I want to get the sizing of the following electrical equipment. It will be a great help if the same can be made available in this thread:-

1. Generator transformer sizing
2. Auxiliery transformer sizing
3.Distribution transformer sizing
4. DG sizing
5. LT Panel sizing provided the out going amp ratings are known
6. Relay settinmg calculation
thanks in advance
regard
Saraswata

For sizing of Generator Transformer,there are no calculations b coz
GT RATING=GENERATOR RATING (MW)/POWER FACTOR
For aux t/f the rating is arrived as follows
Max capacity motor starting current plus all running equipment+10 to 20% % margin.I am herewith attaching a Excel sheet for ur reference.
Calculations are based on following
pf for motors is considered as 0.85
All motors are not continuous run.So Loading factor for continuous is taken as 0.9 and for intermittent run it is taken as 0.4.
In general there will be stand bye motors for critical loads,so running capacity only considered.Stand bye motor is not considered.
These are the assumptions,so go through it and ask for any doubt

This post was last modified: 03-11-2011 11:31 AM by adeelectricalktpp.

Thanks for your response. But there is no excel attachment. It will be best if you can give sample calculation sheet for all the equipment sizing.The attachment given herewith is not in line with the requirement.
Is there any e-book that can give us a detail idea in equipment sizing?

Please help.
Thanks in advance

best regard
saraswata

yes,excel sheet iam unable to upload,so converted to pdf and sent.Dear this is a calculation regarding Aux.Transformer only.

please send the attachment

send me ur mail id

My email id:-
saraswatapalit@yahoo.com

Once again thanks in advance.
Please send the equipment sizing data for DG,PT,CT also if possible..

best regard
Saraswata

SOON I WILL SEND ALL THE DETAILS OK

If you have any EXCELS then kindly mail those attachments to shaileshchvk@gmail.com

Lets share knowledge for more understanding.

One Specific point that I wanted to discuss:
Transformer Sizing:
Required VA=
{continuous rating (VA) + 60 % of Intermittent load (VA) + Rating of Largest Stand-by Equipment}/{Assumed Lumped Power Factor}

And if you can see that there are many software that talk about transformer sizing, they do it by calculating/ assigning Load factors for various equipments but can anybody tell if this is listed in any IEC/****....????

There is no perticular standard for sizing.Designer has to take care about the following
1.Voltagedrop
2.Temp levels of t/f
3.Important point is to condider the starting of a major load(highest KW on that PMCC) while all continuous and intermittent loads are in service