Try this way.
Say sheet1 contains column name as employee, ID, Salary,
sheet2 contains sames fields & similarly sheet3 also contains the same.
Now there is a sheet called Total contains same columns Names Employee, ID, Salary,

In Order to get consolidated information from three sheets 1,2,3 into total.
step 1.
In sheet Total, put columnA "=sheet1A1" ColumnB=Sheet1B1", ColumnC="Sheet1C1" and drag down till 1000 rows.
step 2.
from 1001th Row in sheet total
1001th row column A "=Sheet2A1", Column B"=Sheet2B1", Column C"=Sheet2C1" drag from 1001th row to 2000th row in total sheet
step 3.
Similarly drag 2001th row to 3000th row "Sheet3A1", "Sheet3B1", "Sheet3C1" in Column A, Column B, Column C.
Step 4.
Use pivot table in sheet "Total" for Columns A,B,C till 3000 rows.