I would say a microwave is a small appliance if you can carry it (you can't carry a dishwasher or washing machine or fridge so those I would think are large appliances)?
@corinnec@narayani@seacreature@casablanca@pcoulson well, although it was quite heavy* I could carry it (up the steps which had been gritted for ice), but held to one side in my arms so I could see my feet - but it was the transfer over the gap between the railings and the skip that was most difficult. [Desi's got the idea - but the sight of a man sauntering along with a broken kettle suggested to me that a "medium sized appliance pit" could be introduced to everyone's** benefit]
* all relative I suppose
** mine ;-D