All of the TAP Kiln Controllers are compatible with mechanical, mercury, and solid state relays – but we strongly recommend using a solid state relay.
TAP Kiln Controllers are compatible with mechanical, mercury, and solid state relays. So which type of relay is right for you? Generally, we recommend using solid state relays, as the upsides far outweigh the added costs.
Mechanical relays have moving parts and are subject to normal wear and tear. They will fail eventually, it’s just a matter of when. That’s why it’s super important to have a defined preventative maintenance plan when working with mechanical relays. Change them before they fail or suffer the consequences of a ruined project or worse.
Mercury relays were a great substitute for mechanical relays in that they weren’t subject to the same contact erosion in high current applications. However, they use the highly toxic liquid metal mercury to perform switching. As such they’re largely obsolete and even outlawed in states such as California. They’ve largely been replaced by solid state relays.
Solid State relays have no moving parts and aren’t subject to the same wear and tear considerations as mechanical relays. They are superior in lifetime, performance, and environmental considerations than mechanical or mercury alternatives. However, their Achilles heel is heat. Solid State Relays must be appropriately cooled via heat sink to maintain proper performance and prevent melting.
Most new kilns have the option for solid state relays – you should strongly consider choosing that option. If you’ve got an older kiln with mechanical or mercury relays, consider swapping them out for solid state the next time they need replacement!