3 Phase Delta-Wye or Delta-Delta Transformer
3 Phase Delta-Wye or Delta-Delta Transformer
(OP)
I have a client that has a 2400V distribution voltage (fed from 3 phase, delta-delta, 3 wire transformers). I need to use this feed to feed a 480V motor, hence fed from a transformer. My question is, if the 2400V is delta, 3-wire, can I use a 2400V-480/277V delta-Wye or 2400V-480/240V delta-delta transformer?






RE: 3 Phase Delta-Wye or Delta-Delta Transformer
RE: 3 Phase Delta-Wye or Delta-Delta Transformer
I agree with davidbeach and want to ask: You think you may need 240V better than 277V for future single phase loads?
RE: 3 Phase Delta-Wye or Delta-Delta Transformer
Obviously you are not in North America or USA. 480Y/277 is most common voltage for commercial and industrial facilities here. (600Y/347V in Canada, I beleive)
Industrial and commercial lighting is 277V or 347V here.
For the type of single phase loads you are refeering to (240V) which is common in Europe and Asia are served using 208Y/120V or 240/120V services obtained by stepping down 480V or 600V supply.
RE: 3 Phase Delta-Wye or Delta-Delta Transformer
respectfully
RE: 3 Phase Delta-Wye or Delta-Delta Transformer
RE: 3 Phase Delta-Wye or Delta-Delta Transformer
I didn't assume single transformers.
From the original post, I did assume that the load may be only one motor.
I also suspected that the transformer had not yet been aquired.
For a small three phase motor load, I stand by my suggestion.
Open delta is often used for for small three phase loads economic reasons.
Respectfully
RE: 3 Phase Delta-Wye or Delta-Delta Transformer
RE: 3 Phase Delta-Wye or Delta-Delta Transformer
RE: 3 Phase Delta-Wye or Delta-Delta Transformer
Plus there is no benefit of delta-delta. If anything it is uncommon setup and creates other grounding or non-grounding related issues. Unless there is a reason not to use Delta-wye, use it. It is the most common configuration in use, and it is for a reason.
RE: 3 Phase Delta-Wye or Delta-Delta Transformer
Not sure where you are located, but a regulation in many countries state that every electrical systen rated at greater than 50V (UK, South Africa) shall be connected to earth. From a safety point of view this would indicate a delta-star transformer.
Regards
Ralph
Failure seldom stops us, it is the fear for failure that stops us - Jack Lemmon
Make the best use of Eng-Tips.com
Read the Site Policies at FAQ731-376