I'm about to replace a relay with a discrete triac design. The load is a (resistive) heater element and power 1200W @ 240V (RMS current ~5A). I will use zero crossing detection and max switching frequency of 1Hz. Environment temperature < 50C. The triac is fired from an mcu via optocoupler.
I'm looking for advices to create a robust solution from a practical point of view and in particular from field experience.
- What rating should the triac have for V and A.
- Is it possible/advisable to avoid a heat sink?
- Voltage surges are common in the region, how will that effect component selection?
- Can a (fast) fuse be effective in protecting the triac from short circuit and power surge? If not, are there known working solutions for circuit protection.
Thanks in advance!