Corner Delta Grounded
Corner Delta Grounded
(OP)
In the case of a Delta (primary) - corner delta grounded (secondary), is one of the phase physically connected to its core or body? If we purchase this type of transformer, is one phase actually pre-connected to its body? I appreciate if someone also provide me a link for this?
Thanks
Thanks






RE: Corner Delta Grounded
I would just buy a standard delta-delta transformer.
Actually, what I'd probably do is try to find a different solution. Corner-grounded delta systems are rare and not something most electrician or linemen are used to dealing with. Best to avoid them if at all possible.
RE: Corner Delta Grounded
RE: Corner Delta Grounded
I'm not sure what you mean about "voltage-to-ground reading (on R-S, S-T, R-T)". Either you would be measuring R-G, S-G, T-G or you would be measuring R-S, S-T, T-R, but there is no R-S to G voltage that would have any meaning.
RE: Corner Delta Grounded
RE: Corner Delta Grounded
RE: Corner Delta Grounded
One other disadvantage of a fixed-winding-to-ground transformer winding is the inability to check the winding’s insulation resistance.
RE: Corner Delta Grounded
Your best solution will be to buy a delta-delta transformer, which have the main advantage of insulating the zero sequence networks = less 1 phase short circuit current. Unfortunately Dd transformers are more expensive than Yd transformers. This is because all HV insulation is rated for the HV level, in comparison with Yd transformer, where its HV insulation is gradually reduced through its neutral (earthing point).
In addition, you can monitor the insulation of the phases to earth in the distribution system, by installing an earthing transformer, usually called zig-zag transformer.