Well, since this is a medium ship, 1,000 or above is a bit too upgraded.
Also, this is a 2nd class so may be range from 600-800 km/h.
Also, be more specific what exactly does the EMP cannon shut down? If it is the entire ship, all in one blast... I'd have to label that as over-powering.
Calrify, and edit if neccessary.