Connecting multiple single phase loads to 3 phase delta-wye transformer

[Tumel]

Hi Engineers, I am wondering, How would you connect four single phase loads to a secondary winding of delta-wye transformer since there are only three windings and not four. Given that phase-to-phase voltage is 400 V and phase-to-neutral voltage is 230 V. How do you ensure load balance in that?

 

[cranky108]

If balance is your aim, then you would need to know the load of each of the loads, specified in KVA.

 

[RRaghunath]

While it is good engineering practice to maintain load balance in LV system, it may not be always possible. Yours seems to be one such case. Go ahead and connect if you have no alternative. The system is anyway designed to withstand unbalanced loading and neutral currents.

 

[edison123]

It depends on what are the 4 single phase loads. For example, 2 loads are X KW each and other two loads are X/2 KW each, then you just distribute X/X/(2 x X/2) in each phase.

Muthu

http://www.edison.co.in

 

[prc]

With Dy transformers and effectively grounded primary system, any unbalance in load on Y side will be seen on primary side as balanced load. To my understanding , this is one of the main reason to adopt Dy connection for distribution transformers; the other being third harmonics from load will not get in to primary system as it will be trapped in the delta. Also secondary side LG faults will not affect primary ground relays.