Is it mandatory to use heatsink and thermal interface with SSR P range of SSR (Solid State Relays).

SSR P (Panel mounting type SSR) are not with inbuilt heatsink compare to the integrated heat-sink
of SSR D (Din rail mounting type SSR) rerlays.

It is mandatory to use heatsink and thermal interface accessories for bettter thermal conductivity in between
SSR and enviroment in which it is mounted as it is designed with maximum operational temperature of 80' C.