Unbalance delta load connected to star source 1

[saadicarnot]

Hi,

I want to know the implications of connecting unbalanced delta load to secondary (Star Winding) of transformer.

Thanks.

 

[itsmoked]

Neutral current, possibly lots.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Skogsgurra]

An unbalanced delta load. That means no neutral, so there shouldn't be any current in it.

It depends on the primary winding. If it is a delta winding, then your ampere-turns will be OK. If it is a wye winding - the ampere-turns do not agree so well and you get voltage drops.

Is it a Y/Y or a D/Y transformer?



Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[saadicarnot]

Its a D/Y Trafo

 

[Skogsgurra]

Shouldn't be a problem then.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[saadicarnot]

Dear Skogsgurra

Can you suggest some reading material on this topic ?

Thanks.

 

[waross]

You will have unbalanced line currents on the delta side.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[waross]

Ge publication The Whys of the wyes.

http://www.electricalmanuals.net/manuals/application-handbooks/ge/23-get-3388b

You will have to register on the site.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[itsmoked]

An unbalanced delta load. That means no neutral, so there shouldn't be any current in it.

Yes, but it's hooked up to a WYE transformer, hence there is a neutral.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[sibeen]

Is the centre of the star point earthed?

 

[saadicarnot]

Yes it is earthed.

 

[Skogsgurra]

Sorry to be a bore. But, if there's a wye secondary, and the load is delta. Where can any neutral current flow?

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[sibeen]

OK, if it is earthed then there is no big deal. If it was floating, then that's a different kettle of fish.

 

[sibeen]

Egad, belay all that. I've just realised that the load is delta (thanks, Gunnar - and an abashed grin). Doesn't matter if it is earthed or not.

 

[stevenal]

Let me try. There is a neutral point at the transformer wye winding, none at the delta load, and no neutral current involved with this load.

 

[ShooterBoter]

@Skogsgurra "If it is a wye winding - the ampere-turns do not agree so well..."
Why wouldn't the amp-turns match in this case?