Typical commissioning tests performed on Intelligent Electronic Devices (IEDs) consist of testing individual aspects of their algorithms, however, for some protection functions, these are not enough. Such is the case of the distance function, where typical natural phenomena of the Electric Power System (EPS) such as transient voltage and Source Impedance Ratio (SIR) variation, produce a transient overreach and a delay in the speed operate of zone 1. To determine these weaknesses, IEC 60255-121 standard defines the dynamic performance tests of the distance function in commercial IEDs. This paper presents a methodology that improves the dynamic test schemes defined in IEC 60255-121. The proposed methodology is applied to two different manufacturers of commercial IEDs used in the Ecuadorian Transmission System. Finally, the results obtained are compared and presented.