Jeg har en SSR i en boks, og har lagt kjøleribben på utsiden. Da slipper du styr med vifte, og flere åpninger i boksen. Bilde i denne posten
https://forum.norbrygg.no/threads/diy-sestos-pid-d1s-koblingsdiagram-og-deler.29353/
Jeg ville jordet kjøleribben hvis den er på utsiden og det er berøringsfare, egentlig uansett.
Her er hva Auber sier generelt om SSR og kjøling,
http://auberins.com/index.php?main_page=page&id=10&chapter=0
3. Do I need a heat sink for the SSR?
SSRs are made of semiconductors that have limited conductance. When passing a current, heat will be produced. Each ampere of current will produce about 1.3 to 1.5 watts of heat. When a 12 amps current passes through a SSR, approximately 16 watts of heat will be produced in the SSR. As more heat is produced, temperature inside the SSR will rise. The Maximum temperature on the metal surface of the SSR should not pass 70 °C (158 °F). If it rises above 70 °C, the SSR will not shut off and eventually get damaged. High temperature can also shorten the life or damage other components in the same box.
The temperature of the SSR depends on the amplitude of the current, duty cycle, and the ambient temperature. The rule of thumb is that if the current is more than 8 ampere, you will need a heat sink or mount it on a thick aluminum sheet. If it is more than 15A, you need either to use a 25A external heat sink or a 40A SSR heat sink or forced air (with fan). Increasing the capacity of the SSR (using a 40A SSR instead of 25A SSR for a 15A load) will not significantly reduce the heat; a heat sink is still needed. However, higher capacity SSR is structurally more durable. When more than 30A is passed, the box that holds the internal SSR needs to have good ventilation with forced air.
In most cases, the heat generating on SSRs is only an issue during the beginning stage of a heating process when the heater is running at full power. Once the temperature is close to the set point, it will probably take less than 50% of the power to maintain the temperature. Since the generated heat is directly related to the current passing through the SSR, the heat produced at steady state might be insignificant and can be ignored. For 12 Amp load, if you system takes less than 3 minutes to heat up to the steady state, you might not need a heat sink
.a typical case for home espresso machine.
