I wish to use a ssr to switch an element in a 240v coffee machine. Load is 4000w. I would like to know what rating ssr to use. Coffee machines are rather warm environments (at least 40-50C) and I understand that ssr efficiency is related to their ability to dissapate heat.
4 kW for a coffee machine seems a lot. That is about 17A.
A 25 A SSR should be OK if bolted to a good heat sink. However, a quick look on Farnell showed a 25A ssr for £20 and a 50 A one for £27, so for a one-off it may not be worth pushing it.