WYE of the Buck Boost Transformers so that I have zero Volts from the 480/277 VAC grounded WYE to the grounded WYE of the Buck Boost Transformers. This should give me close to a 221.6 VAC/383.8 VAC WYE system form the Buck Boost transformers. Can you confirm that I need to ground the WYE of the Buck Boost Transformers?
We are the Electrical Contractor installing the transformers to connect to a 380 50 HZ piece of equipment with 220 VAC controls connected from one phase to ground. We have told the customer that the motors on the system will run 20% faster from the 60HZ system, which they do not have a problem with.
They have recently been installed and we are about to connect and test the equipment by connecting it to either the ungrounded WYE from the Buck Boost Transformers or the grounded WYE of the Buck Boost Transformers. The 406 VAC average voltage from the ungrounded WYE of the Buck Boost transformers is within the +/- 10% voltage tolerance of the 380 VAC motors as that is from to 342 to 418 VAC.
The simplified question is it correct to ground the WYE of three (3) Buck Boost transformers connected in a three (3) phase WYE?
We are the Electrical Contractor installing the transformers to connect to a 380 50 HZ piece of equipment with 220 VAC controls connected from one phase to ground. We have told the customer that the motors on the system will run 20% faster from the 60HZ system, which they do not have a problem with.
They have recently been installed and we are about to connect and test the equipment by connecting it to either the ungrounded WYE from the Buck Boost Transformers or the grounded WYE of the Buck Boost Transformers. The 406 VAC average voltage from the ungrounded WYE of the Buck Boost transformers is within the +/- 10% voltage tolerance of the 380 VAC motors as that is from to 342 to 418 VAC.
The simplified question is it correct to ground the WYE of three (3) Buck Boost transformers connected in a three (3) phase WYE?