Transformer Connection
- Thread starter danilo
- Start date
- Status
charlie tuna
Senior Member
- Location
- Florida
Re: Transformer Connection
if your talking about the voltage taps-???- they are usually adjustable at 2 1/2 volts per step..
if your talking about the voltage taps-???- they are usually adjustable at 2 1/2 volts per step..
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Transformer Connection
Help me with this one. What is meant by "dyn5" and "dyn7"?
Help me with this one. What is meant by "dyn5" and "dyn7"?
beanland
Senior Member
- Location
- Vancouver, WA
Re: Transformer Connection
Dyn refers to delta on HV and grounded wye on LV. The number is the phase displacement (lead, lag). If you are not paralleling anything, the phase angle will have no impact. Check rotation.
Dyn refers to delta on HV and grounded wye on LV. The number is the phase displacement (lead, lag). If you are not paralleling anything, the phase angle will have no impact. Check rotation.
Re: Transformer Connection
Im actually connecting 3-333kva,1ph,34.5-480v in a bank..so you're saying it doesnt have any effect on secondary side?the design calls for a dyn7 but it turned out to be dyn5..say,the marked lead of phase A was tapped to unmarked lead of phase B instead of to unmarked lead of phase C..hope i didnt confuse you
thanks for your time
Danilo
Im actually connecting 3-333kva,1ph,34.5-480v in a bank..so you're saying it doesnt have any effect on secondary side?the design calls for a dyn7 but it turned out to be dyn5..say,the marked lead of phase A was tapped to unmarked lead of phase B instead of to unmarked lead of phase C..hope i didnt confuse you
thanks for your time
Danilo
Re: Transformer Connection
sorry guys for the confusion..
actually,dyn means delta at primary and grounded wye at secondary..if dyn5, it means the phase reference at secondary is pointing at 5'oclock and other phases are 120deg out of phase from each other.if dyn7,it means the reference phase is pointing at 7o'clock and other phases are also 120deg out of phase..from this positioning of phases,xformer connection at primary could now be determined..by referring your secondary connection to primary,it shows the proper way of connecting the leads of xformer.
In a 3xformer bank,for instance,the dyn5 says that the positive polarity lead of 1st xformer must be connected to the negative polarity lead of 2nd transformer but a mistake happened somewhere when instead of connecting the +polarity of 1st xformer to -polarity of 2nd xformer,the connection was made at -polarity of 3rd xformer..hope you get my point guys... ..what immediate effect does this connection bring to transformer operation?
gracias!
Danilo
sorry guys for the confusion..
actually,dyn means delta at primary and grounded wye at secondary..if dyn5, it means the phase reference at secondary is pointing at 5'oclock and other phases are 120deg out of phase from each other.if dyn7,it means the reference phase is pointing at 7o'clock and other phases are also 120deg out of phase..from this positioning of phases,xformer connection at primary could now be determined..by referring your secondary connection to primary,it shows the proper way of connecting the leads of xformer.
In a 3xformer bank,for instance,the dyn5 says that the positive polarity lead of 1st xformer must be connected to the negative polarity lead of 2nd transformer but a mistake happened somewhere when instead of connecting the +polarity of 1st xformer to -polarity of 2nd xformer,the connection was made at -polarity of 3rd xformer..hope you get my point guys...
..what immediate effect does this connection bring to transformer operation?gracias!
Danilo
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Transformer Connection
I cannot tell from your description, without having a wiring diagram in front of me, whether (1) You have the correct voltage at each of the secondaries, and (2) You have the three secondary windings 120 degrees apart from each other, and (3) The phase rotation (A-B-C) is correct. But if you do, then the result will be indistinguishable from the intended result. Selection of any given phase as the "reference phase," and selecting a point in time for that phase to be at the "zero degree reference point" are both arbitrary. What matters is the relationship among the three phases.
I cannot tell from your description, without having a wiring diagram in front of me, whether (1) You have the correct voltage at each of the secondaries, and (2) You have the three secondary windings 120 degrees apart from each other, and (3) The phase rotation (A-B-C) is correct. But if you do, then the result will be indistinguishable from the intended result. Selection of any given phase as the "reference phase," and selecting a point in time for that phase to be at the "zero degree reference point" are both arbitrary. What matters is the relationship among the three phases.
Re: Transformer Connection
what do you think?
regards,
danilo
thanks Charlie,i guess you're right..i would now assume it doesnt have any effect on the secondary side or in the operation of xformer in general..but im curious still on why the designer include this in his specification?if the load is pure inductive motors,does this dyn5 or dyn7 thing matter?
what do you think?
regards,
danilo
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Transformer Connection
When I specify transformers, I don't get into the wiring details. I just give a KVA rating, the voltage ratigns, the general wiring configuration (i.e., delta versus wye), and if appropriate a K-rating. The boilerplate specs also include a statement somewhere along the lines for the installer to verify phase rotation.
When I specify transformers, I don't get into the wiring details. I just give a KVA rating, the voltage ratigns, the general wiring configuration (i.e., delta versus wye), and if appropriate a K-rating. The boilerplate specs also include a statement somewhere along the lines for the installer to verify phase rotation.
Re: Transformer Connection
The DYN5 and DYN7 specifications sound like an IEC description of transformers.
I would guess that if the designer wanted a DYN7 connection and you made it DYN5, you'd run into problems if down the road there was a desire to parallel tranformer banks and you had a DYN5 paralleled with a DYN7.
I'll look around to see if I can find a spec sheet that describes the connections.
The DYN5 and DYN7 specifications sound like an IEC description of transformers.
I would guess that if the designer wanted a DYN7 connection and you made it DYN5, you'd run into problems if down the road there was a desire to parallel tranformer banks and you had a DYN5 paralleled with a DYN7.
I'll look around to see if I can find a spec sheet that describes the connections.
- Status