Electrical Appliances for caravans

We are looking to buy a microwave & fan heater for our Elddis but rather than just take standard appliances along we were wondering if there are specific appliances that will not trip out the hook up?

The heater is to supllement the hot air blown sysatem which we find not so good in the cold mornings as we use our van thro the year.

I see that the m/waves sold generally at dealers are 700 watts and similar overns sold on the high street (at lower prices) are also of this power.

Thanks for all you help to us 'newbies'