Jpflex
Electrician big leagues
- Location
- Victorville
- Occupation
- Electrician commercial and residential
I installed 2 boost transformers once sourced from a delta delta ungrounded 300KVA, 4800/480 volt 3 phase transforber.Hey guys, I have looked all over the forum and beyond for help on buck boost wiring. I believe I have an understanding of Single Phase Buck Boost Transformers but when I try to apply the math to a 3 Phase System. I am not coming out with numbers that make sense. I hope that the forum community can shed some light.
I do have a specific question in mind but I'd like to ask a general question to help me, and hopefully others, grasp the method of bucking or boosting a 3 phase system to a different 3 phase voltage using 2 Single Phase Buck Boost Transformers. This may be the key for my other question and probably the rest to come.
The photo attached is one of the wirings in question.
According to this diagram, I will get 208V between A+B and B+C but not A+C. Does that sound correct?
For example, I have 218V Input and I want a 208V Output. This wiring configuration only drops voltage on A and C Leg.
I cannot run a 208V 3 Phase Equipment with significantly lower voltage between the A+C Leg . Yet, this is the diagram I was referenced to from the Buck Boost Transformer.
I believe my math or my understanding..or both... is incorrect somewhere.
I've attached a photo of the nameplate of the transformer to assist with any info.
I'd appreciate any help.
The boost transformer stepped up the 480 volts to 575 volts for a specific motor set up. I remember having to hook up a jumper between both boost transformers but although it was confusing at first, my first wiring attempt was correct
The second diagram in your post makes sense except the last part where putting the secondary windings in parallel X3 to X1 and x2 to x4 which the diagram show to yield a higher voltage?
The opposite should be true since there are less series windings in boost rotation direction and less voltage impressed across each individual coil loop why then does it show a secondary boost effect?
When the primary windings are placed in parallel it is for a smaller voltage input as expected?