Effect Of 60&50Hz On The System.

Long time effect on what? Supply? Load?

I'd say there won't be much affect on the 50Hz supply, except cost.

Depending on what it is, a 60 Hz load may be a problem.

Motors will run at 5/6 normal speed. If they are lightly loaded, this may not be a problem, but if they are fully loaded, they may overheat and/or burn out. (Wrong volts/Hz ratio.) Heaters and incandescent lights will probably be okay.

Purely resistive loads shouldn't care, everything else requires further research. For example if the load happens to be a unit heater then the Btu output of the resistive element won't change, but the since the fan will run at approximately 83% of its 60 Hz speed the volume of air will be reduced to (0.83) cubed or 48% of normal (60Hz) air flow. Will the heating element overheat and burnout or will the conditioned space get too cold, both due to reduced air flow? Those are just a few of the questions you will need to consider for each and every device attached to your generator.

Apart from power factor correction and busbar sizing, this is one of CR4's principal topics. Try the "search all of CR4" box on the right.