Radiator selection recommendations:As the SSR components emit heat in operation, the relay must have good cooling. It can be natural cooling, cooling with a radiator, cooling with a radiator and a fan. At a load of about 5%, only natural cooling can be used, at a load of over 10%, it is advisable to add a radiator, more than 40% must be added and a fan.Additionally, the seasonal and geographic temperature of the environment is having a major impact. It is also necessary to keep in mind the workspace in the electric panel itself, in which the SSR is mounted.As a final result, the decisive indicator of good cooling selection is the temperature reached in the heaviest mode of relays, which should not exceed 70 ℃