Actual Deflection in STAAD Using Eurocode

Hi.

I obtained .663m as actual deflection in STAAD using Eurocode (EN1993-1-1:2005).

When checked thru manual computation of deflection, result was different.

I have 1.6kN/m^2 uniform load acting on UPN Channel with beam's length 4.1m.

Does this have anything to do with the difference in their sign convention?

Also, does STAAD use other formula in getting the deflection?

I'm using .

Please help.