Frequently Asked Questions

TAP Kiln Control Products are compatible with mechanical, mercury, and solid-state relays (SSRs). So, which type of relay is right for you? Generally, we recommend using solid-state relays: the upsides and long-term savings far outweigh the added upfront cost.  

Mechanical relays have moving parts. That means they’re 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.

(Also, while mechanical relays are less expensive upfront, regular replacement costs leads to them being the most expensive option in the long run.)

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. These days, they’re largely obsolete and even outlawed in states such as California. Mercury relays have largely been replaced by solid-state relays.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 to mechanical or mercury alternatives in lifetime, performance, and environmental considerations. However, their Achilles heel is heat. SSRs 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 a solid-state the next time they need replacement!

You can learn more about kiln relays at this blog article. Additionally, if you want a limit controller that you can wire to a redundant safety relay to protect you if yours fail, we recommend investing in TAP Monitor for added safety!